Bryant Legacy 674D Installation Instructions Manual

674D
LEGACYt 13 SEER SINGLE--PACKAGED HYBRID HEAT DUAL FUEL
SYSTEM WITH PURONR (R--410A) REFRIGERANT
SINGLE AND THREE PHASE
2--5 NOMINAL TONS (SIZES 24--60)

Installation Instructions

NOTE: Read the entire instruction manual before starting the

installation.

NOTE: Installer: Make sure the Owner’s Manual and Service
Instructions are left with the unit after installation.

TABLE OF CONTENTS

PAGE

SAFETY CONSIDERATIONS 1--2.......................

INTRODUCTION 2...................................

RECEIVING AND INSTALLA TION 2--13.................

Check Equipment 2..................................

Identify Unit 2....................................

Inspect Shipment 2.................................

Provide Unit Support 2...............................

Roof Curb 2......................................

Slab Mount 7.....................................

Field Fabricate Ductwork 7............................

Provide Clearances 7.................................

Rig and Place Unit 7.................................

Connect Condensate Drain 7...........................

Install Flue Hood 8...................................

Install Gas Piping 8..................................

Install Duct Connections 11............................

Configuring Units for Downflow (Vertical)

Discharge 11.....................................

Install Electrical Connections 12........................

High--Voltage Connections 12........................

Special Procedures for 208-- V Operation 12..............

Control Voltage Connections 12.......................

Balance Point Setting Thermidistat or Hybrid Heat

Thermostat 13....................................

Transformer Protection 13...........................

PRE--START--UP 13...................................

START--UP 14--17.....................................

Check for Refrigerant Leaks 14.........................

Unit Sequence of Operation 14.........................

Start--Up Heating and Make Adjustments 14...............

Checking Heating Control 15.........................

Check Gas Input 15................................

Adjust Gas Input 15................................

Check Burner Flame 16.............................

Start--Up Cooling and Make Adjustments 18...............

Physical Data 17....................................

Checking Cooling Control Operation 17................

Checking and Adjusting Refrigerant 17.................

Indoor Airflow and Airflow Adjustments 17.............

MAINTENANCE 29--34................................

Air Filter 29........................................

Indoor Blower and Motor 29...........................

Flue Gas Passageways 30..............................

Limit Switch 30.....................................

Burner Ignition 30...................................

Main Burners 30....................................

Outdoor Coil, Indoor Coil, & Condensate Drain Pan 30......

Outdoor Fan 31.....................................

Electrical Controls and Wiring 31.......................

Refrigerant Circuit 31.................................

Gas Input 32........................................

Indoor Airflow 32...................................

Check Defrost Thermostat 32...........................

PuronR Items 32....................................

TROUBLESHOOTING 35..............................

START--UP CHECKLIST 35............................

VERTICAL ECONOMIZER 39--56.......................

General 39.........................................

Accessories 39......................................

Installation 39-- 45...................................

Small Chassis 39-- 40...............................

Large Chassis 43--45...............................

CONFIGURATION 4 6--52..............................

OPERATION 53......................................

TROUBLESHOOTING 54..............................

SAFETY CONSIDERATIONS

Installation and servicing of this equipment can be hazardous due
to mechanical and electrical components. Only trained and
qualified personnel should install, repair, or service this equipment.

Untrained personnel can perform basic maintenance functions such
as cleaning and replacing air filters. All other operations must be
performed by trained service personnel. When working on this
equipment, observe precautions in the literature, on tags, and on
labels attached to or shipped with the unit and other safety
precautions that may apply.

Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Have fire extinguisher available. Read these
instructions thoroughly and follow all warnings or cautions
included in literature and attached to the unit. Consult local
building codes, the current editions of the National Fuel Gas Code

A09034

Fig. 1 -- Unit 674D ----A

1

(NFGC) NFPA 54/ANSI Z223.1, and the National Electrical Code
(NEC) NFPA 70.

In Canada refer to the current editions of the National Standards of
Canada CAN/CSA--B149.1 and .2 Natural Gas and Propane
Installation codes, and Canadian Electrical Code CSA C22.1.

Recognize safety information. This is the safety--alert symbol
When you see this symbol on the unit and in instructions or manu­als, be alert to the potential for personal injury. Understand these
signal words: DANGER, WARNING, and CAUTION. These
words are used with the safety--alert symbol. DANGER identifies
the most serious hazards which will result in severe personal injury
or death. WARNING signifies hazards which could result in per­sonal injury or death. CAUTION is used to identify unsafe practic­es which ma y result in minor personal injury or product and prop­erty damage. NOTE is used to highlight suggestions which will
result in enhanced installation, reliability, or operation.

!

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury or death.

674D-- --A

Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be
more than one disconnect switch. Turn off accessory heater
power switch if applicable.

!

WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in personal
injury, death or property damage.

A qualified installer or agency must use only
factory--authorized kits or accessories when modifying this
product.

!

CAUTION

CUT HAZARD

Failure to follow this caution may result in personal injury.

When removing access panels (see Fig. 18) or performing
maintenance functions inside your unit, be aware of sharp
sheet metal parts and screws. Although special care is taken
to reduce sharp edges to a minimum, be extremely careful
when handling parts or reaching into the unit.

INTRODUCTION

The 674D----A unit (see Fig. 1) is a fully self--contained,
combination Category I gas heating/electric heating and cooling
unit designed for outdoor installation (See Fig. 2 and 3 for unit
dimensions). All unit sizes have return and discharge openings for
both horizontal and downflow configurations, and are factory
shipped with all downflow duct openings covered. Units may be
installed either on a rooftop, or on a cement slab (See Fig. 4 for
roof curb dimensions).
In gas heating mode, this unit is designed for a minimum
continuous return--air temperature of 55_F(13_C) db and a
maximum continuous return--air temperature of 80_F(27_C) db.
Failure to follow these return--air temperature limits may affect
reliability of heat exchangers, motors, and other components.
Models with an N in the thirteenth position of the model number
are dedicated Low NOx units designed for California installations.
These models meet the California maximum oxides of nitrogen

(NOx) emissions requirements of 40 nanograms/joule or less as
shipped from the factory and must be installed in California Air
Quality Management Districts or any other regions in North
America where a Low NOx rule exists.

RECEIVING AND INSTALLATION

Step 1 — Check Equipment

.

IDENTIFY UNIT
The unit model number and serial number are stamped on the unit

information plate. Check this information against shipping papers.
INSPECT SHIPMENT

Inspect for shipping damage before removing packaging materials.
If unit appears to be damaged or is torn loose from its anchorage,
have it examined by transportation inspectors before removal.
Forward claim papers directly to transportation company.
Manufacturer is not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify the
nearest equipment distribution office if any item is missing. To
prevent loss or damage, leave all parts in original packages until
installation.

If the unit is to be mounted on a curb in a downflow application,
review Step 9 to determine which method is to be used to remove
the downflow panels before rigging and lifting into place. The
panel removal process may require the unit to be on the ground.

Step 2 — Provide Unit Support

For hurricane tie downs, contact distributor for details and PE
(Professional Engineering) Certificate if required.

ROOF CURB
Install accessory roof curb in accordance with instructions shipped

with curb (See Fig. 4). Install insulation, cant strips, roofing, and
flashing. Ductwork must be attached to curb.

IMPORTANT: The gasketing of the unit to the roof curb is
critical for a water tight seal. Install gasketing material supplied
with the roof curb. Improperly applied gasketing also can result in
air leaks and poor unit performance.

Curb should be level to within 1/4 in. (6 mm). This is necessary for
unit drain to function properly. Refer to accessory roof curb
installation instructions for additional information as required.

Installation on older “G” series roof curbs.

Two accessory kits are available to aid in installing a new “G”
series unit on an old “G” roof curb.

1. Accessory kit number CPADCURB001A00, (small chassis)
and accessory kit number CPADCURB002A00, (large
chassis) includes roof curb adapter and gaskets for the
perimeter seal and duct openings. No additional
modifications to the curb are required when using this kit.

2. An alternative to the adapter curb is to modify the existing
curb by removing the outer horizontal flange and use
accessory kit number CPGSKTKIT001A00 which includes
spacer blocks (for easy alignment to existing curb) and
gaskets for the perimeter seal and duct openings. This kit is
used when existing curb is modified by removing outer
horizontal flange.

!

UNIT/STRUCTURAL DAMAGE HAZARD

Failure to follow this caution may result in property damage.

Ensure there is sufficient clearance for saw blade when cutting
the outer horizontal flange of the roof curb so there is no
damage to the roof or flashing.

CAUTION

2

674D-- --A

A09473

Fig. 2 -- 674D-- -- A24--36 Unit Dimensions

3

674D-- --A

A09474

Fig. 3 -- 674D-- -- A42--60 Unit Dimensions

4

HVAC unit
base rails

Anchor screw

Flashing field
supplied

Roofing material
field supplied

Cant strip
field supplied

HVAC unit
basepan

Sealing
Gasket

Roofcurb

Wood nailer*

Roofcurb*

Insulation
(field supplied)

B

G

C

H

F

A

D

E

*Provided with roofcurb

ROOF CURB DETAIL

A

F

SMALL CURB

A09090

A09418

674D-- --A

B

C

G

H

E

D

LARGE CURB

UNIT SIZE

Small

Large

NOTES:

1. Roof curb must be set up for unit being installed.

2. Seal strip must be applied, as required, to unit being installed.

3. Roof curb is made of 16-- gauge steel.

4. Attach ductwork to curb (flanges of duct rest on curb).

5. Insulated panels: 1--in. (25.4 mm) thick fiberglass 1 lb. density.

CATALOG

NUMBER

CPRFCURB010A00 11 (279)
CPRFCURB011A00 14 (356)
CPRFCURB012A00 11 (279)
CPRFCURB013A00 14 (356)

IMPORTANT: Do not install large base pan HYBRID HEAT
units onto the small base pan (common curb). The center of gravity
on a large base pan HYBRID HEAT unit could overhang the curb
causing an unsafe condition. Before installing any large base pan
unit onto the common curb, check the “Y” distance in the product

A

IN. (mm)BIN. (mm)*

C

IN. (mm)DIN. (mm)EIN. (mm)FIN. (mm)GIN. (mm)HIN. (mm)

10 (254)

16 (406)

14 (356)

47.8

(1214)

literature dimensional drawing to ensure that “Y” is greater than 14
in. (356 mm). Do not install any large base pan unit onto the
common curb with a “Y” dimension (center of gravity) less than 14
in. (356 mm).

Fig. 4 -- Roof Curb Dimensions

5

A09415

32.4 (822)

43.9

(1116)

2.7 (69)

A09419

30.6 (778)

46.1 (1170)

42.2 (1072)

CAUTION - NOTICE TO RIGGERS
PRUDENCE - AVIS AUX MANIPULATEUR

PANNEAUX D'ACCES DOIT ÊTRE EN PLACE POUR MANIPULATION.

Use top skid as spreader bar. / Utiliser la palette du haut comme barre de répartition

ACCESS PANELS MUST BE IN PLACE WHEN RIGGING.

DUCTS

MINIMUM HEIGHT: 36" (914.4 mm)
HAUTEUR MINIMUM

SEAL STRIP MUST BE IN

UNIT HEIGHT
HAUTEUR D'UNITÉ

674D-- --A

SEE DETAIL A
VOIR DÉTAIL A

RIGGING WEIGHTS (SMALL CABINET) RIGGING WEIGHTS (LARGE CABINET)

Unit

Rigging

Weight

*For 460 Volt units add 14 lb (6.35 kg) to the rigging weight.
NOTE: See dimensional drawing for corner weights.

24 30 36

lb kg lb kg lb kg lb kg lb kg lb kg

359 163 373 169 379 172

Rigging

Weight

VOIR DÉTAIL A

Unit

DETAIL A

461 209 482 219 507 230

PLACE BEFORE PLACING
UNIT ON ROOF CURB

42 48 60

BANDE SCELLANT DOIT ÊTRE
EN PLACE AVANT DE PLACER
L'UNITÉ SUR LA BASE DE TOIT

50CY502286 2.0

A09051

Fig. 5 -- 674D-- -- A Suggested Rigging

6

SLAB MOUNT

Place the unit on a solid, level concrete pad that is a minimum of 4
in. (102 mm) thick with 2 in. (51 mm) above grade. The slab
should be flush on the compressor end of the unit (to allow
condensate drain installation) and should extend 2 in. (51 mm) on
the three remaining sides of the unit. Do not secure the unit to the
slab except when required by local codes.

Step 3 — Field Fabricate Ductwork

Secure all ducts to roof curb and building structure on vertical
discharge units. Do not connect ductwork to unit. For horizontal
applications, unit is provided with flanges on the horizontal
openings. All ductwork should be secured to the flanges. Insulate
and weatherproof all external ductwork, joints, and roof openings
with counter flashing and mastic in accordance with applicable
codes.

Ducts passing through an unconditioned space must be insulated
and covered with a vapor barrier.

If a plenum return is used on a vertical unit, the return should be
ducted through the roof deck to comply with applicable fire codes.

See unit rating plate for any required clearances around ductwork.
Cabinet return --air static shall not exceed --.2 IN. W.C.

Step 4 — Provide Clearances

The required minimum operating and service clearances are shown
in Fig. 2 and 3.

IMPORTANT: Do not restrict outdoor airflow. An air restriction
at either the outdoor--air inlet or the fan discharge may be
detrimental to compressor life.

The condenser fan pulls air through the condenser coil and
discharges it through the top grille. Be sure that the fan discharge
does not recirculate to the condenser coil. Do not locate the unit in
either a corner or under an overhead obstruction. The minimum
clearance under a partial overhang (such as a normal house
overhang) is 48--in. (1219 mm) above the unit top. The maximum
horizontal extension of a partial overhang must not exceed 48--in.
(1219 mm).

Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. Do not install the unit on
carpeting or other combustible materials. The unit may be installed
on Class A, B, or C roof covering materials. Slab mounted units
should be at least 4--in. (102 mm) above the highest expected water
and runoff levels. Do not use unit if it has been under water.

Step 5 — Rig and Place Unit

!

WARNING

PERSONAL INJURY OR PROPERTY DAMAGE
HAZARD

Failure to follow this warning could result in personal
injury, death or property damage.

When installing the unit on a rooftop, be sure the roof will
support the additional weight.

Rigging and handling of this equipment can be hazardous for
many reasons due to the installation location (roofs, elevated
structures, etc.).

Only trained, qualified crane operators and ground support staff
should handle and install this equipment.

When working with this equipment, observe precautions in the
literature, on tags, stickers, and labels attached to the equipment,
and any other safety precautions that might apply.

Training for operators of the lifting equipment should include, but
not be limited to, the following:

1. Application of the lifter to the load, and adjustment of the
lifts to adapt to various sizes or kinds of loads.

2. Instruction in any special operation or precaution.

3. Condition of the load as it relates to operation of the lifting
kit, such as balance, temperature, etc.

Follow all applicable safety codes. Wear safety shoes and work
gloves.

Inspection

Prior to initial use, and at monthly intervals, all rigging shackles,
clevis pins, and straps should be visually inspected for any
damage, evidence of wear, structural deformation, or cracks.
Particular attention should be paid to excessive wear at hoist
hooking points and load support areas. Materials showing any kind
of wear in these areas must not be used and should be discarded.

!

WARNING

UNIT FALLING HAZARD

Failure to follow this warning could result in personal
injury or death.

Never stand beneath rigged units or lift over people.

!

WARNING

PROPERTY DAMAGE HAZARD

Failure to follow this warning could result in personal
injury/death or property damage.

When straps are taut, the clevis should be a minimum of 36
in. (914 mm) above the unit top cover.

Rigging/Lifting of Unit (See Fig. 5)

Lifting holes are provided in base rails as shown in Fig. 2 and 3.

1. Leave top shipping skid on the unit for use as a spreader bar
to prevent the rigging straps from damaging the unit. If the
skid is not available, use a spreader bar of sufficient length
to protect the unit from damage.

2. Attach shackles, clevis pins, and straps to the base rails of
the unit. Be sure materials are rated to hold the weight of the
unit (See Fig. 5).

3. Attach a clevis of sufficient strength in the middle of the
straps. Adjust the clevis location to ensure unit is lifted level
with the ground.

After the unit is placed on the roof curb or mounting pad, remove
the top skid.

Step 6 — Connect Condensate Drain

NOTE: When installing condensate drain connection be sure to

comply with local codes and restrictions.

Model 674D ----A disposes of condensate water through a 3/4 in.
NPT fitting which exits through the compressor access panel (See
Fig. 2 and 3 for location).

Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in ground
level installations. Install a field--supplied condensate trap at end
of condensate connection to ensure proper drainage. Make sure that

the outlet of the trap is at least 1 in. (25 mm) lower than the
drain-- pan condensate connection to prevent the pan from
overflowing (See Fig. 6). Prime the trap with water. When using a
gravel apron, make sure it slopes away from the unit.

If the installation requires draining the condensate water away
from the unit, install a 2--in. (51 mm) trap at the condensate
connection to ensure proper drainage (See Fig. 6). Make sure that
the outlet of the trap is at least 1 in. (25 mm) lower than the
drain-- pan condensate connection. This prevents the pan from
overflowing.

Prime the trap with water. Connect a drain tube -- using a minimum
of 3/4--in. PVC or 3/4--in. copper pipe (all field--supplied) -- at the
outlet end of the 2-- in. (51 mm) trap. Do not undersize the tube.

7

674D-- --A

Pitch the drain tube downward at a slope of at least 1--in. (25 mm)
for every 10 ft (3 m) of horizontal run. Be sure to check the drain
tube for leaks.

TRAP
OUTLET

1-in. (25 mm) min.

2-in. (51 mm) min.

A09052

Fig. 6 -- Condensate Trap

Step 7 — Install Flue Hood

The flue assembly is secured and shipped in the return air duct.
Remove duct cover to locate the assembly (See Fig. 8 and 9).

NOTE: Dedicated low NOx models MUST be installed in
California Air Quality Management Districts where a Low NOx
rule exists.

674D-- --A

These models meet the California maximum oxides of nitrogen
(NOx) emissions requirements of 40 nanograms/joule or less as
shipped from the factory.

NOTE: Low NOx requirements apply only to natural gas
installations.

!

WARNING

CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in personal
injury or death.

The venting system is designed to ensure proper venting.
The flue hood assembly must be installed as indicted in this
section of the unit installation instructions.

Install the flue hood as follows:

1. This installation must conform with local building codes
and with the National Fuel Gas Code (NFGC) NFPA 54 /
ANSI Z223.1, (in Canada, CAN/CGA B149.1, and
B149.2) latest revision. Refer to Provincial and local
plumbing or wastewater codes and other applicable local
codes.

2. Remove flue hood from shipping location (inside the return
section of the blower compartment--see Fig. 8 and 9). Re­move the return duct cover to locate the flue hood. Place
flue hood assembly over flue panel. Orient screw holes in
flue hood with holes in the flue panel.

3. Secure flue hood to flue panel by inserting a single screw on
the top flange and the bottom flange of the hood.

Step 8 — Install Gas Piping

The gas supply pipe enters the unit through the access hole
provided. The gas connection to the unit is made to the 1/2--in.
(12.7 mm) FPT gas inlet on the gas valve.

Install a gas supply line that runs to the heating section. Refer to
Table 2 and the NFGC for gas pipe sizing. Do not use cast--iron
pipe. It is recommended that a black iron pipe is used. Check the

local utility for recommendations concerning existing lines. Size
gas supply piping for 0.5 IN. W.C. maximum pressure drop. Never
use pipe smaller than the 1/2--in. (12.7 mm) FPT gas inlet on the
unit gas valve.

For natural gas applications, the gas pressure at unit gas connection
must not be less than 4.0 IN. W.C. or greater than 13 IN. W.C.
while the unit is operating. For propane applications, the gas
pressure must not be less than 11.0 IN. W.C. or greater than 13 IN.
W.C. at the unit connection.

A 1/8-- in. (3.2 mm) NPT plugged tapping, accessible for test gauge
connection, must be installed immediately upstream of the gas
supply connection to the gas valve.

When installing the gas supply line, observe local codes pertaining
to gas pipe installations. Refer to the NFGC NFPA 54/ANSI
Z223.1 latest edition (in Canada, CAN/CGA B149.1).

NOTE: In the state of Massachusetts:

1. Gas supply connections MUST be performed by a licensed
plumber or gas fitter.

2. When flexible connectors are used, the maximum length
shall not exceed 36 in. (915 mm).

3. When lever handle type manual equipment shutoff valves
are used, they shall be T--handle valves.

4. The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.

In the absence of local building codes, adhere to the following
pertinent recommendations:

1. Avoid low spots in long runs of pipe. Grade all pipe 1/4 in.
(6.35 mm) for every 15 ft (4.6 m) of length to prevent traps.
Grade all horizontal runs downward to risers. Use risers to
connect to heating section and to meter.

2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate straps,
hangers, etc. Use a minimum of one hanger every 6 ft (1.8
m). For pipe sizes larger than 1/2 in., (12.7 mm) follow
recommendations of national codes.

3. Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.

4. Install sediment trap in riser leading to heating section (See
Fig. 7). This drip leg functions as a trap for dirt and
condensate.

5. Install an accessible, external, manual main shutoff valve in
gas supply pipe within 6 ft (1.8 m) of heating section.

6. Install ground--joint union close to heating section between
unit manual shutoff and external manual main shut--off
valve.

7. Pressure test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.

NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig. Pressure test the
gas supply piping system at pressures equal to or less than 0.5 psig.
The unit heating section must be isolated from the gas piping
system by closing the external main manual shutoff valve and
slightly opening the ground--joint union.

8

!

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury,
death and/or property damage.

--Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.

--Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections.

--Use proper length of pipe to avoid stress on gas control
manifold.

--If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at
furnace gas valve and extend a minimum of 2 in. (51 mm)
outside furnace casing.

been completed. Use a commercially available soap solution
made specifically for the detection of leaks (or method
specified by local codes and/or regulations).

IN

TEE

OUT

NIPPLE

--If codes allow a flexible connector, always use a new
connector. Do not use a connector which has previously

CAP

serviced another gas appliance.

8. Check for gas leaks at the field--installed and

Fig. 7 -- Sediment Trap

C99020

factory--installed gas lines after all piping connections have

Table 1 – Physical Data -- Unit 674D----A

UNIT SIZE 674D --- ---A 24040 24060 30040 30060 36060 36090 42060 42090

NOMINAL CAPACITY --- ton 2 2 2 --- 1 / 2 2 --- 1 / 2 3 3 3 --- 1 / 2 3 --- 1 / 2

SHIPPING WEIGHT --- lb.

COMPRESSORS Scroll

Quantity 1

REFRIGERANT (R --- 410A)

Quantity --- lb

REFRIGERANT METERING

Nominal Cooling Airflow--- (CFM)

Natural Gas Qty...Drill Size (Factory Installed)

Propane GasQty...Drill Size

HIGH --- PRESSURE SWITCH

LOW--- PRESSURE SWITCH

RETURN--- AIR FILTERS † }

*Based on altitude of 0 to 2000 ft (0 ---610 m).
{Required filter sizes shown are based on the larger of the AHRI (Air Conditioning, Heating and Refrigeration Institute) rated cooling airflow or the heating airflow

velocity of 300 ft/minute for high ---capacity type. Air filter pressure drop for non --- standard filters must not exceed 0.08 IN. W.C.
} If using accessory filter rack refer to filter rack installation instructions for correct filter size and quantity.

DEVICE

OUTDOOR ORIFICE

in. (qty)

(mm)

OUTDOOR COIL

Rows...Fins/in.
F a c e A r e a --- s q f t
OUTDOOR FAN

Nominal Cfm
Diameter--- in.

Motor Hp (Rpm)

INDOOR COIL

Rows...Fins/in.
F a c e A r e a --- s q f t

INDOOR BLOWER

S i z e --- i n .

M o t o r --- h p

FURNACE SECTION*

Burner Orifice

( p s i g ) C u t --- o u t

Reset (Auto)

L O S S --- O F --- C H A R G E /

(Liquid Line) (psig)

C u t --- o u t

Reset (auto)

Throwaway (in.)

(kg)

(kg)

(mm)

(mm)

(mm)

359
163

8.3

3.8

0.032 ( 2)

2...21

11.9

2000

24

610

1/5 (810)

3...17

3.7

800

10x10

254x254

1/2

2...44

2...55

20x20x1

508x508x25

.81

359
163

8.3

3.8

2...21

11.9

2000

24

610

1/5 (810)

3...17

3.7

800

10x10

254x254

1/2

2...38

2...53

373
169

10.2

4.6

0.035 ( 2)

2...21

11.9

2700

24

610

1/5 (810)

3...17

3.7

1000

10x10

254x254

1/2

2...44

2...55

20x24x1

508x610x25

373
169

10.2

4.6

I n d o o r --- T X V, O u td oo r --- A c c u r a t e r

.89

2...21

11.9

2700

24

610

1/5 (810)

3...17

3.7

1000

10x10

254x254

1/2

2...38

2...53

650 +/ ---15
420 +/ ---25

2 0 + / --- 5

45 +/ ---10

379
172

7.9

3.6

2...21

11.9

2700

24

610

1/5 (810)

3...17

3.7

1200

11x10

279x254

3/4

2...38

2...53

0.037 (2)
.94

379
172

7.9

3.6

2...21

11.9

2700

24

610

1/5 (810)

3...17

3.7

1200

11x10

279x254

3/4

3...38

3...53

610x762x25

24x30x1

461
209

10.0

4.5

0.038 ( Left)

0.040(Right)

2...21

13.6

3100

26

660

1/5 (810)

3...17

4.7

1400

11x10

279x254

3/4

2...38

2...53

.97/1.02

1/5 (810)

279x254

461
209

10.0

4.5

2...21

13.6

3100

26

660

3...17

4.7

1400

11x10

3/4

3...38

3...53

674D-- --A

9

Table 1 -- Physical Data -- Unit 674D----A (Cont’d)

NUMBER

OF

MANIFOLD

PRES

SURE

ORIFICES

UNIT SIZE 674D --- ---A 48090 48115 48130 60090 60115 60130

NOMINAL CAPACITY --- ton 4 4 4 5 5 5

OPERATING WEIGHT--- lb

COMPRESSORS Scroll

Quantity 1

REFRIGERANT (R --- 410A)

Quantity --- lb

REFRIGERANT METERING DEVICE TXV

OUTDOOR ORIFICE --- in. (qty)

OUTDOOR COIL

Rows...Fins --- in.
F a c e A r e a --- s q f t

OUTDOOR FAN

Nominal Cfm

Diameter--- in.

M o t o r H p --- R p m

INDOOR COIL
Rows...Fins --- in.
F a c e A r e a --- s q f t

INDOOR BLOWER

Nominal Cooling Airflow--- (CFM)

674D-- --A

Natural Gas Qty...Drill Size (Factory Installed)

*Based on altitude of 0 to 2000 ft (0 ---610 m).
{Required filter sizes shown are based on the larger of the AHRI (Air Conditioning, Heating and Refrigeration Institute) rated cooling airflow or the heating airflow

velocity of 300 ft/minute for high ---capacity type. Air filter pressure drop for non --- standard filters must not exceed 0.08 IN. W.C.
} If using accessory filter rack refer to filter rack installation instructions for correct filter size and quantity.

Propane GasQty...Drill Size

HIGH --- PRESSURE SWITCH (psig) Cut --- out

LOW--- PRESSURE SWITCH

S i z e --- i n .

M o t o r --- h p

FURNACE SECTION*

Burner Orifice

Reset (Auto)

L O S S --- O F --- C H A R G E /

(Liquid Line) (psig)

C u t --- o u t

Reset (auto)

RETURN--- AIR FILTERS †

Throwaway (in.)

(mm)

(kg)

(kg )

(mm)

(mm)

(mm)

482
219

2...21

13.6

3100

26

660

1/5 (810)

3...17

4.7

1600

11x10

279x254

1.0

3...38

3...53

482
219

9.6

4.4

0.046 (2)

1.2

2...21

13.6

3100

26

660

1/5 (810)

3...17

4.7

1600

11x10

279x254

1.0

3...33

3...51

482
219

2...21

13.6

3100

26

660

1/5 (810)

3...17

4.7

1600

11x10

279x254

1.0

3...31

3...49
650 +/ ---15
420 +/ ---25

2 0 + / --- 5

45 +/ ---10

24x36x1

(610x914x25)

507
230

2...21

17.5

3500

26

660

1/5 (810)

3...17

5.7

1850

11x10

279x254

1.0

3...38

3...53

507
230

12.3

5.6

0.052 (2)

1.3

2...21

17.5

3500

26

660

1/5 (810)

3...17

5.7

1850

11x10

279x254

1.0

3...33

3...51

507
230

2...21

17.5

3500

26

660

1/5 (810)

3...17

5.7

1850

11x10

279x254

1.0

3...31

3...49

Table 2 – Maximum Gas Flow Capacity*

NOMINAL

IRON
PIPE,

SIZE (IN.)

1/2 .622 175 120 97 82 73 66 61 57 53 50 44 40 — —
3/4 .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72

1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
1 --- 1 / 4 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280
1 --- 1 / 2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430

* Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5 ---IN. W.C. (based on a 0.60 specific gravity gas). Refer toTable2
and National Fire Protection Association NFPA 54/ANSI Z223.1.
† This length includes an ordinary number of fittings.

INTERNAL

DIAMETER

(IN.)

10

(3.1)20(6.1)30(9.1)40(12.2)50(15.2)60(18.3)70(21.3)80(24.4)90(27.4)

LENGTH OF PIPE, FT† (m)

100

(30.5)

125

(38.1)

150

(46.0)

175

(53.3)

Table 3 – Heating Inputs

HEATING INPUT

(BTUH)

GAS SUPPLY PRESSURE (IN. W.C.)

Natural{ Propane*{

Min Max Min Max Natural{ Propane*†

40,000 2 4.0 13.0 11.0 13.0 3.2∼3.8 10.0∼11.0
60,000 2 4.0 13.0 11.0 13.0 3.2∼3.8 10.0∼11.0

90,000 3 4.0 13.0 11.0 13.0 3.2∼3.8 10.0∼11.0
115,000 3 4.0 13.0 11.0 13.0 3.2∼3.8 10.0∼11.0
130,000 3 4.0 13.0 11.0 13.0 3.2∼3.8 10.0∼11.0

*When a unit is converted to propan e, differen t size orifices must be used. See separate, natural --- to ---propane conversion kit instructions.

{Based on altitudes from sea level to 2000 ft (610 m) above sea level. In U.S.A. for altitudes above 2000 ft (610 m), reduce input rating 4 percent for each addi-

tional 1000 ft (305 m) above sea level. In Canada, from 2000 ft (610 m) above sea level to 4500 ft (1372 m) above sea level, derate the unit 10 percent.

MANIFOLD PRESSURE

(IN. W.C.)

200

(61.0)

10

Step 9 — Install Duct Connections

The unit has duct flanges on the supply-- and return--air openings
on the side and bottom of the unit. For downshot applications, the
ductwork connects to the roof curb (See Fig. 2 and 3 for
connection sizes and locations).

Configuring Units for Downflow (V ertical) Discharge

!

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury
or death.

Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be more
than one disconnect switch.

1. Open all electrical disconnects before starting any service

work.

2. Remove horizontal (metal) duct covers to access vertical

(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)

WARNING

4. All units must have field-- supplied filters or accessory filter
rack installed in the return-- air side of the unit.
Recommended sizes for filters are shown in Table 1.

5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.

6. Adequately insulate and weatherproof all ductwork located
outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest issue
of Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
of America (ACCA) minimum installation standards for
heating and air conditioning systems. Secure all ducts to
building structure.

7. Flash, weatherproof, and vibration--isolate all openings in
building structure in accordance with local codes and good
building practices.

!

CAUTION

PROPERTY DAMAGE HAZARD

Failure to follow this caution may result in property damage.

Collect ALL screws that were removed. Do not leave screws
on rooftop as permanent damage to the roof may occur.

To remove downflow return and supply knockout covers, break
front and right side connecting tabs with a screwdriver and
hammer. Push cover down to break rear and left side tabs.

NOTE: These panels are held in place with tabs similar to an
electrical knockout. Reinstall horizontal duct covers (Fig. 8)
shipped on unit from factory. Insure openings are air and
watertight.

NOTE: The design and installation of the duct system must be in

accordance with the standards of the NFPA for installation of

nonresidence--type air conditioning and ventilating systems, NFPA

90A or residence--type, NFPA 90B; and/or local codes and

ordinances.

Adhere to the following criteria when selecting, sizing, and
installing the duct system:

1. Units are shipped for horizontal duct installation (by
removing duct covers).

2. Select and size ductwork, supply--air registers, and
return-- air grilles according to American Society of Heating,
Refrigeration and Air Conditioning Engineers (ASHRAE)
recommendations.

3. Use flexible transition between rigid ductwork and unit to
prevent transmission of vibration. The transition may be
screwed or bolted to duct flanges. Use suitable gaskets to
ensure weather tight and airtight seal.

Basepan
Downflow
(Vertical)
Supply
Knockout

Horizontal Duct Covers

Fig. 8 -- Supply and Return Duct Opening

A09061

Basepan
Downflow
(Vertical)
Return
Knockout

A09060

674D-- --A

11

Step 10 — Install Electrical Connections

!

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury
or death.

The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduitapprovedfor electricalground when
installed in accordance with NEC, NFPA 70 National Fire
Protection Association (latest edition) (in Canada, Canadian
Electrical Code CSA C22.1) and local electrical codes.

!

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to the unit
being installed.

1. Make all electrical connections in accordance with NEC

674D-- --A

NFPA 70 (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical
connections must be in accordance with CSA standard
C22.1 Canadian Electrical Code Part 1 and applicable
local codes. Refer to unit wiring diagram.

2. Use only copper conductor for connections between
field--supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.

3. Be sure that high--voltage power to unit is within
operating voltage range indicated on unit rating plate. On
3--phase units, ensure phases are balanced within 2
percent. Consult local power company for correction of
improper voltage and/or phase imbalance.

4. Insulate low-- voltage wires for highest voltage contained
within conduit when low--voltage control wires are in
same conduit as high--voltage wires.

5. Do not damage internal components when drilling
through any panel to mount electrical hardware, conduit,
etc.

High--Voltage Connections

When routing power leads into unit, use only copper wire between
disconnect and unit. The high voltage leads should be in a conduit
until they enter the duct panel; conduit termination at the duct
panel must be watertight.

The unit must have a separate electrical service with a
field--supplied, waterproof disconnect switch mounted at, or within
sight from, the unit. Refer to the unit rating plate, NEC and local
codes for maximum fuse/circuit breaker size and minimum circuit
amps (ampacity) for wire sizing.

The field-- supplied disconnect switch box may be mounted on the
unit over the high--voltage inlet hole when the standard power and
low-- voltage entry points are used (See Fig. 2 and 3 for acceptable
location).

NOTE: Field supplied disconnect switch box should be
positioned so that it does not cover up any of the unit gas
combustion supply air louvers.

See unit wiring label (Fig. 14 and 15) and Fig. 9 for reference
when making high voltage connections. Proceed as follows to
complete the high--voltage connections to the unit.

WARNING

CAUTION

Single phase units:

1. Run the high--voltage (L1, L2) and ground lead into the
control box.

2. Connect ground lead to chassis ground connection.

3. Locate the black and yellow wires connected to the line side
of the contactor.

4. Connect field L1 to black wire on connection 11 of the
compressor contactor.

5.ConnectfieldwireL2toyellowwireonconnection23of
the compressor contactor.

Three-- phase units:

1. Run the high--voltage (L1, L2, L3) and ground lead into the
control box.

2. Connect ground lead to chassis ground connection.

3. Locate the black and yellow wires connected to the line side
of the contactor.

4. Connect field L1 to black wire on connection 11 of the
compressor contactor.

5.ConnectfieldwireL3toyellowwireonconnection13of
the compressor contactor.

6. Connect field wire L2 to blue wire from compressor.

Special Procedures for 208--V Operation

!

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury
or death.

Make sure the power supply totheunit is switchedOFF before
making any wiring changes. Tag the disconnect switch with a
suitable warning label. With disconnect switch open, move
black wire from transformer (3/16 in.) terminal marked 230 to
terminal marked 200. This retaps transformer to primary
voltage of 208 vac.

!

WARNING

ELECTRICAL SHOCK AND EXPLOSION HAZARD

Failure to follow this warning could result in personal injury
or death.

Beforemaking any wiring changes,make sure the gassupply
is switched off first. Then switch off the power supply to the
unit and install lockout tag.

Control Voltage Connections

Do not use any type of power--stealing thermostat. Unit control
problems may result.

Use no. 18 American Wire Gage (AWG) color--coded, insulated
(35_C minimum) wires to make the control voltage connections
between the thermostat and the unit. If the thermostat is located
more than 100 ft (30.5 m) from the unit (as measured along the
control voltage wires), use no. 16 AWG color--coded, insulated
(35_C minimum) wires.

Locate the seven (eight on 3 -- phase) low voltage thermostat leads
in 24 volt splice box. See Fig. 9 for connection diagram. Run the
low--voltage leads from the thermostat, through the control wiring
inlet hole grommet (Fig. 2 and 3), and into the low-- voltage splice
box. Provide a drip loop before running wires through panel.
Secure and strain relief all wires so that they do not interfere with
operation of unit. A gray wire is standard on 3--phase unit for
connection to an economizer.

12

HIGH VOLTAGE
POWER LEADS
(SEE UNIT WIRING
LABEL)

CONTROL BOX

LOW-VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)

EQUIP GR

SPLICE BOX

FIELD-SUPPLIED
FUSED DISCONNECT

WHT(W1)

YEL(Y)

GRN(G)

RED(R)

BRN(C)

ORN(O)

BLU (DH)

GRA (Y2)

W

Y

G

R

C

O

DH

3-Phase
Only

POWER
SUPPLY

THERMOSTAT
(TYPICAL)

A09067

Fig. 9 -- High and Control--Voltage Connections

Balance Point Setting--Thermidistat or Hybrid
Thermostat

BALANCE POINT TEMPERATURE--The “balance point”
temperature is a setting which affects the operation of the heating
mode. This is a field--selected input temperature (range 5 to 55_F)
(--15to12_C) where the Thermidistat or dual fuel thermostat will
monitor outdoor air temperature and decide whether to enable or
disable the heat pump. If the outdoor temperature is above the
“balance point”, the heat pump will energize first to try to satisfy
the indoor temperature demand. If the heat pump does not make a
sufficient improvement within a reasonable time period (i.e. 15
minutes), then the gas furnace will come on to satisfy the indoor
temperature demand. If the outdoor temperature is below the
“balance point”, the heat pump will not be allowed to operate (i.e.
locked out), and the gas furnace will be used to satisfy the indoor
temperature. There are three separate concepts which are related to
selecting the final “balance point” temperature. Read each of the
following carefully to determine the best “balance point” in a
hybrid installation:

1. Capacity Balance Temperature: This is a point where the
heat pump cannot provide sufficient capacity to keep up
with the indoor temperature demand because of declining
outdoor temperature. At or below this point, the furnace is
needed to maintain proper indoor temperature.

2. Economic Balance Temperature: Above this point, the heat
pump is the most cost efficient to operate, and below this
point the furnace is the most cost efficient to operate. This
can be somewhat complicated to determine and it involves
knowing the cost of gas and electricity, as well as the
efficiency of the furnace and heat pump. For the most
economical operation, the heat pump should operate above
this temperature (assuming it has sufficient capacity) and the
furnace should operate below this temperature.

3. Comfort Balance Te mperature: When the heat pump is
operating below this point, the indoor supply air feels
uncomfortable (i.e. too cool). This is purely subjective and
will depend on the homeowner’s idea of comfort. Below
this temperature the gas furnace should operate in order to
satisfy the desire for indoor comfort.

Transformer Protection

The transformer is of the energy--limiting type. It is set to withstand
a 30--sec. overload or shorted secondary condition. If an overload
or short is present, correct overload condition and check for blown
fuse on gas control board or Interface Fan Board. Replace fuse as
required with correct size and rating.

PRE--START--UP

!

WARNING

FIRE,EXPLOSION, ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury,
death or property damage.

1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.

2. Do not operate compressor or provide any electric power
to unit unless compressor terminal cover is in place and
secured.

3. Do not remove compressor terminal cover until all
electrical sources are disconnected and tagged.

4. Relieve and recover all refrigerant from system before
touching or disturbing anything inside terminal box if
refrigerant leak is suspected around compressor
terminals.

5. Never attempt to repair soldered connection while
refrigerant system is under pressure.

6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure.
To remove a component, wear protective goggles and
proceed as follows:

a. Shut off electrical power to unit and install lockout

tag.

b. Relieve and reclaim all refrigerant from system

using both high-- and low--pressure ports.

c. Cut component connecting tubing with tubing

cutter and remove component from unit.

d. Carefully unsweat remaining tubing stubs when

necessary. Oil can ignite when exposed to torch
flame.

Proceed as follows to inspect and prepare the unit for initial
start--up:

1. Remove access panels (see Fig. 18).

2. Read and follow instructions on all WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with, unit.

3. Make the following inspections:

a. Inspect for shipping and handling damages such as

broken lines, loose parts, disconnected wires, etc.

b. Inspect for oil at all refrigerant tubing connections and

on unit base. Detecting oil generally indicates a
refrigerant leak.

c. Leak test all refrigerant tubing connections using

electronic leak detector, halide torch, or liquid-- soap
solution. If a refrigerant leak is detected, see the Check
for Refrigerant Leaks section.

d. Inspect all field-- and factory--wiring connections. Be

sure that connections are completed and tight.

e. Ensure wires do not touch refrigerant tubing or sharp

sheet metal edges.

f. Inspect coil fins. If damaged during shipping and

handling, carefully straighten fins with a fin comb.

!

WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal injury,
death or property damage.

Do not purgegas supply intothe combustionchamber.Do not
use a match or other open flame to check for gas leaks. Use a
commercially available soap solution made specifically for
the detection of leaks to check all connections.

674D-- --A

13

4. Verify the following conditions:

a. Make sure gas line is free of air. Before lighting the unit

for the first time, perform the following with the gas
valve in the “OFF” position:

NOTE: If the gas supply pipe was not purged before connecting
the unit, it will be full of air. It is recommended that the ground
joint union be loosened, and the supply line be allowed to purge
until the odor of gas is detected. Never purge gas lines into a
combustion chamber. Immediately upon detection of gas odor,
retighten the union. Allow 5 minutes to elapse, then light unit.

b. Make sure that condenser-- fan blade is correctly

positioned in fan orifice. Leading edge of condenser-- fan
blade should be 1/2 in. (12 mm) maximum from fan
orifice.

c. Make sure that air filter(s) is in place.

d. Make sure that condensate drain trap is filled with water

to ensure proper drainage.

e. Make sure that all tools and miscellaneous loose parts

have been removed.

START--UP

Step 1 — Check for Refrigerant Leaks

674D-- --A

Proceed as follows to locate and repair a refrigerant leak and to
charge the unit:

1. Locate leak and make sure that refrigerant system pressure
has been relieved and reclaimed from both high-- and
low-- pressure ports.

2. Repair leak following Refrigerant Service procedures.

NOTE: Install a bi--flow filter drier whenever the system has been
opened for repair.

3. Add a small charge of R --410A refrigerant vapor to system
and leak--test unit.

4. Recover refrigerant from refrigerant system and evacuate to
500 microns if no additional leaks are not found.

5. Charge unit with Puron (R--410A) refrigerant, using an
electronic scale. Refer to unit rating plate for required
charge.

Step 2 — Unit Sequence of Operation

674D----A Sequence of Operation

a. CONTINUOUS FAN

(1.) Thermostat closes circuit R to G energizing the

blower motor for continuous fan.

b. COOLING MODE

(1.) If indoor temperature is above temperature set

point thermostat closes circuits R to G, R to Y and
R to O--The unit delivers cooling airflow.

c. HEAT PUMP HEATING MODE

Outdoor temperature above balance point setpoint of
thermostat.

(1.) On a call for heating, terminals “Y” and “G“ of the

Hybrid thermostat are energized. The “Y“ signal is
sent to the Defrost Board (DB) terminal “Y”. The
DB has a built in five minute anti--short cycle timer
which will not allow the compressor to restart
before the time delay has expired.

(2.) “T2” energizes the compressor contactor via the

High Pressure Switch (HPS) and Low Pressure
Switch (LPS). The compressor and outdoor fan
start. Thermostat “G” energizes the Interface Fan
Board terminal “G”. The blower motor is energized
through contacts of the IFB.

(3.) When the thermostat removes the “Y” and “G”

calls, the compressor contactor and outdoor fan are

Heating Sequence of Operation

(See Fig. 14 and 15 and unit wiring label.)
On a call for heating, terminal W of the thermostat is energized,

starting the induced--draft motor. When the pressure switch senses
that the induced--draft motor is moving sufficient combustion air,
the burner sequence begins. This function is performed by the
integrated gas unit controller (IGC). The indoor (evaporator)--fan
motor is energized 45 sec after flame is established. When the
thermostat is satisfied and W is de--energized, the burners stop
firing and the indoor (evaporator) fan motor shuts off after a
45-- sec time--off delay. Please note that the IGC has the capability
to automatically reduce the indoor fan motor on delay and increase
the indoor fan motor off delay in the event of high duct static
and/or partially-- clogged filter.

NOTE: An LED (light--emitting diode) indicator is provided on
the control board to monitor operation. The control board is
located by removing the burner access panel (see Fig. 18). During
normal operation, the LED is continuously on.

Step 3 — Start--up Heating and Make Adjust­ments

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to the unit
being installed.

Completethe required procedures given in the Pre--Start-- Up
section before starting the unit. Do not jumper any safety
devices when operating the unit.

Complete the required procedures given in the Pre--Start--Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Make sure that burner orifices are
properly aligned. Unstable operation my occur when the burner
orifices in the manifold are misaligned.

Follow the lighting instructions on the heating section operation
label (located on the inside of the control access panel) to start the
heating section.

NOTE: Make sure that gas supply has been purged, and that all
gas piping has been checked for leaks.

Pipe Plug

de--energized. The evaporator motor is de--ener­gized after a 90 sec. delay.

d. GAS HEATING MODE

Outdoor temperature below balance point setpoint of
thermostat.

!

CAUTION

Manifold

Fig. 10 -- Burner Assembly

A07679

14

BURNER FLAME

BURNER

MANIFOLD

C99021

Fig. 11 -- Monoport Burner

Check Heating Control

Start and check the unit for proper heating control operation as
follows (see furnace lighting instructions located on the inside of
the control access panel):

1. Place room thermostat SYSTEM switch in the HEAT
position and the fan switch is placed in AUTO position.

2. Set the heating temperature control of the thermostat above
room temperature.

3. The induced--draft motor will start.

4. On a call for heating, the main burner should light within 5
sec. of the spark being energized. If the burners do not light,
there is a 22--sec. delay before another 5-- sec. try. If the
burners still do not light, this sequence is repeated. If the
burners do not light within 15 minutes from the initial call
for heat, there is a lockout. To reset the control, break the
24--v power to W.

5. The evaporator fan will turn on 45 sec. after the flame has
been established. The evaporator fan will turn off 45 sec.
after the thermostat has been satisfied. Please note that the
integrated gas unit controller (IGC) has the capability to
automatically reduce the evaporator “ON” delay and in­crease the evaporator “OFF” delay in the event of high duct
static and/or partially--clogged filter .

Check Gas Input

Check gas input and manifold pressure after unit start--up (See
Table 3). If adjustment is required proceed as follows:

S The rated gas inputs shown in Table 3 are for altitudes from sea

level to 2000 ft (610 m) above sea level. These inputs are based

3

on natural gas with a heating value of 1025 Btu/ft

specific gravity, or propane gas with a heating value of 2500

3

at 1.5 specific gravity.

Btu/ft

IN THE U.S.A.:

The input rating for altitudes above 2,000 ft (610 m) must be
reduced by 4% for each 1,000 ft (305 m) above sea level.

For installations below 2,000 ft (610 m), refer to the unit rating
plate.

For installations above 2,000 ft (610 m) multiply the input by on
the rating plate by the derate multiplier in Table 4 for correct input
rate.

at 0.60

Table 4 – Altitude Derate Multiplier for U.S.A.*

ALTITUDE FT (M) P ERCENT O F DERATE

0--- 2000
(0--- 610)

2001--- 3000*

(610--- 914)

3001--- 4000

(315--- 1219)

4001--- 5000

(1220--- 1524)

5001--- 6000

(1524--- 1829)

6001--- 7000

(1829--- 2134)

7001--- 8000

(2134--- 2438)

8001--- 9000

(2439--- 2743)

9001--- 10,000
(2744--- 3048)

*In Canada see Canadian Altitude Adjustment.
{Derate multiplier factors are based on midpoint altitude for altitude range.

0 1.00

8 --- 1 2 0.90

12--- 16 0.86

16--- 20 0.82

20--- 24 0.78

24--- 28 0.74

28--- 32 0.70

32--- 36 0.66

36--- 40 0.62

DERATE MULTIPLIER

FACT OR{

IN CANADA:
The input rating for altitudes from 2,000 to 4,500 ft (610 m to

1372 m) above sea level must be derated 10% by an authorized
Gas Conversion Station or Dealer.

EXAMPLE:
90,000 Btu/hr Input Furnace Installed at 4300 ft (1311 m).

Furnace Input Rate at
Sea Level

90,000 X 0.90 = 81,000

XDerateMultiplier

Facto r

= Furnace Input Rate at

Installation Altitude

When the gas supply being used has a different heating value or
specific gravity, refer to national and local codes, or contact your
distributor to determine the required orifice size.

!

CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in reduced unit
and/or component life.

Do No t redrill an orifice. Improper drilling (burrs,
out--of--round holes, etc.) can cause excessive burner noise
and misdirection of burner flame. If orifice hole appears
damaged or it is suspected to have been redrilled, check
orifice hole with a numbered drill bit of correct size.

Adjust Gas Input

The gas input to the unit is determined by measuring the gas flow
at the meter or by measuring the manifold pressure. Measuring the
gas flow at the meter is recommended for natural gas units. The
manifold pressure must be measured to determine the input of
propane gas units.

Measure Gas Flow (Natural Gas Units)

Minor adjustment to the gas flow can be made by changing the
manifold pressure. The manifold pressure must be maintained
between 3.2 and 3.8 IN. W.C.

If larger adjustments are required, change main burner orifices
following the recommendations of national and local codes.

NOTE: All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.

Proceed as follows:

1. Turn off gas supply to unit.

2. Remove pipe plug on manifold (See Fig. 10) and connect
manometer. Turn on gas supply to unit.

3. Record number of seconds for gas meter test dial to make
one revolution.

674D-- --A

15

4. Divide number of seconds in Step 3 into 3600 (number of
seconds in one hr).

5. Multiply result of Step 4 by the number of cubic feet (cu ft)
shown for one revolution of test dial to obtain cubic feet (cu
ft) of gas flow per hour.

6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 3 (Consult the local gas
supplier if the heating value of gas is not known).

EXAMPLE: Assume that the size of test dial is 1 cu ft, one
revolution takes 32 sec, and the heating value of the gas is 1050

3

. Proceed as follows:

Btu/ft

1. 32 sec. to complete one revolution.

2. 3600 ÷ 32 = 112.5.

3. 112.5x1=112.5ft

3

of gas flow/hr.

4. 112.5 x 1050 = 118,125 Btuh input.

If the desired gas input is 115,000 Btuh, only a minor change in the
manifold pressure is required.

Observe manifold pressure and proceed as follows to adjust gas
input:

1. Remove regulator cover screw over plastic adjustment
screw on gas valve (See Fig. 12).

674D-- --A

2. Turn plastic adjustment screw clockwise to increase gas
input, or turn plastic adjustment screw counterclockwise to
decrease input (See Fig. 12). Manifold pressure must be
between 3.2 and 3.8 IN. W.C.

REGULATOR
COVER SCREW

PLASTIC

ADJUSTMENT

ON/OFF SWITCH

INLET
PRESSURE TAP

SCREW

REGULATOR SPRING
(PROPANE - WHITE)
(

NATURAL - SILVER)

GAS PRESSURE
REGULATOR
ADJUSTMENT

MANIFOLD
PRESSURE TAP

A07751

Fig. 12 -- Single--Stage Gas Valve

!

WARNING

FIRE AND UNIT DAMAGE HAZARD

Failure to follow this warning could result in personal
injury or death and/or property damage.

Unsafe operation of the unit may result if manifold pressure
is outside this range.

3. Replace regulator cover screw on gas valve (See Fig. 12).

4. Turn off gas supply to unit. Remove manometer from
pressure tap and replace pipe plug on gas valve. (See Fig.

10.) Turn on gas to unit and check for leaks.

Measure Manifold Pressure (Propane Units)

Refer to propane kit installation instructions for properly checking
gas input.

NOTE: For installations below 2,000 ft (610 m), refer to the unit

the same for each burner. Propane will have blue flame (See Fig.

11). Refer to the Maintenance section for information on burner
removal.

Normal Operation

An LED (light--emitting diode) indicator is provided on the
integrated gas unit controller (IGC) to monitor operation. The IGC
is located by removing the control access panel (see Fig. 18).
During normal operation, the LED is continuously on (See Table 5
for error codes).

Airflow and Temperature Rise

The heating section for each size unit is designed and approved for
heating operation within the temperature--rise range stamped on the
unit rating plate.

Table 10 shows the approved temperature rise range for each
heating input, and the air delivery cfm at various temperature rises
for a given external static pressure. The heating operation airflow
must produce a temperature rise that falls within the approved
range.

Refer to Indoor Airflow and Airflow Adjustments section to adjust
heating airflow when required.

Limit Switches

Normally closed limit switch (LS) completes the control circuit.
Should the leaving--air temperature rise above the maximum
allowable temperature, the limit switch opens and the control
circuit “breaks.” Any interruption in the control circuit instantly
closes the gas valve and stops gas flow to the burners. The blower
motor continues to run until LS resets.

When the air temperature at the limit switch drops to the
low-- temperature setting of the limit switch, the switch closes and
completes the control circuit. The direct--spark ignition system
cycles and the unit returns to normal heating operation.

Table 5 – LED Indications

STATUS CODE LED INDICATION

Normal Operation

No Power or Hardware Failure Off

Limit Switch Fault 2 Flashes

Flame Sense Fault 3 Flashes

Four Consecutive Limit Switch Faults 4 Flashes

Ignition Lockout Fault 5 Flashes
Pressure Switch Fault 6 Flashes

Rollout Switch Fault 7 Flashes

Internal Control Fault 8 Flashes

Temporary 1 hr auto reset

NOTES:

1.This code indicates an internal processor fault that will reset itself in one
hr. Fault can be caused by stray RF signals in the structure or nearby. Th is
is a UL requirement.

2. LED indicates acceptable operation. Do not change ignition control
board.

3. When W is energized the burners will remain on for a minimum of 60 sec.

4.IfmorethanoneerrormodeexiststheywillbedisplayedontheLEDin
sequence.

2

1

On

9 Flashes

Rollout Switch

The function of the rollout switch is to close the main gas valve in
the event of flame rollout. The switch is located above the main
burners. When the temperature at the rollout switch reaches the
maximum allowable temperature, the control circuit trips, closing
the gas valve and stopping gas flow to the burners. The indoor
(evaporator) fan motor (IFM) and induced draft motor continue to
run until switch is reset. The IGC LED will display FAULT CODE

7.
rating plate for proper propane conversion kit. For installations
above 2,000 ft (610 m), contact your distributor for proper propane
conversion kit.

Check Burner Flame

With control access panel (see Fig. 18) removed, observe the unit
heating operation. Watch the burner flames to see if they are light
blue and soft in appearance, and that the flames are approximately

16

Step 4 — Start--up Cooling and Make Adjust­ments

Complete the required procedures given in the Pre--Start--Up
section before starting the unit. Do not jumper any safety devices
when operating the unit. Do not operate the compressor when the
outdoor temperature is below 40°F(4.4°C) (unless accessory
low--ambient kit is installed). Do not rapid--cycle the compressor.
Allow 5 minutes between on cycles to prevent compressor damage.

Checking Cooling Control Operation

Start and check the unit for proper cooling control operation as
follows:

1. Place room thermostat SYSTEM switch in OFF position.
Observe that blower motor starts wh en FAN switch is
placed in ON position and shuts down when FAN switch is
placed in AUTO position.

2. Place SYSTEM switch in COOL position and FAN switch
in AUTO position. Set cooling control below room
temperature. Observe that compressor, condenser fan, and
evaporator blower motors start. Observe that cooling cycle
shuts down when control setting is satisfied. The evaporator
fan will continue to run for 90 sec.

IMPORTANT: Three--phase, scroll compressors units are
direction oriented. Unit must be checked to ensure proper
compressor 3--phase power lead orientation. If not corrected within
5 minutes, the internal protector will shut off the compressor. The
3--phase power leads to the unit must be reversed to correct
rotation. When turning backwards, the difference between
compressor suction and discharge pressures will be near zero.

Checking and Adjusting Refrigerant Charge

The refrigerant system is fully charged with PuronR (R--410A)
refrigerant and is tested and factory sealed. Allow system to operate
a minimum of 15 minutes before checking or adjusting charge.

NOTE: Adjustment of the refrigerant charge is not required unless
the unit is suspected of not having the proper PuronR (R--410A)
charge.

The charging label and the tables shown refer to system
temperatures and pressures in cooling mode only. A refrigerant
charging label is attached to the inside of the compressor access
panel (see Fig. 18). The chart includes the required liquid line
temperature at given discharge line pressures and outdoor ambient
temperatures.

An accurate thermocouple-- or thermistor--type thermometer, and a
gauge manifold are required when using the subcooling charging
method for evaluating the unit charge. Do not use mercury or small
dial--type thermometers because they are not adequate for this type
of measurement.

!

UNIT DAMAGE HAZARD

Failure to follow this caution may result in unit damage.

When evaluating the refrigerant charge, an indicated
adjustment to the specified factory charge must always be
very minimal. If a substantial adjustment is indicated, an
abnormal condition exists somewhere in the cooling system,
such as insufficient airflow across either coil or both coils.

CAUTION

Proceed as follows:

1. Remove caps from low-- and high--pressure service fittings.

2. Using hoses with valve core depressors, attach low-- and
high--pressure gauge hoses to low-- and high--pressure
service fittings, respectively.

3. Start unit in Cooling Mode and let unit run until system
pressures stabilize.

4. Measure and record the following:

a. Outdoor ambient-- air temperature (°F[°C] db).

b. Liquid line temperature (°F[°C]).

c. Discharge (high--side) pressure (psig).

d. Suction (low--side) pressure (psig) (for reference only).

5. Using “Cooling Charging Charts,” compare outdoor--air
temperature(°F[°C] db) with the discharge line pressure
(psig) to determine desired system operating liquid line
temperature (See Fig. 16).

6. Compare actual liquid line temperature with desired liquid
line temperature. Using a tolerance of ± 2°F(±1.1°C), add
refrigerant if actual temperature is more than 2°F(1.1°C)
higher than proper liquid line temperature, or remove
refrigerant if actual temperature is more than 2°F(1.1°C)
lower than required liquid line temperature.

NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to the Check for Refrigerant Leaks section.

Indoor Airflow and Airflow Adjustments

!

CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in unit damage.

For cooling operation, the recommended airflow is 350 to
450 cfm for each 12,000 Btuh of rated cooling capacity. For
heating operation, the airflow must produce a temperature
rise that falls within the range stamped on the unit rating
plate.

NOTE: Be sure that all supply--and return--air grilles are open,
free from obstructions, and adjusted properly.

!

WARNING

ELECTRICAL SHOCK AND EXPLOSION HAZARD

Failure to follow this warning could result in personal
injury or death.

Before making any indoor wiring adjustments, shut off gas
supply. Then disconnect electrical power to the unit and
install lockout tag before changing blower speed.

This unit has independent fan speeds for gas heating and cooling.
In addition, this unit has the field-selectable capability to run two
different cooling fan speeds: A normal cooling fan speed (350~400
CFM/Ton) and an enhanced dehumidification fan speed (As low as
320 CFM/Ton) for use with either a dehumidistat or a thermostat
that supports dehumidification.

This unit is factory-set up for use with a single cooling fan speed.
The cooling speed is marked “LOW” on the interface fan board
(IFB) (See Fig. 13). The factory-shipped settings are noted in
Table 10. There are 3 additional speed tap wires available for use
in either gas heating or cooling (For color coding on the indoor fan
motor leads, see Table 6). The additional 3 speed tap wires are
shipped loose with vinyl caps and are located in the control box,
near the interface fan board (IFB) (See Fig. 13).

674D-- --A

17

Gas Heating Fan Speed Set-up

To change the gas heating speed:

1. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding). Table 10 shows the
temperature rise associated with each fan speed for a given
static pressure. Make sure that the speed chosen delivers a
temperature rise within the rise range listed on the unit
rating plate.

2. Remove the current speed tap wire from the “GAS HEAT”
terminal on the interface fan board (IFB) (Fig.14) and place
vinyl cap over the connector on the wire.

3. Connect the desired speed tap wire to the “GAS HEAT”
terminal on the interface fan board (IFB).

Single Cooling Fan Speed Set-up (Dehumidification
feature not

To change cooling speed:

1. Remove the vinyl cap off of the desired speed tap wire

674D-- --A

2. Remove the current speed tap wire from the “LOW”

3. Connect the desired speed tap wire to the “LOW” terminal

used)

(Refer to Table 6 for color coding). Add the wet coil
pressure drop in Table 8 to the system static to determine the
correct cooling airflow speed in Table 10 that will deliver
the nominal cooling airflow as listed in Table 1 for each
size.

terminal on the interface fan board (IFB) (See Fig. 13) and
place vinyl cap over the connector on the wire.

5. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding) for the dehumidification
cooling fan speed and place desired speed tap wire on the
“LOW” connection on the interface board (IFB). Verify
that static pressure is in the acceptable range for the speed
tap to be used for dehumidification cooling.

6. Use any spare vinyl plugs to cap any unused speed tap
wires.

Continuous Fan Operation

When the DEHUM feature is not used, the continuous fan speed
will be the same as cooling fan speed. When the DEHUM feature
is used, the continuous fan will operate on IFB “LOW” speed
when the DH control lead is not energized, or IFB “HIGH” speed
when the DH lead is energized (see Fig. 13).

NOTE: For heat pump operation, the recommended airflow is 350
to 450 CFM for each 12,000 Btuh of rated cooling capacity.

Table 6 – Color Coding for Indoor Fan Motor Leads

Black = High Speed

Orange = Med--- High Speed

Red=MedSpeed

P i n k = M e d --- Lo w S p e ed

Blue = Low Speed

GAS
HEAT

QC6 QC7 QC4 QC3

K2 K1

COMLOWHIGH

DCR QCR

on the interface fan board (IFB).

Two Cooling Fan Speeds Set-up (Dehumidification
feature

IMPORTANT: Dehumidification control must open control

circuit on humidity rise above set point.

Use of the dehumidification cooling fan speed requires use of
either a 24 VAC dehumidistat or a thermostat which includes
control of a 24 VAC dehumidistat connection. In either case, the
dehumidification control must open the control circuit on humidity
rise above the dehumidification set point. Dehumidification
controls are available with the reverse logic; these must not be
used.

used)

1. Remove fan speed tap wire from the “LOW” terminal on
the interface fan board (IFB) (See Fig. 13).

2. Determine correct normal cooling fan speed for unit and
application. Add the wet coil pressure drop in Table 8 to
the system static to determine the correct cooling airflow
speed in Table 10 that will deliver the nominal cooling
airflow as listed in Table 1 for each size.

3. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding) for the normal cooling
fan speed and place desired speed tap wire on “HIGH” on
the interface board.

R9 AB A15

U1

R3 R5 R6

P2

JW1

Y2/ Y1/

W2

Q1R1LC8RL3

JM6

Q3

G1

G2

C3

P1

GCR

YDH

SDL

RI0

C9

C4

D4D6C2OILL

A7

D3D5

P3

JW7

SSTZ-8

C7

R2

QCB

Y

YRUC24VAC

Fig. 13 -- Interface Fan Board (IFB)

JM5

JW3

D2

RI DL

R4 RL4

JW2

CDM/C

C

QC1

RI2

24VAC/R

3 AMP

F1

C0

JW4

A09058

4. Refer to airflow tables (Table 10) to determine allowable
speeds for the dehumidification cooling fan speed. In Table
10, speeds that are not allowed for dehumidification cooling
are shaded.

18

FILTER SIZE

in. (mm)

20X20X1

(508X508X25)

20X24X1

(508X610x25 )

24X30X1

(610X762x25)

24X36X1

(610X914X25)

Table 7 – Filter Pressure Drop Table (IN. W.C.)

CFM

500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300

0.05 0.07 0.08 0.10 0.12 0.13 0.14 0.15 — — — — — — — — — — —

— — — — 0.09 0.10 0.11 0.13 0.14 0.15 0.16 — — — — — — — —

— — — 0.04 0.05 0.06 0.07 0.07 0.08 0.09 0.10 — — — — — — — —

— — — — — — — 0.06 0.07 0.07 0.08 0.09 0.09 0.10 0.11 0.12 0.13 0.14 0.14

Table 8 – 674D-- -- A Wet Coil Pressure Drop (IN. W.C.)

Unit Size

24 0.06 0.07 0.08 0.09 0.10
30 0.12 0.15 0.19 0.23 0.27
36 0.07 0.11 0.18 0.26 0.35
42 0.04 0.07 0.10 0.15 0.21
48 0.11 0.14 0.17 0.22 0.28
60 0.10 0.17 0.23 0.31 0.36

500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

Standard CFM (S.C.F.M)

Table 9 – Wet Coil Air Delivery (CFM) -- Downflow -- High Speed with 1--in. (25 mm) Filter and Economizer

UNIT SIZE

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
36 1333 1289 1256 1214 1152 1118 1076 1035 997 950
42 1612 1569 1527 1481 1451 1393 1351 1317 1278 1242
48 2166 2085 2002 1919 1798 1709 1582 1467 1270 988
60 2298 2239 2180 2110 2044 1951 1862 1777 1697 1591

EXTERNAL STATIC PRESSURE (IN. W.C.)

Table 10 – Dry Coil Air Delivery* -- Horizontal and Downflow Discharge -- Unit 674D----A24 -- 60

UNIT

674D(N,P,E)WA24040

674D(N,P,E)WA24060

HEATING

RISE RANGE

30 --- 60oF

o

( 1 7 --- 3 3

( 1 4 --- 3 1

25 --- 55oF

C)

o

C)

MOTOR

SPEED

Low Blue

M e d --- L o w Pink

Medium

M e d ---

High

High Black

Low Blue

M e d --- L o w Pink

Medium

M e d --- H i g h Orange

High

WIRE

COLOR

2

Red

Orange

1

2

Red

1

Black

CFM 754 650 538 429 --- --- --- --- --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 851 777 675 591 475 --- --- --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 941 851 774 684 576 479 --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1009 917 840 759 667 577 447 --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1241 1167 1111 1036 969 881 818 731 640

Heating

Rise (

Heating

Rise (

CFM 754 650 538 429 --- --- --- --- --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 851 777 675 591 475 --- --- --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 941 851 774 684 576 479 --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1009 917 840 759 667 577 447 --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1241 1167 1111 1036 969 881 818 731 640

Heating

Rise (

Heating

Rise (

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

40 46 56 NA NA NA NA NA NA

o

F)

22 26 31 NA NA NA NA NA NA

o

C)

36 39 45 51 NA NA NA NA NA

o

F)

20 22 25 28 NA NA NA NA NA

o

C)

32 36 39 44 52 NA NA NA NA

o

F)

18 20 22 25 29 NA NA NA NA

o

C)

30 33 36 40 45 52 NA NA NA

o

F)

17 18 20 22 25 29 NA NA NA

o

C)

NA NA NA NA 31 34 37 41 47

o

F)

NA NA NA NA 17 19 21 23 26

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

52 NA NA NA NA NA NA NA NA

o

F)

29 NA NA NA NA NA NA NA NA

o

C)

47 52 NA NA NA NA NA NA NA

o

F)

26 29 NA NA NA NA NA NA NA

o

C)

44 48 53 NA NA NA NA NA NA

o

F)

24 27 29 NA NA NA NA NA NA

o

C)

36 38 40 43 46 50 54 NA NA

o

F)

20 21 22 24 25 28 30 NA NA

o

C)

EXTERNAL STATIC PRESSURE (IN. W.C.)

674D-- --A

19

Table 10 (cont) -- Dry Coil Air Delivery* -- Horizontal and Downflow Discharge -- Unit 674D----A24--60

UNIT

674D(N,P,E)WA30040

HEATING

RISE RANGE

30 --- 60oF
( 1 7 --- 3 3

674D-- --A

674D(N,P,E)WA30060

674D(N,P,E)WA36060

25 --- 55oF

( 1 4 --- 3 1

25 --- 55oF

( 1 4 --- 3 1

o

C)

o

C)

o

C)

MOTOR

SPEED

WIRE

COLOR

Low Blue

M e d ---

Low

1

Pink

Medium Red

M e d --­High

Orange

2

High Black

Low Blue

M e d ---

Low

Pink

Medium Red

M e d --­High

High

Low

M e d ---

Low

Medium

M e d ---

High

Orange

2

1

Black

1

Blue

Pink

2

Red

Orange

High Black

CFM 741 638 547 415 --- --- --- --- --- --- --- --- --- ---

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Heating

Rise (

Heating

Rise (

CFM 973 887 823 733 665 538 451 --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1088 1023 954 881 800 723 658 563 461

Heating

Rise (

Heating

Rise (

CFM 1140 1064 996 915 840 758 687 564 480

Heating

Rise (

Heating

Rise (

CFM 1202 1140 1082 1015 961 881 810 732 631

Heating

Rise (

Heating

Rise (

CFM 741 638 547 415 --- --- --- --- --- --- --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 973 887 823 733 665 538 451 --- --- --- ---

Heating

Rise (

Heating

Rise (

CFM 1088 1023 954 881 800 723 658 563 461

Heating

Rise (

Heating

Rise (

CFM 1140 1064 996 915 840 758 687 564 480

Heating

Rise (

Heating

Rise (

CFM 1202 1140 1082 1015 961 881 810 732 631

Heating

Rise (

Heating

Rise (

CFM 1234 1168 1093 1021 961 894 825 759 687

Heating

Rise (

Heating

Rise (

CFM 1290 1223 1154 1090 1027 977 894 828 762

Heating

Rise (

Heating

Rise (

CFM 1354 1290 1226 1158 1102 1046 981 918 843

Heating

Rise (

Heating

Rise (

CFM 1606 1546 1489 1430 1371 1316 1258 1208 1140

Heating

Rise (

Heating

Rise (

CFM 1630 1580 1517 1463 1407 1339 1277 1210 1131

Heating

Rise (

Heating

Rise (

41 47 55 NA NA NA NA NA NA

o

F)

23 26 31 NA NA NA NA NA NA

o

C)

31 34 37 41 45 56 NA NA NA

o

F)

17 19 20 23 25 31 NA NA NA

o

C)

NA 30 32 34 38 42 46 54 NA

o

F)

NA 16 18 19 21 23 26 30 NA

o

C)

NA NA 30 33 36 40 44 54 NA

o

F)

NA NA 17 18 20 22 24 30 NA

o

C)

NA NA NA 30 31 34 37 41 48

o

F)

NA NA NA 17 17 19 21 23 27

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

46 50 54 NA NA NA NA NA NA

o

F)

25 28 30 NA NA NA NA NA NA

o

C)

41 43 47 50 NA NA NA NA NA

o

F)

23 24 26 28 NA NA NA NA NA

o

C)

39 42 45 49 53 NA NA NA NA

o

F)

22 23 25 27 29 NA NA NA NA

o

C)

37 39 41 44 46 50 55 NA NA

o

F)

21 22 23 24 26 28 30 NA NA

o

C)

36 38 41 44 46 50 54 NA NA

o

F)

20 21 23 24 26 28 30 NA NA

o

C)

34 36 39 41 43 45 50 54 NA

o

F)

19 20 21 23 24 25 28 30 NA

o

C)

33 34 36 38 40 42 45 48 53

o

F)

18 19 20 21 22 24 25 27 29

o

C)

28 29 30 31 32 34 35 37 39

o

F)

15 16 17 17 18 19 20 20 22

o

C)

27 28 29 30 32 33 35 37 39

o

F)

15 16 16 17 18 18 19 20 22

o

C)

EXTERNAL STATIC PRESSURE (IN. W.C.)

20

Table 10 (cont) -- Dry Coil Air Delivery* -- Horizontal and Downflow Discharge -- Unit 674D----A24--60

UNIT

674D(N,P,E)WA36090

674D(N,P,E)WA42060

674D(N,P,E)WA42090

HEATING

RISE RANGE

35 --- 65oF

( 1 9 --- 3 6

25 --- 55oF

( 1 4 --- 3 1

35 --- 65oF

( 1 9 --- 3 6

MOTOR

SPEED

M e d --- L o w Pink

o

Medium

C)

M e d --- H i g h Orange

M e d --- L o w Pink

C)

Medium Red

o

M e d --- L o w Pink

o

Medium

C)

WIRE

COLOR

Low Blue

2

Red

1

High

Low

M e d ---

High

1

Black

Blue

Orange

2

High Black

Low Blue

1

Red

M e d ---

High

Orange

2

High Black

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

EXTERNAL STATIC PRESSURE (IN. W.C.)

CFM 1234 1168 1093 1021 961 894 825 759 687

Heating

Rise (

Heating

Rise (

CFM 1290 1223 1154 1090 1027 977 894 828 762

Heating

Rise (

Heating

Rise (

CFM 1354 1290 1226 1158 1102 1046 981 918 843

Heating

Rise (

Heating

Rise (

CFM 1606 1546 1489 1430 1371 1316 1258 1208 1140

Heating

Rise (

Heating

Rise (

CFM 1630 1580 1517 1463 1407 1339 1277 1210 1131

Heating

Rise (

Heating

Rise (

CFM 1295 1234 1182 1126 1075 1016 955 898 857

Heating

Rise (

Heating

Rise (

CFM 1345 1282 1235 1194 1140 1095 1027 974 921

Heating

Rise (

Heating

Rise (

CFM 1505 1452 1413 1358 1323 1282 1234 1169 1130

Heating

Rise (

Heating

Rise (

CFM 1545 1492 1449 1411 1362 1313 1278 1231 1188

Heating

Rise (

Heating

Rise (

CFM 1705 1643 1607 1568 1518 1483 1448 1404 1360

Heating

Rise (

Heating

Rise (

CFM 1295 1234 1182 1126 1075 1016 955 898 857

Heating

Rise (

Heating

Rise (

CFM 1345 1282 1235 1194 1140 1095 1027 974 921

Heating

Rise (

Heating

Rise (

CFM 1505 1452 1413 1358 1323 1282 1234 1169 1130

Heating

Rise (

Heating

Rise (

CFM 1545 1492 1449 1411 1362 1313 1278 1231 1188

Heating

Rise (

Heating

Rise (

CFM 1705 1643 1607 1568 1518 1483 1448 1404 1360

Heating

Rise (

Heating

Rise (

55 58 62 NA NA NA NA NA NA

o

F)

31 32 35 NA NA NA NA NA NA

o

C)

53 56 59 62 NA NA NA NA NA

o

F)

29 31 33 35 NA NA NA NA NA

o

C)

50 53 55 59 62 65 NA NA NA

o

F)

28 29 31 33 34 36 NA NA NA

o

C)

42 44 46 48 50 52 54 56 60

o

F)

24 24 25 26 28 29 30 31 33

o

C)

42 43 45 46 48 51 53 56 60

o

F)

23 24 25 26 27 28 30 31 33

o

C)

34 36 38 39 41 44 47 49 52

o

F)

19 20 21 22 23 24 26 27 29

o

C)

33 35 36 37 39 41 43 46 48

o

F)

18 19 20 21 22 23 24 25 27

o

C)

30 31 31 33 34 35 36 38 39

o

F)

16 17 17 18 19 19 20 21 22

o

C)

29 30 31 31 33 34 35 36 37

o

F)

16 17 17 17 18 19 19 20 21

o

C)

26 27 28 28 29 30 31 32 33

o

F)

14 15 15 16 16 17 17 18 18

o

C)

53 55 58 60 63 NA NA NA NA

o

F)

29 31 32 34 35 NA NA NA NA

o

C)

51 53 55 57 60 62 NA NA NA

o

F)

28 29 31 32 33 35 NA NA NA

o

C)

45 47 48 50 51 53 55 58 60

o

F)

25 26 27 28 29 29 31 32 33

o

C)

44 46 47 48 50 52 53 55 57

o

F)

24 25 26 27 28 29 30 31 32

o

C)

40 41 42 43 45 46 47 48 50

o

F)

22 23 24 24 25 25 26 27 28

o

C)

674D-- --A

21

Table 10 (cont) -- Dry Coil Air Delivery* -- Horizontal and Downflow Discharge -- Unit 674D----A24--60

UNIT

674D(N,P,E)WA48090

HEATING

RISE RANGE

35 --- 65oF

o

( 1 9 --- 3 6

674D-- --A

674D(N,P,E)WA48115

674D(N,P,E)WA48130

30 --- 60oF

( 1 7 --- 3 3

35 --- 65oF

( 1 9 --- 3 6

o

o

MOTOR

SPEED

Low

M e d ---

Low

Medium

C)

M e d ---

High

High Black

Low Blue

M e d ---

Low

Medium

C)

M e d ---

High

High Black

Low Blue

M e d ---

Low

Medium

C)

M e d ---

High

High Black

WIRE

COLOR

CFM 1402 1351 1311 1263 1224 1172 1136 1080 1041

1

Blue

Heating

Rise (

Heating

Rise (

CFM 1457 1404 1367 1318 1284 1233 1197 1144 1104

Heating

Pink

Rise (

Heating

Rise (

CFM 1736 1695 1642 1601 1553 1512 1465 1427 1381

2

Red

Heating

Rise (

Heating

Rise (

CFM 2149 2111 2062 2026 1980 1945 1905 1864 1793

Heating

Orange

Rise (

Heating

Rise (

CFM 2344 2306 2259 2203 2141 2070 1991 1902 1803

Heating

Rise (

Heating

Rise (

CFM 1402 1351 1311 1263 1224 1172 1136 1080 1041

Heating

Rise (

Heating

Rise (

CFM 1457 1404 1367 1318 1284 1233 1197 1144 1104

Heating

Pink

Rise (

Heating

Rise (

CFM 1736 1695 1642 1601 1553 1512 1465 1427 1381

2

Red

Heating

Rise (

Heating

Rise (

CFM 2149 2111 2062 2026 1980 1945 1905 1864 1793

Heating

Orange

1

Rise (

Heating

Rise (

CFM 2344 2306 2259 2203 2141 2070 1991 1902 1803

Heating

Rise (

Heating

Rise (

CFM 1402 1351 1311 1263 1224 1172 1136 1080 1041

Heating

Rise (

Heating

Rise (

CFM 1457 1404 1367 1318 1284 1233 1197 1144 1104

Heating

Pink

Rise (

Heating

Rise (

CFM 1736 1695 1642 1601 1553 1512 1465 1427 1381

2

Red

Heating

Rise (

Heating

Rise (

CFM 2149 2111 2062 2026 1980 1945 1905 1864 1793

Heating

Orange

1

Rise (

Heating

Rise (

CFM 2344 2306 2259 2203 2141 2070 1991 1902 1803

Heating

Rise (

Heating

Rise (

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

49 50 52 54 56 58 60 63 65

o

F)

27 28 29 30 31 32 33 35 36

o

C)

47 48 50 52 53 55 57 59 62

o

F)

26 27 28 29 29 31 32 33 34

o

C)

39 40 41 42 44 45 46 48 49

o

F)

22 22 23 24 24 25 26 26 27

o

C)

NA NA NA NA NA 35 36 36 38

o

F)

NA NA NA NA NA 19 20 20 21

o

C)

NA NA NA NA NA NA NA 36 38

o

F)

NA NA NA NA NA NA NA 20 21

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

60 NA NA NA NA NA NA NA NA

o

F)

33 NA NA NA NA NA NA NA NA

o

C)

50 51 53 54 56 57 59 NA NA

o

F)

28 28 29 30 31 32 33 NA NA

o

C)

40 41 42 43 44 45 46 47 48

o

F)

22 23 23 24 24 25 25 26 27

o

C)

37 38 38 39 41 42 44 46 48

o

F)

21 21 21 22 23 23 24 25 27

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

55 57 59 60 62 64 NA NA NA

o

F)

31 32 33 33 34 35 NA NA NA

o

C)

45 46 47 48 49 50 51 52 54

o

F)

25 25 26 26 27 28 28 29 30

o

C)

41 42 43 44 45 47 48 51 53

o

F)

23 23 24 24 25 26 27 28 30

o

C)

EXTERNAL STATIC PRESSURE (IN. W.C.)

22

Table 10 (cont) -- Dry Coil Air Delivery* -- Horizontal and Downflow Discharge -- Unit 674D----A24--60

UNIT

674D(N,P,E)WA60090

674D(N,P,E)WA60115

674D(N,P,E)WA60130

* Air delivery values a r e without air filter and a re for dry coil (See Table 8 --- 674D --- A Wet Coil Pressure Drop table).

1

Factory---shipped gas heating speed

2

Factory --- shipped heat pump speed

HEATING

RISE RANGE

35 --- 65oF

o

( 1 9 --- 3 6

30 --- 60oF

o

( 1 7 --- 3 3

35 --- 65oF

o

( 1 9 --- 3 6

MOTOR

SPEED

Low

M e d --- L o w Pink

Medium

C)

M e d --- H i g h Orange

High Black

Low Blue

M e d --- L o w Pink

Medium

C)

M e d ---

High

High Black

Low Blue

M e d --- L o w Pink

Medium

C)

M e d ---

High

High Black

WIRE

COLOR

CFM 1445 1389 1341 1281 1236 1189 1139 1072 1027

1

Blue

Heating

Rise (

Heating

Rise (

CFM 1678 1635 1602 1558 1513 1474 1438 1404 1349

Heating

Rise (

Heating

Rise (

CFM 1927 1893 1858 1824 1791 1759 1720 1689 1640

2

Red

Heating

Rise (

Heating

Rise (

CFM 2131 2088 2065 2013 1982 1941 1888 1860 1785

Heating

Rise (

Heating

Rise (

CFM 2461 2409 2339 2286 2192 2140 2062 1968 1874

Heating

Rise (

Heating

Rise (

CFM 1445 1389 1341 1281 1236 1189 1139 1072 1027

Heating

Rise (

Heating

Rise (

CFM 1678 1635 1602 1558 1513 1474 1438 1404 1349

Heating

Rise (

Heating

Rise (

CFM 1927 1893 1858 1824 1791 1759 1720 1689 1640

2

Red

Heating

Rise (

Heating

Rise (

CFM 2131 2088 2065 2013 1982 1941 1888 1860 1785

Heating

Orange

1

Rise (

Heating

Rise (

CFM 2461 2409 2339 2286 2192 2140 2062 1968 1874

Heating

Rise (

Heating

Rise (

CFM 1445 1389 1341 1281 1236 1189 1139 1072 1027

Heating

Rise (

Heating

Rise (

CFM 1678 1635 1602 1558 1513 1474 1438 1404 1349

Heating

Rise (

Heating

Rise (

CFM 1927 1893 1858 1824 1791 1759 1720 1689 1640

2

Red

Heating

Rise (

Heating

Rise (

CFM 2131 2088 2065 2013 1982 1941 1888 1860 1785

Heating

Orange

1

Rise (

Heating

Rise (

CFM 2461 2409 2339 2286 2192 2140 2062 1968 1874

Heating

Rise (

Heating

Rise (

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

47 49 51 53 55 57 60 63 NA

o

F)

26 27 28 29 31 32 33 35 NA

o

C)

41 42 42 44 45 46 47 48 50

o

F)

23 23 24 24 25 26 26 27 28

o

C)

35 36 37 37 38 39 40 40 41

o

F)

20 20 20 21 21 21 22 22 23

o

C)

NA NA NA NA NA 35 36 37 38

o

F)

NA NA NA NA NA 19 20 20 21

o

C)

NA NA NA NA NA NA NA 35 36

o

F)

NA NA NA NA NA NA NA 19 20

o

C)

60 NA NA NA NA NA NA NA NA

o

F)

33 NA NA NA NA NA NA NA NA

o

C)

52 53 54 56 57 59 60 NA NA

o

F)

29 30 30 31 32 33 34 NA NA

o

C)

45 46 47 48 49 49 51 51 53

o

F)

25 26 26 26 27 27 28 29 29

o

C)

41 42 42 43 44 45 46 47 49

o

F)

23 23 23 24 24 25 26 26 27

o

C)

35 36 37 38 40 41 42 44 46

o

F)

20 20 21 21 22 23 23 25 26

o

C)

NA NA NA NA NA NA NA NA NA

o

F)

NA NA NA NA NA NA NA NA NA

o

C)

57 59 60 62 64 65 NA NA NA

o

F)

32 33 33 34 35 36 NA NA NA

o

C)

50 51 52 53 54 55 56 57 59

o

F)

28 28 29 29 30 30 31 32 33

o

C)

45 46 47 48 49 50 51 52 54

o

F)

25 26 26 27 27 28 28 29 30

o

C)

39 40 41 42 44 45 47 49 51

o

F)

22 22 23 23 24 25 26 27 29

o

C)

NA --- Not allowed for heating speed
Note: Deduct field---supplied air filter pressure drop and wet coil pressure drop to obtain external static pressure available for ducting.
Shaded areas indicate speed/static combinations that are not permitted for dehumidification speed.

EXTERNAL STATIC PRESSURE (IN. W.C.)

674D-- --A

23

674D-- --A

Fig. 14 -- 208/230--1-- 60 Connection Wiring Diagram, Unit 674D

A10207C

24

674D-- --A

Fig. 14 Cont -- 208/230--1--60 Ladder Wiring Diagram, Unit 674D----A

A10207L

25

674D-- --A

Fig. 15 -- 208/230--3-- 60 Connection Wiring Diagram, Unit 674D-- -- A

A10208C

26

674D-- --A

Fig. 15 Cont. -- 208/230--3--60 Ladder Wiring Diagram, Unit 674D----A

A10208L

27

674D-- --A

A08019

Fig. 16 -- Cooling Charging Table--Subcooling

28

MAINTENANCE

To ensure continuing high performance and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment. This combination
heating/cooling unit should be inspected at least once each year by
a qualified service person. To troubleshoot cooling or heating of
units, refer to Tables 10, 11 and 12.

NOTE: Consult your local dealer about the availability of a
maintenance contract.

!

PERSONAL INJURY AND UNIT DAMAGE HAZARD

Failure to follow this warning could result in personal injury
or death and unit component damage.

The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills, tools
and equipment. If you do not possessthese, do not attemptto
perform any maintenance on this equipment,other than those
procedures recommended in the Owner’s Manual.

!

ELECTRICAL SHOCK AND EXPLOSION HAZARD

Failure to follow these warnings could result in personal
injury or death:

1. Turn off electrical power to the unit and install a lockout
tag before performing any maintenance or service on this
unit.

2. Use extreme caution when removing panels and parts.

3. Never place anything combustible either on or in contact
with the unit.

4. Should overheating occur or the gas supply fail to shut
off, turn off external main manual gas valve to the unit.
Then shut off electrical supply.

CUT HAZARD

Failure to follow this caution may result in personal injury.

When removing access panels (see Fig. 18) or performing
maintenance functions inside your unit, be aware of sharp
sheet metal parts and screws. Although special care is taken
to reduce sharp edges to a minimum, be extremely careful
when handling parts or reaching into the unit.

UNIT OPERATION HAZARD

Failure to follow this caution may result in improper
operation.

Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to
disconnecting when servicing.

The minimum maintenance requirements for this equipment are as
follows:

1. Inspect air filter(s) each month. Clean or replace when
necessary. Certain geographical locations may require more
frequent inspections.

2. Inspect indoor coil, outdoor coil, drain pan, and condensate
drain each cooling season for cleanliness. Clean when
necessary.

WARNING

WARNING

!

CAUTION

!

CAUTION

3. Inspect blower motor and wheel for cleanliness at the
beginning of each heating and cooling season. Clean when
necessary. For first heating and cooling season, inspect
blower wheel bi--monthly to determine proper cleaning
frequency.

4. Check electrical connections for tightness and controls for
proper operation each heating and cooling season. Service
when necessary. Ensure electrical wiring is not in contact
with refrigerant tubing or sharp metal edges.

5. Check and inspect heating section before each heating
season. Clean and adjust when necessary.

6. Check flue hood and remove any obstructions, if necessary.

Air Filter

IMPORTANT: Never operate the unit without a suitable air filter

in the return--air duct system. Always replace the filter with the
same dimensional size and type as originally installed. (See Table 1
for recommended filter sizes.)

Inspect air filter(s) at least once each month and replace
(throwaway--type) or clean (cleanable--type) at least twice during
each heating and cooling season or whenever the filter(s) becomes
clogged with dust and/or lint.

Indoor Blower and Motor

NOTE: All motors are prelubricated. Do not attempt to lubricate

these motors.

For longer life, operating economy, and continuing efficiency,
clean accumulated dirt and grease from the blower wheel and
motor annually.

!

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury
or death.

Disconnect and install lockout tag on electrical power to the
unit before cleaning and lubricating the blower motor and
wheel.

Cleaning the Blower Motor and Wheel

1. Remove and disassemble blower assembly as follows:

a. Remove blower access panel (see Fig. 18).

b. Disconnect 5 pin plug and 4 pin plug from indoor

blower motor. Remove capacitor if required.

c. On all units, remove blower assembly from unit.

Remove screws securing blower to blower partition and
slide assembly out. Be careful not to tear insulation in
blower compartment.

d. Ensure proper reassembly by marking blower wheel and

motor in relation to blower housing before disassembly.

e. Loosen setscrew(s) that secures wheel to motor shaft.

Remove screws that secure motor mount brackets to
housing, and slide motor and motor mount out of
housing.

2. Remove and clean blower wheel as follows:

a. Ensure proper reassembly by marking wheel orientation.

b. Lift wheel from housing. When handling and/or

cleaning blower wheel, be sure not to disturb balance
weights (clips) on blower wheel vanes.

c. Remove caked--on dirt from wheel and housing with a

brush. Remove lint and/or dirt accumulations from
wheel and housing with vacuum cleaner, using soft
brush attachment. Remove grease and oil with mild
solvent.

d. Reassemble wheel into housing.

e. Reassemble motor into housing. Be sure setscrews are

tightened on motor shaft flats and not on round part of
shaft. Reinstall blower into unit. Reinstall capacitor.

29

674D-- --A

f. Connect 5 pin plug and 4 pin plug to indoor blower

motor.

g. Reinstall blower access panel (see Fig. 18).

3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.

Integrated
Gas Unit
Controller
(IGC)

Auto Transformer
fuses used on 460
volt units only.
(Hidden)

Interface Fan
Board (IFB)

Induced Draft
Motor

1. Remove the induced draft blower assembly according to
directions in the Induced Draft Blower Assembly section.

2. Remove the 11 screws holding the flue collector box cover
(See Fig. 17) to the heat exchanger assembly. Inspect the
heat exchangers.

3. Clean all surfaces, as required, using a wire brush.

Limit Switch

Remove blower access panel (see Fig. 18). Limit switch is located
on the fan partition.

Burner Ignition

Unit is equipped with a direct spark ignition 100 percent lockout
system. Ignition module (IGC) is located in the control box (See
Fig. 17). Module contains a self--diagnostic LED. During
servicing, refer to label diagram or Table 5 in these instructions for
LED interpretation.

If lockout occurs, unit may be reset by either momentarily

Fan Partition
Mounting
Bracket

Flue
Collector
Box

Inducer
Blower
Housing

Burner
Rack

Mounting
Screw

Rollout
Switch

Fig. 17 -- Blower Housing and Flue Collector Box

A09193

interrupting power supply to unit or by turning selector switch to
OFF position at the thermostat.

Main Burners

At the beginning of each heating season, inspect for deterioration
or blockage due to corrosion or other causes. Observe the main
burner flames and adjust, if necessary.

674D-- --A

Removal of Gas T

rain

To remove the gas train for servicing:

1. Shut off main gas valve.

2. Shut off power to unit and install lockout tag.

3. Remove control access panel (See Fig. 18).

4. Disconnect gas piping at unit gas valve.

5. Remove fan partition mounting bracket (2 screws located
on the left side of the control compartment on the fan parti­tion panel). Slide bracket forward, bottom first, to remove
(See Fig. 17).

6. Remove wires connected to gas valve. Mark each wire.

7. Remove the mounting screw that attaches the burner rack to

CONTROL
ACCESS
PAN EL

A09207

COMPRESSOR
ACCESS PANEL

BLOWER
ACCESS
PAN EL

Fig. 18 -- Unit Access Panels

Induced Draft (combustion air) Blower Assembly

The induced--draft blower assembly consists of the inducer motor,
the blower housing, and the induced--draft blower wheel.

Clean periodically to assure proper airflow and heating efficiency.
Inspect blower wheel every fall and periodically during the heating
season. For the first heating season, inspect blower wheel
bimonthly to determine proper cleaning frequency.

To inspect blower wheel, remove draft hood assembly. Shine a
flashlight into opening to inspect wheel. If cleaning is required,
remove induced--draft blower assembly as follows:

1. Remove control access panel (See Fig. 18).

2. Remove the 5 screws that attach induced--draft blower as­sembly to the flue collector box cover.

3. Slide the assembly out of the unit. (See 20). Clean the
blower wheel. If additional cleaning is required, continue
with Steps 4 and 5.

4. To remove blower wheel, remove 2 setscrews.

5. To remove inducer motor, remove screws that hold the
inducer motor to the blower housing.

6. To reinstall, reverse the procedure outlined above.

Flue Gas Passageways

To inspect the flue collector box and upper areas of the heat

the unit base (See Fig. 17).

8. Partially slide the burner rack out of the unit (see Fig. 17
and 20). Remove ignitor and sensor wires at the burner as­sembly. Remove rollout switch wires.

9. Slide the burner rack out of the unit (See Fig. 17 and 20).

10. T o reinstall, reverse the procedure outlined above.

Outdoor Coil, Indoor Coil, and Condensate Drain Pan

Inspect the outdoor coil, indoor coil, and condensate drain pan at
least once each year. The coils are easily cleaned when dry;
therefore, inspect and clean the coils either before or after each
cooling season. Remove all obstructions, including weeds and
shrubs, that interfere with the airflow through the condenser coil.

Straighten bent fins with a fin comb. If coated with dirt or lint,
clean the coils with a vacuum cleaner, using the soft brush
attachment. Be careful not to bend the fins. If coated with oil or
grease, clean the coils with a mild detergent--and--water solution.
Rinse coils with clear water, using a garden hose. Be careful not to
splash water on motors, insulation, wiring, or air filter(s). For best
results, spray outdoor coil fins from inside to outside the unit. On
units with an outer and inner condenser coil, be sure to clean
between the coils. Be sure to flush all dirt and debris from the unit
base.

Inspect the drain pan and condensate drain line when inspecting
the coils. Clean the drain pan and condensate drain by removing all
foreign matter from the pan. Flush the pan and drain tube with
clear water. Do not splash water on the insulation, motor, wiring, or
air filter(s). If the drain tube is restricted, clear it with a “plumbers
snake” or similar probe device. Ensure that the auxiliary drain port
above the drain tube is also clear.

exchanger:

30

BLOWER
HOUSING

2 SETSCREWS
(HIDDEN)

Fig. 19 -- Removal of Motor and Blower Wheel

Fig. 20 -- Burner Rack Removed

FEEDER TUBE

STUB TUBE

DEFROST
THERMOSTAT

Fig. 21 -- Defrost Thermostat Location

C99085

A07680

C99029

A07680

Fig. 22 -- Burner Rack Removed

Outdoor Fan

!

UNIT OPERATION HAZARD

Failure to follow this caution may result in damage to unit
components.

Keep the outdoor fan free from all obstructions to ensure
proper cooling operation. Never place articles on top of the
unit.

1. Remove 6 screws holding outdoor grille and motor to top
cover.

2. Turn motor/grille assembly upside down on top cover to
expose the fan blade.

3. Inspect the fan blades for cracks or bends.

4. If fan needs to be removed, loosen the setscrew and slide the
fan off the motor shaft.

5. When replacing fan blade, position blade back to the same
position as before.

6. Ensure that setscrew engages the flat area on the motor shaft
when tightening.

7. Replace grille.

CAUTION

Electrical Controls and Wiring

Inspect and check the electrical controls and wiring annually. Be
sure to turn off the gas supply, and then the electrical power to the
unit.

Remove access panels (see Fig. 18) to locate all the electrical
controls and wiring. Check all electrical connections for tightness.
Tighten all screw connections. If any discolored or burned
connections are noticed, disassemble the connection, clean all the
parts, re--strip the wire end and reassemble the connection properly
and securely.

After inspecting the electrical controls and wiring, replace the
access panels (see Fig. 18). Start the unit, and observe at least one
complete heating cycle and one complete cooling cycle to ensure
proper operation. If discrepancies are observed in any operating
cycle, or if a suspected malfunction has occurred, check each
electrical component with the proper electrical instrumentation.
Refer to the unit wiring label when making these checkouts.

NOTE: Refer to the heating and/or cooling sequence of operation
in this publication as an aid in determining proper control
operation.

Refrigerant Circuit

Annually inspect all refrigerant tubing connections and the unit
base for oil accumulations. Detecting oil generally indicates a
refrigerant leak.

674D-- --A

31

T2 C C O

OF1

OF2

DFT

O R W

T1 Y

2

Y C

P1

SPEEDUP

30

60

J1

674D-- --A

P3

DFT

INTERVAL TIMER

90

OFF

30

SHIFT

120

60

ON

QUIET

Speedup
Pins

!

EXPLOSION, PERSONAL INJURY AND
ENVIRONMENTAL HAZARD

Failure to follow this warning could result in personal injury,
death or property damage.

System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal. Use all
service ports and open all flow--control devices, including
solenoid valves.

If oil is detected or if low cooling performance is suspected,
leak-- test all refrigerant tubing using an electronic leak--detector,
halide torch, or liquid--soap solution. If a refrigerant leak is
detected, refer to the Check for Refrigerant Leaks section.

If no refrigerant leaks are found and low cooling performance is
suspected, refer to the Checking and Adjusting Refrigerant Charge
section.

WARNING

Quiet
Shift

Fig. 23 -- Defrost Control

Gas Input

The gas input does not require checking unless improper heating
performance is suspected. If a problem exists, refer to the Start--Up
section.

Indoor Airflow

The heating and/or cooling airflow does not require checking
unless improper performance is suspected. If a problem exists, be
sure that all supply-- and return--air grilles are open and free from
obstructions, and that the air filter is clean. When necessary, refer to

Defrost interval
DIP switches

the Indoor Airflow and Airflow Adjustments section to check the
system airflow.

Check Defrost Thermostat

The defrost thermostat is usually located on the lowest liquid
leaving circuit of the left condenser coil (see Fig. 21). The
thermostat closes at 32_F(0_C) and opens at 65_F(18_C).

Puron Items
Metering Device

Piston)

This unit uses both a hard shutoff, balance port TXV in the indoor
coil and a piston in each side of the outdoor coil. The TXV
maintains a constant superheat at the evaporator coil exit (cooling
mode) resulting in higher overall system efficiency.

Pressure Switches

Pressure switches are protective devices wired into control circuit
(low voltage). They shut off compressor if abnormally high or low
pressures are present in the refrigeration circuit. These pressure
switches are specifically designed to operate with Puron (R--410A)
systems. R--22 pressure switches must not be used as replacements
for the Puron (R--410A) system.

Loss of Charge Switch

This switch is located on the liquid line and protects against low
suction pressures caused by such events as loss of charge, low
airflow across indoor coil, dirty filters, etc. It opens on a pressure
drop at about 20 psig. If system pressure is above this, switch
should be closed. To check switch:

1. Turn off all power to unit.

(Thermostatic Expansion Valve &

A08020

32

Fig. 24 -- Refrigerant Circuit

674D-- --A

C99097

2. Disconnect leads on switch.

3. Apply ohm meter leads across switch. You should have
continuity on a good switch.

NOTE: Because these switches are attached to refrigeration
system under pressure, it is not advisable to remove this device for
troubleshooting unless you are reasonably certain that a problem
exists. If switch must be removed, remove and recover all system
charge so that pressure gauges read 0 psi. Never open system
without breaking vacuum with dry nitrogen.

High--Pressure Switch

The high--pressure switch is located in the discharge line and
protects against excessive condenser coil pressure. It opens at 650
psig.

High pressure may be caused by a dirty outdoor coil, failed fan
motor, or outdoor air recirculation. To check switch:

1. Turn off all power to unit.

2. Disconnect leads on switch.

3. Apply ohm meter leads across switch. You should have
continuity on a good switch.

Copeland Scroll Compressor (Puron Refrigerant)

The compressor used in this product is specifically designed to
operate with Puron (R--410A) refrigerant and cannot be
interchanged.

The compressor is an electrical (as well as mechanical) device.
Exercise extreme caution when working near compressors. Power
should be shut off, if possible, for most troubleshooting techniques.
Refrigerants present additional safety hazards.

!

WARNING

EXPLOSION HAZARD

Failure to follow this warning could result in personal injury
or death and/or property damage.

Wear safety glasses and gloves when handling refrigerants.
Keep torches and other ignition sources away from
refrigerants and oils.

The scroll compressor pumps refrigerant throughout the system by
the interaction of a stationary and an orbiting scroll. The scroll
compressor has no dynamic suction or discharge valves, and it is
more tolerant of stresses caused by debris, liquid slugging, and
flooded starts. The compressor is equipped with an internal
pressure relief port. The pressure relief port is a safety device,
designed to protect against extreme high pressure. The relief port
has an operating range between 550 and 625 psig differential
pressure.

33

HP S

ACCUMULATOR

COMPRESSOR

LEGEND

HPS – High Pressure Switch
LCS – Loss of Charge Switch

Accurater

®

Metering De vice

Arrow indicates direction of flo w

OUTDOOR COIL

Bypass

Position

TXV in Metering

Position

LCS

INDOOR COIL

674D-- --A





C03011

Fig. 25 -- Typical Heat Pump Operation, Cooling Mode

INDOOR COIL

ACCUMULATOR

HP S

COMPRESSOR

OUTDOOR COIL

Metering

Position

TXV in Bypass

Position

LCS

LEGEND

HPS – High Pressure Switch
LCS – Loss of Charge Switch

®

Accurater

Metering De vice

Arrow indicates direction of flo w

C03012

Fig. 26 -- Typical Heat Pump Operation, Heating Mode

!

WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could result in personal injury
or equipment damage.

This system uses Puron (R --410A) refrigerant which has
higher operating pressures than R--22 and other refrigerants.
No other refrigerant may be used in this system. Gauge set,
hoses,and recovery systemmustbe designedto handle Puron.
If you are unsure, consult the equipment manufacturer.

Refrigerant System

This information covers the refrigerant system of the 674D ----A,
including the compressor oil needed, servicing systems on roofs
containing synthetic materials, the filter drier and refrigerant
charging.

Compressor Oil

If additional oil is needed use Uniqema RL32--3MAF. If this oil is
not available, use Copeland Ultra 32CC or Mobil Artic EAL22CC.
This oil is extremely hygroscopic, meaning it absorbs water
readily. POE oils can absorb 15 times as much water as other oils
designed for HCFC and CFC refrigerants. Take all necessary
precautions to avoid exposure of the oil to the atmosphere.

34

Servicing Systems on Roofs and with Synthetic materials

POE (polyolester) compressor lubricants are known to cause long
term damage to some synthetic roofing materials.

Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one year or more.
When performing any service that may risk exposure of
compressor oil to the roof, take appropriate precautions to protect
roofing. Procedures which risk oil leakage include, but are not
limited to, compressor replacement, repairing refrigerant leaks,
replacing refrigerant components such as filter drier, pressure
switch, metering device, coil, accumulator, or reversing valve.

Synthetic Roof Precautionary Procedure

1. Cover extended roof working area with an impermeable
polyethylene (plastic) drip cloth or tarp. Cover an
approximate 10x10 ft (3x3 m) area.

2. Cover area in front of the unit service panel with a terry
cloth shop towel to absorb lubricant spills and prevent
run--offs, and protect drop cloth from tears caused by tools
or components.

3. Place terry cloth shop towel inside unit immediately under
component(s) to be serviced and prevent lubricant run--offs
through the louvered openings in the unit base.

4. Perform required service.

5. Remove and dispose of any oil contaminated material per
local codes.

Liquid Line Filter Drier

This filter drier is specifically designed to operate with Puron. Use
only factory--authorized components. Filter drier must be replaced
whenever the refrigerant system is opened. When removing a filter
drier, use a tubing cutter to cut the drier from the system. Do not
unsweat a filter drier from the system. Heat from unsweating will
release moisture and contaminants from drier into system.

Puron (R--410A) Refrigerant Charging

Refer to unit information plate and charging chart. Some R--410A
refrigerant cylinders contain a dip tube to allow liquid refrigerant to
flow from cylinder in upright position. For cylinders equipped
with a dip tube, charge Puron units with cylinder in upright
position and a commercial metering device in manifold hose.
Charge refrigerant into suction--line.

TROUBLESHOOTING

Use the Troubleshooting Guides (See Tables 10--12) if problems
occur with these units.

START--UP CHECKLIST

Use Start-- Up checklist to ensure proper start--up procedures are
followed.

674D-- --A

PURONR (R--410A) QUICK REFERENCE GUIDE

S Puron refrigerant operates at 50--70 percent higher pressures than R--22. Be sure that servicing equipment and replacement

components are designed to operate with Puron

S Puron refrigerant cylinders are rose colored.
S Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
S Puron systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when

charging into suction line with compressor operating

S Manifold sets should be minimum 700 psig high side and 180 psig low side with 550 psig low--side retard.
S Use hoses with minimum 700 psig service pressure rating.
S Leak detectors should be designed to detect HFC refrigerant.
S Puron, as with other HFCs, is only compatible with POE oils.
S Vacuum pumps will not remove moisture from oil.
S Do not use liquid--line filter driers with rated working pressures less than 600 psig.
S Do not leave Puron suction line filter driers in line longer than 72 hrs.
S Do not install a suction-- line filter drier in liquid line.
S POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
S POE oils may cause damage to certain plastics and roofing materials.
S Wrap all filter driers and service valves with wet cloth when brazing.

S A factory approved liquid--line filter drier is required on every unit.
S Do NOT use an R--22 TXV.
S Never open system to atmosphere while it is under a vacuum.
S When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter

driers. Evacuate to 500 microns prior to recharging.

S Do not vent Puron into the atmosphere.
S Observe all warnings, cautions,andbold text.
S All indoor coils must be installed with a hard shutoff Puron TXV metering device.

35

Table 11 – Troubleshooting Guide -- Cooling or Heat Pump Heating Mode

SYMPTOM CAUSE REMEDY

Compressor and Outdoor fan will not
start.

Compressor will not start but Outdoor
fan runs.

Three--- phase scroll compressor makes
excessive noise, and there may
be a low pressure differential.

Compressor cycles (other than normally
satisfying thermostat).

674D-- --A

Compressor operates continuously.

Excessive head pressure.

Head pressure too low.

Excessive suction pressure.

Suction pressure too low.

Compressor runs but outdoor fan does
not

Powe r Failure Call power company.
Fuse blown or circuit breaker tripped Replacefuseorresetcircuitbreaker.
Defective thermostat, contactor, transformer, or control
relay
Insufficient line voltage Determine cause and correct.
Incorrect or faulty wiring Check wirin g diagram and rewire correctly.
Thermostat setting too high Lower thermostat setting below room temperature.
Faulty wiring or loose connections in compressor circuit Check wiring and repair or replace.
Compressor motor burned out, seized, or internal over­load open
Defective run/start capacitor, overload, start relay Determine cause and replace.

Onelegof3---phasepowerdead

Scroll compressor is rotating in the wrong direction

Refrigerant overcharge or undercharge

Defective compressor Replace and determine cause.
Insufficient line voltage Determine cause and correct.
Blocked Outdoor Determine cause and correct.
Defective run/start capacitor, overload or start relay Determine cause and replace.
Defective thermostat Replace thermostat.
Faulty Outdoor--- fan motor or capacitor Replace.
Damaged reversing valve Determine cause and correct
Restriction in refrigerant system Locate restriction and remove.
Dirty air filter Replace filter.
Unit undersized for load Decrease load or increase un it size.
Thermostat set too low Reset thermostat.
Low refrigerant charge Locate leak, repair, and recharge.
Mechanical damage in compressor. Replace compressor.
Air in system Recover refrigerant, evacuate system, and recharge.

Frosted coil with incorrect defrost operation

Outdoor coil dirty or restricted Clean coil or r emove restriction .
Dirty air filter Replace filter.
Dirty Indoor or Outdoor coil Clean coil.
Refrigerant overcharged Recover excess refrigerant.
Air in system Recover refrigerant, evacuate system, and recharge.
Indoor or Outdoor air restricted or air short --- cycling Determine cause and correct.
Low refrigerant charge Check for leaks, repair, and recharge.
Compressor IPR leaking Replace compressor.
Restrictioninliquidtube Remove restriction.
High heat load Check for source and eliminate.
Compressor IPR l eaking Replace compressor.
Refrigerant overcharged Recover excess refrigerant.
Reversing valve hung up or leaking internally Replace valve
Dirty air filter Replace Filter.
Low refrigerant charge Check for leaks, repair, and recharge.
Metering device or low side restricted Remove source of restriction.

Insufficient Indoor airflow

Temperature too low in conditioned ar ea Reset thermostat.
Outdoor ambient below 55°F (12.8°C) Install low --- ambient kit.
Field ---installed filter ---drier restr icted Replace.

(Heat) Outdoor coil frosted

NC (normally closed) contacts on defrost board open

Replace component.

Determine cause Replace compressor.

Replace fuse or reset circuit breaker. D etermine
cause.

Correct the direction of rotation by reversing the
3--- phase power leads to the unit.

Recover refrigerant, evacuate system, and recharge
to capacities shown on nameplate.

Check defrost time settings, Reset as necessary
Check defrost temperature switch, Replace as nec­essary

Increase air quantity. Check filter — replace if neces­sary.

Move timer on control board to 30 minutes between
defrost cycles
Check condition of relay on board Replace if neces­sary

36

Table 12 – Troubleshooting Guide–Heating

SYMPTOM CAUSE REMEDY

Burners will not ignite

Inadequate heating

Poor flame characteristics

Water in gas line Drain. Install drip leg.
No power to furnace Check power supply fuses, wiring or circuit breaker.

No 24--v power supply to control circuit

Mis--wired or loose connections Check all wiring and wire nut connections

Misaligned spark electrodes

No gas at main burners

Dirty air filter Clean or replace filter as necessary
Gas input to furnace too low Check gas pressure at manifold match with that on unit nameplate
Unit undersized for application Replace with proper unit or add additional unit
Restricted airflow Clean or replace filter. Remove any restriction.

Limit switch cycles main burners

Incomplete combustion results in: Aldehyde odors,
carbon monoxide, sooting flame, floating flame

Check transformer.
NOTE: Some transformers have internal over-- current protection
that requires a cool--down period to reset.

Check flame ignition and sense electrode positioning.
Adjust as necessary.

1. Check gas line for air. Purge as necessary. NOTE: After purging
gas line of air, wait at least 5 minutes for any gas to dissipate be­fore attempting to light unit.

2. Check gas valve.

Check rotation of blower, temperature rise of unit. Adjust as neces­sary.

1. Tighten all screws around burner compartment

2. Cracked heat exchanger. Replace.

3. Unit over --fired. Reduce input (change orifices or adjust gas line
or manifold pressure).

4. Check burner alignment.

5. Inspect heat exchanger for blockage. Clean as necessary.

Table 13 – Troubleshooting Guide–LED Error Codes

SYMPTOM CAUSE REMEDY

No Power or Hardware fail­ure
(LED OFF)

Limit switch faults
(LED 2 flashes)

Flame sense fault
(LED 3 flashes)

4 consecutive limit switch
faults
(LED 4 flashes)

Ignition lockout
(LED 5 flashes)

Pressure Switch Fault
(LED 6 flashes)

Rollout switch fault
(LED 7 flashes)

Internal control fault
(LED 8 flashes)

Temporary 1 hr auto reset
(LED 9 flashes)

*WARNING : If the IGC must be replaced, be sure to ground yourself to dissipate any electrical charge that my be present before handling new control
board. The IGC is sensitive to static electricity and my be damaged if the necessary precautions are not taken.

IMPORTANT: Refer to Table 11 - -- Troubleshooting Guide --- Heating for additional troubleshooting analysis.
LEGEND

IGC—Integrated Gas Unit Controller
LED—Light--- Emitting Diode

Loss of power to control module (IGC)*.

High temperature limit switch is open.

The IGC* sensed flame that should not be present. Reset unit. If problem persists, replace control board.

Inadequate airflow to unit.

Unit unsuccessfully attempted ignition for 15 minutes.

Open pressure switch.

Rollout switch has opened.

Microprocessor has sensed an error in the software
or hardware.

Electrical interference impeding IGC software

Check 5-- amp fuse son IGC*, power to unit, 24-- v circuit breaker,
and transformer. Units without a 24--v circuit breaker have an
internal overload in the 24--v transformer. If the overload trips,
allow 10 minutes for automatic reset.

Check the operation of the indoor (evaporator) fan motor. Ensure
that the supply--air temperature rise is in accordance with the
range on the unit nameplate. Clean or replace filters.

Check the operation of the indoor (evaporator) fan motor and that
supply--air temperature rise agrees with range on unit nameplate
information.

Check ignitor and flame sensor electrode spacing, gaps, etc.
Ensure that fame sense and ignition wires are properly terminated.
Verify that unit is obtaining proper amount of gas.

Verify wiring connections to pressure switch and inducer motor.
Verify pressure switch hose is tightly connected to both inducer
housing and pressure switch. Verify inducer wheel is properly
attached to inducer motor shaft. Verify inducer motor shaft is turn­ing.

Rollout switch will automatically reset, but IGC* will continue to
lockout unit. Check gas valve operation. Ensure that induced--draft
blower wheel is properly secured to motor shaft. Inspect heat
exchanger. Reset unit at unit disconnect.

If error code is not cleared by resetting unit power, replace the
IGC*.

Reset 24--v. to control board or turn thermostat off, then on again.
Fault will automatically reset itself in one (1) hour.

674D-- --A

37

START--UP CHECKLIST

(Remove and Store in Job Files)

I. PRELIMINARY INFORMATION

MODEL NO.:

SERIAL NO.:
DATE:

TECHNICIAN:

II. PRESTART-- UP (Insert check mark in box as each item is completed)

( ) VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT

( ) REMOVE ALL SHIPPING HOLD DOWN BOLTS AND BRACKETS PER INSTALLATION INSTRUCTIONS
( ) CHECK ALL ELECTRICAL CONNECTIONS AND TERMINALS F OR TIGHTNESS
( ) CHECK GAS PIPING FOR LEAKS (WHERE APPLICABLE)

( ) CHECK THAT INDOOR (EVAPORATOR) AIR FILTER IS CLEAN AND IN PLACE
( ) VERIFY THAT UNIT INSTALLATION IS LEVEL

( ) CHECK FAN WHEEL, AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND SETSCREW TIGHTNESS

III. START--UP

ELECTRICAL

674D-- --A

SUPPLY VOLTAGE

COMPRESSOR AMPS
INDOOR (EVAPORATOR) FAN AMPS

TEMPERATURES

OUTDOOR (CONDENSER) AIR TEMPERATURE DB
RETURN--AIR TEMPERATURE DB WB

COOLING SUPPLY AIR DB WB
HEAT PUMP SUPPLY AIR__________________

GAS HEAT SUPPLY AIR

PRESSURES

GAS INLET PRESSURE IN. W.C.

GAS MANIFOLD PRESSURE IN. W.C.
REFRIGERANT SUCTION PSIG, SUCTION LINE TEMP*
REFRIGERANT DISCHARGE PSIG, LIQUID TEMP{
( ) VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS
GAS HEAT TEMPERATURE RISE

TEMPERATURE RISE (See Literature) RANGE
MEASURED TEMPERATURE RISE

* Measured at suction inlet to compressor
{ Measured at liquid line leaving condenser.

38

VERTICAL ECONOMIZER

(FACTORY INSTALLED OPTION)

GENERAL

Economizers are recommended for only commercial packaged
products that have X13 motors. The Economizer system utilizes
the latest technology available for integrating the use of free
cooling with mechanical cooling for rooftop units. The solid state
control system optimizes energy consumption, zone comfort, and
equipment cycling by operating the compressors when the outdoor
air temperature is too warm, integrating the compressor with
outdoor air when free cooling is available, and locking out the
compressor when outdoor air temperature is too cold. Demand
ventilation is supported.

The Economizer system utilizes gear--drive technology with a
direct--mount spring return actuator that will close upon loss of
power. The Economizer system comes standard with an outdoor air
temperature sensor, a supply air temperature sensor, and low
temperature compressor lockout switch. Indoor enthalpy, outdoor
enthalpy, and CO

Barometric relief dampers provide natural building pressurization
control. Barometric relief dampers are built into the design and are
standard. See Table 14 for Hood Package contents. See Table 15
forsensorusage.

SMALL CHASSIS

(sizes 30 and 36)

Qty Content Description Qty Content Description

1 Hood Side, Right 1 Hood Side, Right

1 Hood Side, Left 1 Hood Side, Left

2 Angle, Filter 2 Angle, Filter

1

(20--- 1/2” x 16--- 1/2 x 1”)

(521 x 419 x 25 mm)

18

(#10 --- 14 x 5/8” w/Seal

2

( # 8 --- 1 8 x 3 / 4 ” T y pe B P a n

APPLICATION

Outdoor A ir Dry Bulb

Single Enthalpy HH57AC078

Differential Enthalpy HH57AC078 and CRENTDIF004A00*

CO2for DCV Control

U s i n g a W a l l --- M o u n t e d

CO

Sensor

2

CO2for DCV Control

U s i n g a D u c t ---

Mounted CO

*CRENTDIF004A00 accessory is used on many different base units. As
such, these kits may contain parts that will not be needed for installation.

{33ZCSENCO2 and CGCDXSEN004A00 are accessory CO
**33ZCASPC02 AND CGCDXASP00100 are accessory aspirator boxes

required for duct --- mounted applications.
{{CRCBDIOX005A00 is a n accessory that contains both 33ZCSENCO2

AND 33ZVASPC02 accessories.

sensors are available for field installation.

2

Table 14 – Package Contents

LARGE CHASSIS

(sizes 42, 48, and 60)

Aluminum Filter

1

Screws

18

Washer)

Screws

2

Head)

1 Bracket, Sensor

Aluminum Filter

(20--- 1/2” x 16--- 1/2 x 1”)

(521 x 419 x 25 mm)

(#10 --- 14 x 5/8” w/Seal

( # 8 --- 1 8 x 3 / 4 ” T y pe B P a n

Table 15 – Economizer Sensor Usage

Sensor

2

ECONOMIZER WITH OUTDOOR AIR DRY BULB

None, The outdoor air dry bulb sensor is factory

33ZCSENC02 or CGCDXSEN004A00

33ZCSENC02 or

CGCDXSEN004A00{
and 33ZCASPCO2 or
CGCDXASP00100**

SENSOR

Accessories Required

installed.

or CRCBDIOX005A00{{

Screws

Washer)

Screws

Head)

sensors.

2

ACCESSORIES

The economizer has several field--installed accessories available to
optimize performance. Refer to Table 16 for authorized parts.

Table 16 – Accessory List

DESCRIPTION PA RT N UM BE R

Outdoor Air Enthalpy Sensor HH57AC078

Indoor Air Enthalpy Sensor CRENTDIF004A00

Return Air CO2Sensor (4--- 20 mA) CRCBDIOX005A00

CO2Room Sensor (4 ---20 mA)

Aspirator Box for duct Mount CO2Sensor

( 4 --- 2 0 m A )

Space Temperature and CO2Room

Sensor with Override (4 ---20mA)

Space Temperature and CO2Room

Sensor with Override and Set Point

( 4 --- 2 0 m A )

Heat Pump Relay Package CPRLYKIT001A00

33ZCSENX02 Or

CGCDXSEN004A00

33ZCASPC02 Or

CGCDXASP001A00

33ZCT55C02

33ZCT56C02

INSTALLATION

Small Chassis

To install the Vertical Economizer on the small chassis perform the
following procedure:

1. Turn off unit power supply and install lockout tag.

!

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury or death.

Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be more
than one disconnect switch. Turn off accessory heater
power switch if applicable.

2. Remove economizer hood top panel from the return side of
the unit. See Fig. 27. Keep screws and panel next to the
unit.

3. Open economizer hood package found on the top skid.

4. Remove red shipping tape that attaches the outside air
temperature (OAT) sensor to the economizer assembly.
Using two #8 fasteners, found in the hood package, attach
the OAT sensor to the economizer according to Fig. 28.

NOTE: See label attached to economizer for OAT installing
details.

5. Remove horizontal return duct cover panel and cut the wire
ties that hold the hood divider to the economizer assembly.
Slide hood divider off from the two slots holding it in place
and place next to the unit. See Fig. 29.

NOTE: Gas units have a flue hood attached to the hood divider.
Unscrew the fastener holding the flue hood in place and dispose
the screw. Follow unit’s literature for flue hood installations.

674D-- --A

39

6. Replace horizontal return duct cover panel. Screw in place
ensuring all seams are air and watertight.

7. Install the 2 angle filter brackets to the right and left hood
side panels respectively with the #10 screws provided. See
Fig. 30.

8. Assemble hood according to Fig. 31 screwing together with
provided #10 sheet metal screws.

9. Install assembled hood over the economizer opening in the
replacement return chamber panel. See Fig. 32. Screw in
place through pre-punched holes. Make sure all seams are
air watertight.

NOTE: The two wires that connect to the outside air temperature
sensor (OAT) should remain accessible.

10. Connect the outside air temperature sensor (OAT) to the
economizer per wiring diagram.

11. Open the filter clips on the inside of the hood top. Insert the
aluminum filter into the hood and close the clips to hold in
place. See Fig. 33.

12. Toreplace12x20x1(304.8mm x 508mm x 25.4mm) air
filters, open the filter access door (horizontal return duct
cover panel), remove old filters and install new disposable
filters in filter rack. See Table 17 for filter part number.

674D-- --A

OAT Sensor

Fig. 27 -- Economizer Hood Top Panel Removal

Hood Top
Panel

A09689

Table 17 – Filter Part Number

DESCRIPTION PART NUMBER

Indoor Coil Air Filter

12 x 20 x 1

(304.8 x 508 x 25.4 mm)

KH01AA312

OAT Sensor

Fig. 28 -- Oat Sensor Installed

A09690

NOTE: The economizer control settings and the filters are
accessible through the filter access door.

13. Economizer controls are set to a standard factory setting.
Nevertheless, you can adjust these settings through the filter
access door. Review the settings in the Operation section:

(1.) The standard economizer controller has a factory

setting of “C” for the outdoor air temperature
changeover and 63_F(17_C) for the supply air
(mixed air) temperature sensor. The outdoor air
temperature changeover setting is adjusted on the
sensor by setting the dip switches on the sensor.
The ABCD potentiometer on the economizer
controller should be set to the “D” position.

(2.) The low ambient compressor lockout switch setting

is fixed at 42_F(5.6_C).

(3.) The minimum position for the outdoor air damper

can be configured at the controller. When not using

2

sensor, the DCV Max potentiometer must be

aCO
completely closed (CCW) for the Minimum Posi­tion potentiometer to function correctly.

(4.) Settings for the optional outdoor enthalpy sensor,

indoor enthalpy sensor, and CO

sensor can also be

2

configured at the controller.

14. Replace the filter access panel. Screw in place ensuring all
seams are air and watertight.

15. Install all economizer accessories then power HVAC unit
and test cycle economizer.

40

Horizontal
Return
Duct Cover
Panel

Hood
Divider
(Removed)

Hood
Divider

674D-- --A

A09691

Fig. 29 -- Horizontal Return Duct Cover Panel Removal

Left Hood
Side Panel

Filter Angle Bracket

Fig. 30 -- Filter Angle Bracket Installation

Right Hood
Side Panel

Filter Angle Bracket

A09692

41

Hood Top Panel

Right Hood
Side Panel

Hood Divider

Left Hood
Side Panel

A09693

Fig. 31 -- Economizer Hood Assembly

674D-- --A

Fig. 32 -- Economizer Hood Installation

Filter Clips

Aluminum
Filter

A09694

A09695

Fig. 33 -- Filter Installation (See Through View)

42

Large Chassis

To install the Vertical Economizer on the large chassis perform the
following procedure:

1. Turn off unit power supply and install lockout tag.

!

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury or death.

Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be more
than one disconnect switch. Turn off accessory heater
power switch if applicable.

2. Remove economizer hood top panel from the return side of
the unit. See Fig. 34. Keep screws and panel next to the
unit.

3. Remove red shipping tape that attaches the outside air
temperature (OAT) sensor to the economizer assembly and
place sensor next to the unit.

4. Remove horizontal return duct cover panel and cut the wire
ties that hold the hood divider to the economizer assembly.
Slide hood divider off from the two slots holding it in place
and place next to the unit. See Fig. 35.

NOTE: Gas units have a flue hood attached to the hood divider.
Unscrew the fastener holding the flue hood in place and dispose
the screw. Follow unit’s literature for flue hood installations.

5. Replace horizontal return duct cover panel. Screw in place
ensuring all seams are air and watertight.

6. Open economizer hood package found on the top skid.
Mount OAT sensor to its assigned bracket by screwing
together with provided two #8 fasteners. Afterwards install
OAT sensor to the right side hood panel with the provided
#10 screws. See Fig. 36.

7. Install the 2 angle filter brackets to the right and left hood
side panels respectively with the #10 screws provided. See
Fig. 37.

8. Assemble hood according to Fig. 38 screwing together with
provided #10 sheet metal screws.

9. Install assembled hood over the economizer opening in the
replacement return chamber panel. See Fig. 39. Screw in
place through pre-punched holes. Make sure all seams are
watertight.

NOTE: The two wires that connect to the outside air temperature
sensor (OAT) should remain accessible.

10. Connect the outside air temperature sensor (OAT) to the
economizer per wiring diagram.

Filter Access
Panel

Hoop Top
Panel

OAT Sensor

A09696

Fig. 34 -- Economizer Hood Top Panel Removal

674D-- --A

Horizontal
Return Duct
Cover Panel

Hood
Divider

Fig. 35 -- Horizontal Return Duct Cover Panel and Hood Divider Removal

Hood Divider
(Removed)

A09697

43

A09698

Fig. 36 -- OAT Bracket Installation

674D-- --A

Left Hood
Side Panel

Filter Angle
Bracket

Filter Angle Bracket

Right Hood
Side Panel

Left Hood Side

Right Hood Side

A09699

Fig. 37 -- Filter Angle Bracket Installation

44

Left Hood
Side Panel

Hood Top Panel

Hood
Divider

Right Hood
Side Panel

Fig. 38 -- Hood Assembly

NOTE: The economizer control settings and the filters are

accessible through the filter access door.

A09700

674D-- --A

A09701

Fig. 39 -- Economizer Hood Installation

11. Open the filter clips on the inside of the hood top. Insert the
aluminum filter into the hood and close the clips to hold in
place. See Fig. 40.

12. T o replace air filters, open filter access door remove old
filters and install new disposable filters in filter rack. See
Table 18 for filter part numbers.

IMPORTANT: On the the bent coil (See Fig. 41 to determine coil
type) filter rack, the 18 x 24x1(257.2mm x 609.6mm x25.4mm)
filter must be installed through the filter access door first then
installthe16x24x1(406.4mm x 609.6mm x 25.4mm) filter.

Table 18 – Filter Part Number

DESCRIPTION PA RT N UM BE R

Straight Indoor

Coil Air Filter

Bent Indoor

Coil Air Filter

14 x 24 x 1

(355.6 x 609.6 x 25.4 mm)

16 x 24 x 1

(406.4 x 609.6 x 25.4 mm)

16 x 24 x 1

(406.4 x 609.6 x 25.4 mm)

18 x 24 x 1

(457.2 x 609.5 x 25.4 mm)

KH01AA314

KH01AA316

KH01AA316

KH01AA318

13. Economizer controls are set to a standard factory setting.
Nevertheless, you can adjust these settings through the filter
access door. Review the settings in the Operation section:

(1.) The standard economizer controller has a factory

setting of “C” for the outdoor air temperature
changeover and 63_F(17_C) for the supply air
(mixed air) temperature sensor. The outdoor air
temperature changeover setting is adjusted on the
sensor by setting the dip switches on the sensor.
The ABCD potentiometer on the economizer
controller should be set to the “D” position.

(2.) The low ambient compressor lockout switch setting

is fixed at 42_F(5.6_C).

(3.) The minimum position for the outdoor air damper

can be configured at the controller. When not using

2

sensor, the DCV Max potentiometer must be

aCO
completely closed (CCW) for the Minimum Posi­tion potentiometer to function correctly.

(4.) Settings for the optional outdoor enthalpy sensor,

indoor enthalpy sensor, and CO

sensor can also be

2

configured at the controller.

14. Replace the filter access panel. Screw in place ensuring all
seams are air and watertight.

15. Install all economizer accessories then power HVAC unit
and test cycle economizer.

45

CONFIGURATION

Economizer Standard Sensors

OUTDOOR AIR TEMPERATURE (OAT) S ENSOR— The

outdoorair temperaturesensor(HH57AC080) is a 10 to 20mAdevice
used to measure the outdoor--air temperature. The outdoor--air
temperature is used to determine when the Economizer can be used
for free cooling. The operating range of temperature measurement is
40 to 100_F (4.4 to 37.8_C).The sensorhas 8 selectable temperature
changeover setpoints. The temperature changeover is set using 3 dip

Filter
Clips

Aluminum
Filter

674D-- --A

A09704

Fig. 40 -- Filter Installation (See through view)

Top filter

Bottom
filter rack

Screw

(Note 4 and 5)

rack

Evaporator
Coil

RIGHT SIDE

switches on the sensor. The ABCD potentiometer on the controller
should be set to the “D” position. See Fig. 44.

SUPPLY AIR TEMPERATURE (SAT) SENSOR—The supply
air temperature sensor is a 3 KΩ thermistor located at the inlet of the
indoor fan. See Fig. 42. The operating range of temperature
measurement is 0_ to 158_F (-- 17.8_ to 70_C). See Table 19 for
sensor temperature/resistance values. The temperature sensor looks
like an eyelet terminal with wires running to it. The sensor is located
in the “crimp end” and is sealed from moisture.

Table 19 – Supply Air Sensor Temperature/Resistance Values

TEMPERATURE

(_F)

--- 2 2 --- 3 0 53,010

--- 4 --- 2 0 29,091

14 --- 1 0 16,590

32 0 9,795

50 10 5,970

68 20 3,747

77 25 3,000

86 30 2,416

104 40 1,597

122 50 1,080

140 60 746

158 70 525

CELSIUS (_C) RESISTANCE (OHMS)

Supply Air Temperature
Sensor (SAT)

BENT COIL

To p f il t er
rack

Bottom
filter rack

STRAIGHT COIL

Fig. 41 -- Indoor Coil with Filter Rack

Evaporator
Coil

A09714

Indoor
Blower

A09707

Fig. 42 -- SAT Location

LOW TEMPERATURE COMPRESSOR LOCKOUT
SWITCH—The Economizer is equipped with a low ambient

temperature lockout switch located in the outdoor airstream which is
used to lock out the compressors below a 42_F(5.6_C) ambient
temperature.

46

Economizer Control Modes

— Determine the Economizer control

mode before set up of the control. Some modes of operation may
require different sensors. Refer to Table 15. The Economizer is
supplied from the factory with a supply air temperature sensor, a low
temperature compressor lockout switch, and an outdoor air temper­ature sensor. This allows for operation of the Economizer with
outdoor air dry bulb changeover control. Additional accessories can
be added to allow for different types of changeover control and
operation of the Economizer and unit.

OUTDOOR DRY BULB CHANGEOVER—The standard
controlleris shipped from the factory configuredforoutdoor dry bulb
changeover control. The outdoor air and supply air temperature
sensors are included as standard.

For this control mode, the outdoor temperature is compared to a

selectable set point on the sensor See Fig. 44. If the outdoor--air

temperature is above the set point, the Economizer will adjust the
outdoor air dampers to minimum position. If the outdoor--air
temperature is below the set point, the position of the outdoor--air
dampers will be controlled to provide free cooling using outdoor
air. When in this mode, the LED next to the free cooling set point
potentiometer will be on. The changeover temperature set point is
set using the switches on the sensor. See Fig. 44 for the
corresponding temperature changeover values.

EXHAUST FAN

SETPOINT

LED LIGHTS WHEN

EXHAUST CONTACT

MINIMUM DAMPER

POSITION SETTING

MAXIMUM DAMPER DEMAND

CONTROL VENTILATION

LED LIGHTS WHEN
DEMAND CONTROL

VENTILATION INPUT

IS ABOVE SETPOINT

DEMAND CONTROL

VENTILATION SETPOINT

LED LIGHTS WHEN

OUTDOOR AIR IS

SUITABLE FOR FREE

IS MADE

SETPOINT

COOLING

CHANGEOVER SETPOINT

ENTHALPY

A09708

Fig. 43 -- Economizer Controller Potentiometer and LED

Locations

OUTDOOR ENTHALPY CHANGEOVER—For enthalpy

control, accessory enthalpy sensor (part number HH57AC078) is
required. Replace the standard outdoor dry bulb temperature sensor
with the accessory enthalpy sensor in the same mounting location.

ECONOMIZER

RETURN AIR
SENSOR

RETURN DUCT
(FIELD-PROVIDED)

A09710

Fig. 45 -- Enthalpy Sensor Mounting Location

CONTROL

CURVE

A 73 (23)

B
C
D

16

14

12

CONTROL POINT

APPROX ˚F (˚C)

AT 50% RH

70 (21)
67 (19)
63 (17)

34

32

30

28

26

ENTHALPY – BTU PER POUND DRY AIR

24

22

20

18

40
(4)

35
(2)

55

(13)

50

C

(10)

45

D

(7)

85

(29)90(32)95(25)

46

44

80

42

40

38

36

65

(18)

60

(16)

A

B

(27)

75

(24)

70

(21)

100

90

80

70

60

50

RELATIVE HUMIDITY (%)

40

30

100

105

110

(38)

(41)

(43)

20

10

674D-- --A

Fig. 44 -- Outdoor Air Temperature Changeover Set Points

(8.9°C)

(11.7°C)

(12.8°C)

(14.4°C)

(17.2°C)

(20°C)

(22.8°C)

(25.6°C)

A10134

47

A

B

C

D

35
(2)40(4)45(7)50(10)55(13)60(16)65(18)70(21)75(24)80(27)85(29)90(32)95(36)

APPROXIMATE DRY BULB TEMPERATURE — ˚F (˚C)

Fig. 46 -- Enthalpy Changeover Setpoints

100

105

110

(38)

(41)

(43)

A09711

6000

IAQ sensor should be wired to the AQ and AQ1 terminals of the
controller. Adjust theDCV potentiometersto correspondto theDCV

5000

voltage output of the indoor air quality sensor at the user determined
set point. SeeFig. 47. If a separate field--supplied transformer is used

4000

3000

2000

1000

0

2 345678

Fig. 47 -- CO2Sensor Maximum Range Setting

800 ppm
900 ppm
1000 ppm
1100 ppm

A09713

to power the IAQ sensor, the sensor must not be grounded or the
Economizer control board will be damaged.

EXHAUST SET POINT ADJUSTMENT—The exhaust setpoint
will determine when the exhaust fan runs based on damper position
(if power exhaust is installed). The set point is modified with the
Exhaust Fan Set Point (EXH SET) potentiometer. See Fig. 49 for
Wiring Diagram. The set point represents the damper position above
which the exhaust fans will be turned on. When there is a call for
exhaust, theEconomizer controllerprovidesa 45 ± 15 second delay
beforeexhaust fan activation to allow thedampersto open. Thisdelay
allows the damper to reach the appropriate position to avoid
unnecessary fan overload.

MINIMUM POSITION CONTROL — There is a minimum

TR TR1

24 Vac

24

COM

Vac

HOT

12

5

43

EF1EF

A09712

EXH

DCV

Free
Cool

EXH

Set

10V

2V

Min
Pos

Open

DCV

Max

10V

2V

DCV

Set

10V

2V

C

B

DA

N1

N

P1

674D-- --A

P

T1

T

AQ+

AQ

SO+

SO

SR+

SR

Fig. 48 -- Economizer Controller

When the outdoor air enthalpy rises above the outdoor enthalpy
changeover set point,the outdoor--airdamper movesto its minimum
position. The outdoor enthalpy changeover set point is set with the
outdoor enthalpy set point potentiometer on the Economizer
controller. The set points are A, B, C, and D. See Fig. 46. The
factory--installed 620--ohm jumper must be in place across terminals
SR and SR+ on the Economizer controller. See Fig. 48 and Fig. 49.

DIFFERENTIAL ENTHALPY CONTROL — For differential
enthalpy control, the Economizer controller uses two enthalpy
sensors (HH57AC078 and CRENTDIF004A00), one in the outside
air and one in the return airstream. The Economizer controller
compares the outdoor air enthalpy to the return air enthalpy to
determine Economizer use. The controller selects the lower enthalpy
air(return or outdoor)for cooling. For example, whenthe outdoorair
has a lower enthalpy than the return airand is below the set point, the
Economizeropensto bring in outdoorair for freecooling.Replacethe
standard outside air dry bulb temperature sensor with the accessory
enthalpy sensor in the same mounting location. Mount the return air
enthalpy sensor in the return air duct. See Fig. 45. When using this
mode of changeover control, turn the enthalpy set point poten­tiometer fully clockwise to the D setting.

INDOOR AIR QUALITY (IAQ) SENSOR INPUT —The IAQ
input can beused fordemand control ventilation control based on the
level of CO

measured in the space or return air duct. Mount the

2

accessory IAQ sensor according to manufacturer specifications. The

damper position potentiometer on the Economizer controller. See
Fig. 43 and Fig. 49. The minimum damper position maintains the
minimumairflowinto the building during theoccupied period.When
using demand ventilation, the minimum damper position represents
the minimum ventilation position for VOC (volatile organic
compound) ventilation requirements. The DCV Max potentiometer
must be fully closed (CCW) to allow the minimum position
potentiometer to function correctly.

When demand ventilation control is not being used, the minimum
position potentiometer should be used to set the occupied ventilation
position. The maximum demand ventilation position should be
turned fully clockwise. Adjust the minimum position potentiometer
to allow the minimum amount of outdoor air, as required by local
codes, to enter the building. Make minimum position adjustments
with at least 10_F (12.2_C) temperature difference between the
outdoor and return--air temperatures. To determine the minimum
position setting, perform the following procedure:

1. Calculate the appropriate mixed air temperature using the
following formula:
(T

x OA/100) + (TRx RA/100) = T

o

M

TO= Outdoor--Air Temperature
OA = Percent of Outdoor Air

= Return--Air Temperature

T

R

RA = Percent of Return Air

= Mixed--Air Temperature

T

M

As an example, if local codes require 10% outdoor air
during occupied conditions, outdoor-- air temperature is
60_F (15.6_C), and return--air temperature is 75_F
(23.9_C). (60 x .10) + (75 x .90) = 73.5_F (23.1_C)

2. Disconnect the supply air sensor from terminals T and T1.

3. Ensure that the factory--installed jumper is in place across
terminals P and P1. If remote damper positioning is being
used, make sure that the terminals are wired according to
Fig. 49 and that the minimum position potentiometer is
turned fully clockwise.

4. Connect 24 vac across terminals TR and TR1.

5. Carefully adjust the minimum position potentiometer until
the measured mixed-- air temperature matches the calculated
value.

6. Reconnect the supply air sensor to terminals T and T1.

Remote control of the Economizer damper is desirable when
requiring additional temporary ventilation. If a field--supplied
remote potentiometer (Honeywell part number S963B1128) is
wired to the Economizer controller, the minimum position of the
damper can be controlled from a remote location. To control the
minimum damper position remotely, remove the factory installed
jumper on the P and P1 terminals on the Economizer controller.
Wire the field--supplied potentiometer to the P and P1 terminals on
the Economizer controller. See Fig. 48 and Fig. 49.

48

674D-- --A

A10059

Fig. 49 -- Economizer Wiring Diagram

49

CONNECTION WIRING DIAGRAM

DANGER: ELECTRICAL SHOCK HAZARD DISCONNECT POWER BEFORE SERVICING

NOTES:

1. IF ANY OF THE ORIGINAL WIRES FURNISHED ARE REPLACED,
THEY MUST BE REPLACED WITH THE SAME WIRE OR ITS EQUIVALENT.

2. SEE PRICE PAGES FOR THERMOSTATS.

3. USE 75 DEG. COPPER CONDUCTORS FOR FIELD INSTALLATION.

4. SEE INSTALLATION INSTRUCTIONS FOR PROPER HEATING AND COOLING
CONNECTIONS FOR YOUR UNIT. INDOOR FAN MOTOR PLUGS

- "DO NOT DISCONNECT UNDER LOAD"

5. THIS FUSE IS MANUFACTURED BY LITTELFUSE, P/N 257003.

6. THIS FUSE IS MANUFACTURED BY LITTELFUSE, P/N 257005.

7. INDUCER CAPACITOR AND WIRING ON CERTAIN MODELS ONLY.
IF CAP2 IS PRESENT, YELLOW WIRES FROM IGC AND IDM CONNECT
ON SAME SIDE OF CAP2.

8. REMOVE YELLOW SPLICE WIRE WHEN ECONOMIZER AND ECONOMIZER
RELAYS ARE USED AND CONNECT TO RELAY R1 AS SHOWN.

9. WHEN ECONOMIZER AND ECONOMIZER RELAYS ARE USED,
CONNECT THE YELLOW AND BLACK WIRES TO RELAY R AS SHOWN. RELAY
KIT REQUIRED WITH ECONOMIZER AND HEAT PUMP/DUAL FUEL UNITS.

10. WHEN ECONOMIZER AND ECONOMIZER RELAYS ARE USED,
INSTALL WIRES AS SHOWN ONTO THE COILS OF RELAY R AND RELAY R1.

11. DEHUMIDIFICATION FEATURE CANNOT BE USED WHEN ECONOMIZER IS
INSTALLED.

FIELD SPLICE
TERMINAL (MARKED)
TERMINAL (UNMARKED)
SPLICE (IF USED)
SPLICE (MARKED)
FACTORY WIRING
FIELD CONTROL WIRING
FIELD POWER WIRING
ACCESSORY OR OPTIONAL
WIRING

C CONTACTOR
CAP 1 CAPACITOR, COMP
CAP 2 CAPACITOR, INDUCER
CCH CRANK CASE HEATER
COMP COMPRESSOR MOTOR
CR COMBUSTION RELAY
DB DEFROST BOARD
DFT DEFROST TEMPERATURE
SWITCH
DH DEHUMIDIFICATION MODE
DR DEFROST BOARD RELAY

ECONOMIZER PLUG

7

674D-- --A

SEE 50SD500625

7

6

6

11

11

10

10

8

8

2

2

3

3

4

4

ECONOMIZER LABEL DIAGRAM

1

1

5

5

9

9

12

12

ECON ECONOMIZER
EQUIP EQUIPMENT
FS FLAME SENSOR
GND GROUND
HPS HIGH PRESSURE SWITCH
I IGNITOR
IGC INTERGRATED GAS UNIT CONTROLLER
IFB INDOOR FAN BOARD
IDM INDUCED DRAFT MOTOR
IFM INDOOR FAN MOTOR
LGPS LOW GAS PRESSURE SWITCH (WHEN USED)
LPS LOW PRESSURE SWITCH
LS1 PRIMARY LIMIT SWITCH
LS2 SECONDARY LIMIT SWITCH
MGV MAIN GAS VALVE
OFM OUTDOOR FAN MOTOR
PRS PRESSURE SWITCH
RS ROLLOUT SWITCH
RVS REVERSING VALVE
SAT SUPPLY AIR TEMPERATURE
TRAN TRANSFORMER
T-STAT THERMOSTAT

R ECON RELAY

R1 ECON RELAY

ECON

BL

P

P

SAT

BL

GY

Y

R

BR

BK

IGC

CR

L1

BL

L2

J2

IFO

GY

W

W

G

5AMP

R

R

FUSE

RS

RS

LS

LS

CS

CS

GV

GV

GROUNDED
THRU STANDOFF

SEE NOTE 9

BK

Y

R

2

1

BK

3

Y

CM

BM

L2

L2

RT

V

V

GVR

FS

C

C

3

1

2

CAP 3

QT

SEE NOTE 6

BL

BL

LGPS (WHEN USED)

LS1

13

Y

O

BR

Y

I

O

R1

SEE NOTE 8

FIELD

SUPPLY

W

R

GY

BK

V

IDM

Y

BR

G/Y

R

RS

13

R

O

M

GY

FS

BR

G/Y

BR

EQUIP_GND

R

13

IF USED

BK

Y

BL

CCH

BK

C

11 21

13

BK

1

23

1

BK

G

COMPRESSOR PLUG

Y

BK

BK

PRIMARY

Y

COM

208/230V

DB

DR

OF1

BK

BK

OF2

BK

Y

CAP1

C

Y

BR

BR

F

BK

T1

T2

BL

Y

T3

BK

Y

BK

G/Y

230

Y

TRAN

SECONDARY

24 V

C

24V

R

BR

R

BR

W

SEE NOTE 5

IFB

GY

W

R

P2

R

R

Y

G

W

DEFROST BOARD (DB)
DR

OF1

OF2

0

W2

R

P1
Y
C

BR

CTD

T-STAT

GY

Y2

R

BR

Y

C

Y1

G

DH

BL

W

O

O

SEE
NOTE 7

LS2

PRS

MGV

C

R

O

W

Y

1

24V

2

C

W

3

R

4

X

5

P1

R

1

2

C

3

Y1/Y

4

G

Y2/DH

5

6

W

Y

Y

SEE NOTE 10

BK

O

BL

T2

BR

C

P2

C

90

UP

6030120

SPEED

P

DFT

P

R

P3

BK

T1

BL

Y

BR

DIP SWITCH SETTINGS

DEFAULT

30 MINUTES

30

11 11133 33322 222

FIELD SELECTABLE OPTIONS FOR
TIME PERIOD BETWEEN DEFROST
CYCLES (MINUTES)

Y

Y

OR

60 MINUTES

60

90 MINUTES

120 MINUTES

OROR

90

Y

FUSE

RVS

DFT

ON

QUIET
SHIFT

OFF

(DEFAULT)

SPEED

UP

1) MOMENTARILY SHORT PINS AND RELEASE TO BYPASS
COMPRESSOR OFF DELAY.

2) SHORT FOR 5+ SEC. AND RELEASE FOR FORCED DEFROST.

3) PERMANENT SHORT WILL BE IGNORED.

DEFROST WILL TERMINATE IN 30 SEC. IF DFT OPEN.
DEFROST WILL TERMINATE NORMALLY IF DFT IS CLOSED.

Fig. 50 -- Connection Wiring Diagram 230--3

SCHEMATIC

208/230-3-60

OFM

COMP

N

G

L

C

BR

3A

COM

HEAT

BR

HPS

JUMPERED TEST PINS (USE METAL OBJECT)
FIELD SPEED-UP CYCLE

IFM

BR

R

C

BR

C

BR

COM

BR

LOW

R

HIGH

GAS

SEE NOTE 11

INDOOR BLOWER
24V CONNECTIONS
SEE NOTE 4

O

C2

C1

R

C2

C1

R1

C2

C1

C

LPS

BL

BK

THE COMPRESSOR WILL SHUT OFF FOR
30 SEC. ON DEFROST INITIATION AND
TERMINATION IN THE "QUIET SHIFT"
ON POSITION.

COLOR CODE

BK BLACK
BL BLUE
BR BROWN
GY GRAY
G GREEN
O ORANGE
P PINK
R RED
V VIOLET
W WHITE
Y YELLOW

BK

W

BR

2435

1

BL

P

R

SEE NOTE 4

BR

BK

O

A10075C

50

LADDER WIRING DIAGRAM

DANGER: ELECTRICAL SHOCK HAZARD DISCONNECT POWER BEFORE SERVICING

3 UNIT COMPONENT ARRANGEMENT

OUTDOOR FAN
SECTION

COMPRESSOR
SECTION

LPS

HPS

COMP

T1

T3

OFM

INDOOR FAN
SECTION

CAP 1

R

CF

IFM

T2

CONTROL BOX AREA

LS1

(LARGE)

LS2

(SMALL)

R1

LS1

(SMALL
CABINET)

23

13

C

IGC

PRS

GAS
SECTION

TRAN

11

21

DB

IFB

CAP 2

IDM

MGV

MC

RS

I

FS

L1

11

11

11

USE COPPER CONDUCTORS ONLY

BK

FIELD SUPPLY

208/230 VAC, 60 HZ, 3PH

21

C

BK

BK

G/Y

CCH

(IF USED)

BK

OF1

BK

DB

DR

BK

OF2

CAP

BK

OFM

BK

C

S

BR

BR

F

C

T2

T1

COMP

IFM

BK

G

Y

R

Y

T3

Y

G/Y

L3

L2

BL

Y

23

Y

BL

Y

C

13

23

T'STAT

R

O

G

W

DH

Y1

C

Y2

IGC

CR

CM

11

L1

BK

V

IDM

G/Y

TRAN

SEE NOTE 5

IFB

24VAC R

FUSE

3A

P2-1"R"

P2-2"C"

P2-5"X"

P2-3"W"

1

R

1

O

1

G

1

W

1

BL

1

Y

P2-4"R"

P1-1"R"

P1-4"G"

P1-6"W"

W

P1-5"Y2/DH"

P1-3"Y1/Y"

R

BR

GY

W

R

IGC

5AMP

RT

FUSE

C

FS

RS

R

Y

BL

SEE NOTE 6

RS

RS

V

LS

LS

CS

CS

GV

IFO

R

LS1 LS2

IF USED

Y

O

O

GY

BK

R

24V

FS

BL

V

PRS

MC

MGV

230

PRIMARY 208/230V

SECONDARY 24V

Y

BR

CAP2

COM

BR

C

DB

P3-1

P3-2

P1-7,R

P1-8,O

O

P1-5,Y

Y

P1-6,W2

W

P2-4

P2-1

P

P

BK

T1

BL

Y

T2

BL

O

BK

BR

W

2

R

SEE NOTE 4

2

Y

3

R

4

5

6

7

8

W

SEE NOTE 8

SEE NOTE 4

Y

R1

2

BR

BK

BL

SAT

BL

1

3

R

Y

3

1

2

BK

BR

SEE NOTE 11

Y

LOW

GY

HIGH

GAS HEAT

Y

BK

O

ECONOMIZER PLUG

3

4

5

6

7

SEE 50SD500625

ECONOMIZER LABEL DIAGRAM

8

48EZ500146

Y

DFT

HPS

BK

C

RVS

SEE NOTE 10

BL

P

R

O

BK

SEE NOTE 9

Y

1
2

35
4

IGC

L2

BL

SEE NOTE 7

LPS

BR

BR

BR

R

R1

IFM

Y

G/Y

BR

COM C

A

23

IFB

COM

IFB
C

DB-C

DB-C

C

C

GV

IGC

IGC

IFB
COM

IFB
P1-2

674D-- --A

C

C

A10075L

Fig. 50 Cont. -- Ladder Wiring Diagram 230--3

51

DAMPER MOVEMENT — Damper movement from full open to
full closed (or vice versa) takes 2 1/2 minutes.

THERMOSTATS — The Economizer control works with conven­tionalthermostats that have aY1 (cool stage 1), Y2 (coolstage2),W1
(heatstage 1), W2 (heatstage2), andG (fan).The Economizercontrol
does not support space temperature sensors. Connections are made at
the thermostat terminal connection board located in the main control
box.

OCCUPANCY CONTROL — The factory default configuration
for the Economizer control is occupied mode. Occupied status is
provided by the black jumperfrom terminalTR to terminal N. When
unoccupied mode is desired, install a field supplied time clock
function inplaceof the jumper between TR and N. SeeFig. 49. When
the timeclock contacts are closed, the Economizer control will be in
occupied mode. Whenthetimeclockcontacts areopen (removingthe
24--v signal from terminal N), the Economizer willbe in unoccupied
mode.

DEMAND CONTROLLED VENTILATION (DCV)—When
using the Economizer for demand controlled ventilation, there are
someequipment selection criteria which should be considered. When
selecting the heat capacity and cool capacity of the equipment, the
maximum ventilation rate must be evaluated for design conditions.

674D-- --A

The maximum damper position must be calculated to provide the
desired fresh air. Typically the maximum ventilation rate will be about
5 to 10% more than the typical CFM required per person, using
normal outside air design criteria. An exponential anticipatory
strategy should be taken with the following conditions: a zone with
a large area,varied occupancy, and equipment that cannot exceed the
required ventilation rate at design conditions. Exceeding the required
ventilation rate means the equipment can condition air at a maximum
ventilation rate that is greater than the required ventilation rate for
maximum occupancy. An exponential--anticipatory strategy will
causethe freshair suppliedto increase as the roomCO
even though the CO
CO

level reaches the set point, the damper will be at maximum

2

set point has not been reached. By the time the

2

level increases

2

ventilation and should maintain the setpoint. In orderto havetheCO
sensorcontrolthe economizerdamper in this manner, first determine
the damper voltage output for minimum or base ventilation. Base
ventilation is the ventilation required to remove contaminants during
unoccupied periods. The following equation may be used to
determine the percent of outside--air entering the building for a given
damper position. For best results there should be at least a 10_F
(12.2_C) difference in outside and return--air temperatures.

(T

x OA/100) + (TRx RA/100) = T

o

M

The DCV set point may be left at 2 volts since the CO
voltage will be ignored by the Economizer controller until it rises
above the 3.6 volt setting of the minimum position potentiometer.
Once the fully occupied damper position has been determined, set
the maximum damper demand control ventilation potentiometer to
this position. Do not set to the maximum position as this can result
in over ventilation to the space and potential high--humidity levels.

SENSOR CONFIGURATION — The CO2sensor has preset

CO

2

standard voltage settings that can be selected anytime after the sensor
is powered up. Use setting 1 or 2 for equipment. See Table 20.

1. Press Clear and Mode buttons. Hold at least 5 seconds until
the sensor enters the Edit mode.

2. Press Mode twice. The STDSET Menu will appear.

3. Use the Up/Down button to select the preset number. See
Table 20.

4. Press Enter to lock in the selection.

5. Press Mode to exit and resume normal operation.

The custom settings of the CO

sensor can be changed anytime

2

after the sensor is energized. Follow the steps below to change the
nonstandard settings:

1. Press Clear and Mode buttons. Hold at least 5 seconds until
the sensor enters the Edit mode.

2. Press Mode twice. The STDSET Menu will appear.

3. Use the Up/Down button to toggle to the NONSTD menu
and press Enter.

4. Use the Up/Down button to toggle through each of the nine
variables, starting with Altitude, until the desired setting is
reached.

5. Press Mode to move through the variables.

6. Press Enter to lock in the selection, then press Mode to
continue to the next variable.

DEHUMIDIFICATION OF FRESH AIR WITH DCV
CONTROL—Information from ASHRAE indicates that the largest

humidity load on any zone is the fresh air introduced. For some
applications, an energy recovery unit can be added to reduce the

2

moisture contentof thefresh air being broughtintothe building when
the enthalpy is high. In most cases, the normal heating and cooling
processes are more than adequate to remove the humidity loads for
most commercial applications.

If normal rooftop heating and cooling operation is not adequate for
the outdoor humidity level, an energy recovery unit and/or a
dehumidification option should be considered.

sensor

2

TO= Outdoor--Air Temperature
OA = Percent of Outdoor Air
T

= Return-- Air Temperature

R

RA = Percent of Return Air
T

= Mixed--Air Temperature

M

Once base ventilation has been determined, set the minimum damper
position potentiometer to the correct position. The same equation can
be used to determine the occupied or maximum ventilation rate to the
building.For example, an output of 3.6 volts to the actuator provides
a base ventilation rate of 5% and an output of 6.7 volts provides the
maximum ventilation rate of 20% (or base plus 15 CFM per person).
Use Fig. 47 to determine the maximum setting of the CO

sensor. For

2

example, a 1100 ppm setpoint relates to a 15 CFM per person design.
Use the 1100 ppm curve on Fig. 47 to find the point when the CO

2

sensor output will be 6.7 volts. Line up the point on the graph with
the left side of the chart to determine that the range configuration for
the CO

sensorshould be 1800 ppm. The Economizercontroller will

2

output the 6.7 voltsfrom the CO

sensorto theactuatorwhen theCO

2

2

concentration in the space is at 1100 ppm.

52

Table20–CO

SETTING EQUIPMENT OUTPUT

1 Proportional Any

2

3 Exponential Any

4 Proportional 15

5 Economizer Proportional 20

6 Exponential 15

7 Exponential 20

8 Health & Safety Proportional ---

9 Parking/Air Intakes/Loading Docks Proportional ---

Interface w /Standard Building

Control System

Proportional Any

Sensor Standard Settings

2

VENTILATION

RATE

(CFM/

PERSON)

ANALOG

OUTPUT

0 --- 1 0 V

4 --- 2 0 m A

2 --- 1 0 V

7 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

0 --- 1 0 V

4 --- 2 0 m A

CO

2

CONTROL

RANGE

(PPM)

0--- 2000 1000 50

0--- 2000 1000 50

0--- 2000 1100 50

0--- 1100 1100 50

0 --- 9 0 0 900 50

1--- 1100 1100 50

0 --- 9 0 0 900 50

0--- 9999 5000 500

0--- 2000 700 50

OPTIONAL

RELAY

SETPOINT

(PPM)

HYSTERESIS

RELAY

(PPM)

Table21–CO2Sensor Standard Settings Economizer Input/Output Logic

INPUTS OUTPUTS

DEMAND

CONTROL

VENTILATION

(DCV)

Below set (DCV

LED Off)

Above set (DCV

LED On)

* For single enthalpy control, the module compares outdoor enthalpy to the ABCD set point.

{Power at N terminal dete rmines Occupied/Uno ccupied setting: 24 va c (Occupied), now power (Unoccupied).

**Modulating is based on the supply---air sensor signal.

{{Modulation is based on the DCV signal.

***Modulation is based on the greater of DCV and supply--- air sensor signals, between minimum position and either maximum position (DCV) or fully open (supply--- ai r signal).

{{{Modulating is based on the greater of DCV and supply---air sensor signals, between closed and wither maximum position (DCV) or fully open (supply--- air signal).

Sequence of Operation—When free cooling is not available, the
compressor will be controlled by the thermostat. When free cooling
is available, the outdoor--air damper is modulated by the Economizer
control to provide a 50_ to 55_F(10_ to 12.8_C) supply--air
temperature into the zone. As the supply--air temperature fluctuates
above 55_ (12.8_C) or below 50_F(10_C), the dampers will be
modulated (open or close) to bring the supply--air temperature back
within the set points. For Economizer operation, there must be a
thermostat call for the fan (G). This will move the damper to its
minimum position during the occupied mode.

NOTE: The DCV Max potentiometer must be colosed (CCW)
when not using CO

Above 50_F(10_C) supply--air temperature, the d ampers will
modulate from 100% open to the minimum open position. From
50_Fto45_F(10_ to 7.2_C) supply--air temperature, the dampers
will maintain at the minimum open position. Below 45_F(7.2_C),
the dampers will be completely shut. As the supply--air temperature

ENTHALPY

OUTDOOR RETURN

High (Free Cooling

LED off)

Low (Free Cooling

LED on)

High (Free Cooling

LED off)

Low (Free Cooling

LED on)

OPERATION

2

sensor.

Low

High

Low

High

COMPRESSOR NTERMINAL

Y1 Y2

On On On On

Off Off Off Off

On On On Off

On Off Off Off

Off Off Off Off Minimum position Closed

On On On On

On Off On Off

Off Off Off Off

On On On Off

Off Off Off Off

STAGE1STAGE

2

OCCUPIED UNOCCUPIED

DAMPER

Minimum position ClosedOn Off On Off

Modulating** (between min.

p o s i ti on a n d f u l l --- o p e n )

Modulating{{ (between

min. position and DCV

maximum)

Modulating*** Modulating{{{On Off Off Off

Modulating** (between closed

Modulating{{ (between closed

a n d f u l l --- o p e n)

and DCV maximum)

exhaust is installed, as the outdoor--air damper opens and closes, the
power exhaust fans will be energized and deenergized. If field -­installed accessory CO

sensors are connected to the Economizer

2

control, a demand controlled ventilation strategy will begin to
operate. As the CO

level in the zone increases above the CO2set

2

point, the minimum position of the damper will be increased
proportionally. As the CO

level decreases because of the increase in

2

fresh air, the outdoor--air damper will be proportionally closed.
Damper position will follow the higher demand condition from DCV
mode or free cooling mode. Damper movement from full closed to
full open (or vice versa) will take between 1 1/2 and 2 1/2 minutes.
If free cooling can be used as determined from the appropriate
changeover command (dry bulb, enthalpy curve, or differential
enthalpy), a call for cooling (Y1 closes at the thermostat) will cause
the control to modulate the dampers open to maintain the supply air
temperature set point at 50_ to 55_F(10_ to 12.8_C). As the supply
air temperature drops below the set point range of 50_ to 55_F(10_
to 12.8_C), the control will modulatethe outdoor--air dampers closed
to maintain the proper supply--air temperature.

rises, the dampers will come back open to the minimum open position
once the supply--air temperature rises to 48_F(8.9_C). If power

674D-- --A

53

TROUBLESHOOTING

See Table 21 for Economizer logic. An Economizer simulator
program is available to help with Economizer training and
troubleshooting.

Economizer Preparation —This procedure is used to prepare the
Economizer for troubleshooting. No troubleshooting or testing is
done by performing the following procedure.

NOTE: This procedure requires a 9--v battery, 1.2 kilo--ohm
resistor, and a 5.6 kilo--ohm resistor which are not supplied with
the Economizer.

1. Disconnect power at TR and TR1. All LEDs should be off.
Exhaust fan contacts should be open.

2. Disconnect device at P and P1.

3. Jumper P to P1.

4. Disconnect wires at T and T1. Place 5.6 kilo--ohm resistor
across T and T1.

5. Jumper TR to 1.

6. Jumper TR to N.

7. If connected, remove sensor from terminals S
Connect 1.2 kilo--ohm 4074EJM checkout resistor across
terminals S

674D-- --A

8. Put 620--ohm resistor across terminals SR and +.

and +.

o

9. Set minimum position, DCV set point, and exhaust poten­tiometers fully CCW (counterclockwise).

10. Set DCV maximum position potentiometer fully CW
(clockwise).

11. Set enthalpy potentiometer to D.

12. Apply power (24 vac) to terminals TR and TR1.

Differential Enthalpy — To check differential enthalpy:

1. Make sure Economizer preparation procedure has been
performed.

2. Place 620--ohm resistor across S

and +.

o

3. Place 1.2 kilo--ohm resistor across SR and +. The Free Cool
LED should be lit.

4. Remove 620--ohm resistor across S

and +. The Free Cool

o

LED should turn off.

5. Return Economizer settings and wiring to normal after
completing troubleshooting.

Single Enthalpy—To check single enthalpy:

1. Make sure Economizer preparation procedure has been
performed.

2. Set the enthalpy potentiometer to A (fully CCW). The Free
Cool LED should be lit.

3. Set the enthalpy potentiometer to D (fully CW). The Free
Cool LED should turn off.

4. Return Economizer settings and wiring to normal after
completing troubleshooting.

DCV (Demand Controlled Ventilation) and Power
Exhaust—To check DCV and Power Exhaust:

1. Make sure Economizer IV preparation procedure has been
performed.

2. Ensure terminals AQ and AQ1 are open. The LED for both
DCV and Exhaust should be off. The actuator should be
fully closed.

3. Connect a 9--v battery to AQ (positive node) and AQ1
(negative node). The LED for both DCV and Exhaust
should turn on. The actuator should drive to between 90
and 95% open.

4. Turn the Exhaust potentiometer CW until the Exhaust LED
turns off. The LED should turn off when the potentiometer

and +.

o

5. Turn the DCV set point potentiometer CW until the DCV
LED turns off. The DCV LED should turn off when the
potentiometer is approximately 9--v. The actuator should
drive fully closed.

6. Turn the DCV and Exhaust potentiometers CCW until the
Exhaust LED turns on. The exhaust contacts will close 30
to 120 seconds after the Exhaust LED turns on.

7. Return Economizer settings and wiring to normal after
completing troubleshooting.

DCV Minimum and Maximum Position —To check the DCV
minimum and maximum position:

1. Make sure Economizer preparation procedure has been
performed.

2. Connect a 9--v battery to AQ (positive node) and AQ1
(negative node). The DCV LED should turn on. The actu­ator should drive to between 90 and 95% open.

3. Turn the DCV maximum position potentiometer to
midpoint. The actuator should drive to between 20 and 80%
open.

4. Turn the DCV maximum position potentiometer to fully
CCW. The actuator should drive fully closed.

5. Turn the Minimum Position potentiometer to midpoint. The
actuator should drive to between 20 and 80% open.

6. Turn the Minimum Position Potentiometer fully CW. The
actuator should drive fully open.

7. Remove the jumper from TR and N. The actuator should
drive fully closed.

8. Return Economizer settings and wiring to normal after
completing troubleshooting.

Supply--Air Input—To check supply--air input:

1. Make sure Economizer preparation procedure has
beenperformed.

2. Set the Enthalpy potentiometer to A. The Free Cool LED
turns on. The actuator should drive to between 20 and 80%
open.

3. Remove the 5.6 kilo--ohm resistor and jumper T to T1. The
actuator should drive fully open.

4. Remove the jumper across T and T1. The actuator should
drive fully closed.

5. Return Economizer settings and wiring to normal after
completing troubleshooting.

Economizer Troubleshooting Completion —This procedure is
used to return the Economizer to operation. No troubleshooting or
testing is done by performing the following procedure.

1. Disconnect power at TR and TR1.

2. Set enthalpy potentiometer to previous setting.

3. Set DCV maximum position potentiometer to previous
setting. Set DVC max potentiometer to fully closed (CCW)
when not using a CO

2

sensor.

4. Set minimum position, DCV set point, and exhaust poten­tiometers to previous settings.

5. Remove 620-- ohm resistor from terminals SR and +.

6. Remove 1.2 kilo--ohm checkout resistor from terminals SO
and +. If used, reconnect sensor from terminals SO and +.

7. Remove jumper from TR to N.

8. Remove jumper from TR to 1.

9. Remove 5.6 kilo--ohm resistor from T and T1. Reconnect
wires at T and T1.

10. Remove jumper from P to P1. Reconnect device at P and
P1.

11. Apply power (24 vac) to terminals TR and TR1.
is approximately 90%. The actuator should remain in
position.

54

REQUIRED CLEARANCES TO COMBUSTIBLE MATL.

NEC. REQUIRED CLEARANCES

REQUIRED CLEARANCE FOR OPERATION AND SERVICING

674D-- --A

A10220

Fig. 51 -- 674D-- -- A 30 -- 36 3 Phase with Economizer

55

REQUIRED CLEARANCES TO COMBUSTIBLE MATL.

NEC. REQUIRED CLEARANCES

REQUIRED CLEARANCE FOR OPERATION AND SERVICING

674D-- --A

Fig. 52 -- 674D-- -- A 42 -- 60 3 Phase with Economizer

E2010 Bryant Heating & Cooling Systems D 7310 W. Morris St. D Indianapolis, IN 46231 Edition Date: 04/10

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurri ng obligations.

56

A10221

Catalog No. II674D---07

Replaces: II674D--- 06