Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical components. Only trained and qualified service personnel should
install, repair, or service a ir-conditioning equip ment.
Untrained personnel can perform the basic maintenance
functions of cl eaning coils and filters a nd replacing filters.
All other operations should be performed by trained service
personnel. When working on air-conditioning equipment,
observe precautions in the literature, tags and labels
attached to the unit, and other safety precautions that may
apply.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire
extinguishers available for all brazing opera tions.
WARNING: Before performing service or maintenance operations on unit, turn off main power switch
to unit. Electrical shock could cause personal injury.
WARNING:
1. Improper installation, adjustment, alteration,
service, or maintenance can cause property
damage, personal injury, or loss of life. Refer to
the User’s Information Manual provided with
this unit for more details.
2. Do not store or u se ga sol ine or o th er fl amm able
vapors and liquids in the vicinity o f this or any
other appliance.
What to do if yo u sm ell gas:
1. DO NOT try to light any appliance.
2. DO NOT touch an y electrical switch, or use any
phone in your building.
3. IMMEDIATELY call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
4. If you cannot reach your gas supplier, call the
fire department.
WARNING: Disconnect gas piping from unit when
pressure testing at pressure greater than 0.5 psig.
Pressures greater than 0.5 psig will cause gas valve
damage resulting in hazardous c ondition. If gas valve
is subjected to pressure greater than 0.5 psig, it must
be replaced before use. When pressure testing fieldsupplied gas piping at pressures of 0.5 psig or less, a
unit connected to such piping must be isolated by closing the manual gas valve(s).
IMPORTANT: Units have high ambient temperature operating limits. If limits are exceeded, the units will automatically
lock the compressor out of oper ation. Manual reset will be
required to restart the compressor.
INSTALLATION
I. STEP 1 — PROVIDE UNIT SUPPORT
A. Roof Curb
Assemble or install accessory roof curb in accordance with
instructions shipped with this accessory. See Fig. 1. Install
insulation, cant strips, roofing, and counter flashing as
shown. Ductwork can be installed to roof curb before unit is
set in place. Ductwork must be attached to curb and not to
the unit. Curb m u st be le v el . T h is is ne ce ssary to permit un it
drain to function properly. Unit leveling tolerance is ±
per linear ft in any direction. Re fer to Accessory Roof Curb
Installation Instructions for additional information as
required. When accessory roof curb is used, unit may be
installed on class A, B, or C roof covering materia l. Bryant
roof curb accessories are for flat roofs or slab mounting.
1
/16 in.
IMPORTANT: The gasketing of the unit to the roof curb is
critical for a watertight seal. Install gasket with the roof
curb as shown in Fig. 1. Improperly applied gasket can also
result in air leaks and poor unit performance. Do not slide
unit to position on roof curb.
B. Alternate Unit Support
When a curb cannot be used, install unit on a noncombustible surface. Support unit with sleepers, using unit curb
support area. If sleepers cannot be used, support long sides
of unit with a minimum of 3 equally spaced 4-in. x 4-in. pads
on each side.
C. Slab Mount (Horizontal Units Only)
Provide a level concrete slab tha t extends a min imum of 6 in.
beyond uni t cabinet. Ins tall a gravel apr on in front of condenser coil air inlet to prevent grass and foliage from
obstructing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
II. STEP 2 — REMOVE SHIPPING RAILS
Remove shipping rails prior to lowering unit onto roof curb.
See Fig. 2. The rails are attached to the unit at both the
return end and c ondenser end. Remove the screws from both
ends of each rail. B e careful not to drop the rails o nto any
surface that could be damaged. Discard the rails. It is important to replace the screws into the unit to avoid any air or
water leakage.
CAUTION: Do not allow the shipping rail to drop
on the roof surface. Damage to the roof surface may
result.
III. STEP 3 — RIG AND PLACE UNIT
Inspect unit for transportation damage. See Tables 1-3 for
physical data. File any claim with transportation agency.
Four lifting holes are provided in the unit base rails as
shown in Fig. 3. Refer to rigging inst ructions on unit.
A. Positioning
Maintain clearance, per Fig. 4, aroun d and abo ve u nit to provide minimum distance from combustible materials, proper
airflow, and service access.
Do not install unit in an indoor location. Do not locate air
inlets near exhaust vents or other sources of contaminated
air. For proper unit operation, adeq uate com bustion and ventilation air must be provided in accordance with Section 5.3
(Air for Combustion and Ventilation) of the National
Fuel Gas Code, ANSI Z223.1 (American National Standards
Institute).
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
Locate mechanical draft system flue assembly at least 4 ft
from any opening through which combustion products could
enter the buil ding, and at le ast 4 ft fr om any adj acen t buil ding (or per local codes). When unit is lo cated adjacent to public walkwa ys , flue as sembly must be at l east 7 ft a bove g rade .
B. Roof Mount
Check building codes for weight distribution requirements.
Unit operating weight is shown in Table 1.
C. Installation Onto Curb
The 581A units are designed to fit on the accessory full
perimeter curb. Correct placement of the unit onto the curb
is critical to op erating performance. To aid in correct positioning,
3
/8-in. diameter locating holes have been added to
the unit base rails. When placing the unit, these holes should
line up with the roof curb edge as shown in Fig. 5 and 6, to
assure proper du ct ope nin g a lign men t. For placement o n the
roof curb, use the alignment holes located approximately
2-in. from the e nd of the base r ail on the return e nd of the
unit. See labels on the side of the unit for more details.
CAUTION: All panels must be in place when rigging. Unit is not designed for handling by fork truck.
Damage to unit may result.
Do not drop unit; keep upr ight. Use sprea der bars over unit
to prevent sling or cable damage. Rollers may be used to
move unit across a roof. Level by using unit frame a s a reference; leveling tolerance is ±
1
/16 in. per linear ft in a ny di re ction. See Fig. 3 for additional information. Unit rigging
weight is shown in Fig. 3.
CAUTION: Do not slide unit to position it when it
is sitting on the curb. Curb gasketing material may be
damaged and leaks may result.
Gas Input (Btuh) HIGH HEATStage 1317,000317,000317,000
Efficiency (Steady State) %Vertical828282
Stage 2400,000400,000400,000
Temperature Rise Range (F)25-5525-5525-55
Gas Input (Btuh) MEDIUM HEATStage 1281,000281,000281,000
Efficiency (Steady State) %Vertical818181
Stage 2365,000365,000365,000
Temperature Rise Range (F)25-5525-5525-55
Gas Input (Btuh) LOW HEATStage 1199,000199,000199,000
Efficiency (Steady State) %Vertical828282
Stage 2250,000250,000250,000
Temperature Rise Range (F)15-4515-4515-45
Manifold Pressure
Natural Gas (in. wg)Vertical3.003.003.00
Natural Gas (in. wg)Horizontal2.952.952.95
Gas Valve Quantity111
Gas Valve Pressure Range(in. wg)5.5-13.05.5-13.05.5-13.0
Min-Max Allowable(psig).235-.469.235-.469.235-.469
Field Gas Connection Size (in. FPT)
HIGH-PRESSURE SWITCH (psig)
Cutout426426426
Reset (Auto)320320320
OUTDOOR-AIR INLET SCREENS
Quantity...Size (in.)3...20x253...20x253...20x25
RETURN-AIR FILTERS
Quantity...Size (in.)9...16x259...16x259...18x24
LEGEND*Aluminum evaporator coil and aluminum condenser coil.
N/A — Not Applicable
TXV — Thermostatic Expansion Valve
1
/4...1100
3
/
4
1
/4...1100
3
/
4
1
/4...1100
3
/
4
—6—
Table 2 — Fan Motor and Drive Data — Vertical Supply/Return
581A
208/230
and 460 v
575 v
208/230
and 460 v
575 v
208/230
and 460 v
575 v
LOW RANGE
210240300
Motor Hp3.73557.57.5
Motor Nominal Rpm172517251745174517451745
Maximum Continuous Bhp4.253.455.755.758.638.63
Maximum Continuous Watts369831494900490072677267
Motor Frame Size56HZ56HZS184T184TS213TS213T
Motor Shaft Diameter (in.)
Fan Rpm Range647-886810-1072949-1206949-1206941-1176941-1176
Motor Pulley Min. Pitch Diameter (in.)2.73.13.73.74.84.8
7
/
8
7
/
8
11/
8
11/
8
13/
8
13/
8
Motor Pulley Max. Pitch Diameter (in.)3.74.14.74.76.06.0
Blower Pulley Pitch Diameter (in.)7.26.66.86.88.98.9
Blower Pulley Shaft Diameter (in.)1.18751.18751.18751.18751.18751.1875
Blower Pulley TypeFixedFixedFixedFixedFixedFixed
Pulley Center Line Distance (in.)11.293-13.544 11.286-14.475 9.81-13.0559.81-13.055 9.025-12.179 9.025-12.179
Belt, Quantity...Type...Length (in.)1...BX...381...BX...381...BX...381...BX...381...BX...421...BX...42
Speed Change Per Turn — Moveable Pulley (rpm)485251514747
Moveable Pulley Maximum Full Turns6 6 6666
Factory Speed Setting (rpm)7679411078107810591059
HIGH RANGE
Motor Hp
Motor Nominal Rpm174517451745174517451745
Maximum Continuous Bhp
Maximum Continuous Watts
Motor Frame SizeS184T184TS213TS213TS215TS215T
Motor Shaft Diameter (in.)
Fan Rpm Range
Motor Pulley Min. Pitch Diameter (in.)3.73.74.84.84.34.3
Motor Pulley Max. Pitch Diameter (in.)
Blower Pulley Pitch Diameter (in.)
Blower Pulley Shaft Diameter (in.)1.18751.18751.18751.18751.18751.1875
Blower Pulley Type
Pulley Center Line Distance (in.)
Belt, Quantity...Type...Length (in.)1...BX...381...BX...381...BX...421...BX...422...BX...382...BX...38
Speed Change per Turn — Moveable Pulley (rpm)
Moveable Pulley Maximum Full Turns
Factory Speed Setting (rpm)10189911059105911561156
Table 3 — Fan Motor and Drive Data — Horizontal Supply/Return
581A
208/230
and 460 v
575 v
208/230
and 460 v
575 v
208/230
and 460 v
575 v
LOW RANGE
210240300
Motor Hp3.73557.57.5
Motor Nominal Rpm172517251745174517451745
Maximum Continuous Bhp4.253.455.755.758.638.63
Maximum Continuous Watts369831494900490072677267
Motor Frame Size56HZ56HZS184T184TS213TS213T
Motor Shaft Diameter (in.)
Fan Rpm Range896-1227863-11411113-14141113-1414941-1176941-1176
Motor Pulley Min. Pitch Diameter (in.)2.73.13.73.74.84.8
7
/
8
7
/
8
11/
8
11/
8
13/
8
13/
8
Motor Pulley Max. Pitch Diameter (in.)3.74.14.74.76.06.0
Blower Pulley Pitch Diameter (in.)5.26.25.85.88.98.9
Blower Pulley Shaft Diameter (in.)1.18751.18751.18751.18751.18751.1875
Blower Pulley TypeFixedFixedFixedFixedFixedFixed
Pulley Center Line Distance (in.)11.293-13.544 11.286-14.475 9.81-13.0559.81-13.055 9.025-12.179 9.025-12.179
Belt, Quantity...Type...Length (in.)1...BX...351...BX...381...BX...351...BX...351...BX...421...BX...42
Speed Change Per Turn — Moveable Pulley (rpm)665660604747
Moveable Pulley Maximum Full Turns6 6 6666
Factory Speed Setting (rpm)106210021264126410591059
HIGH RANGE
Motor Hp
Motor Nominal Rpm174517451745174517451745
Maximum Continuous Bhp
Maximum Continuous Watts
Motor Frame SizeS184T184TS213TS213TS215TS215T
Motor Shaft Diameter (in.)
Fan Rpm Range
Motor Pulley Min. Pitch Diameter (in.)3.74.35.45.44.34.3
Motor Pulley Max. Pitch Diameter (in.)
Blower Pulley Pitch Diameter (in.)
Blower Pulley Shaft Diameter (in.)1.18751.18751.18751.18751.18751.1875
Blower Pulley Type
Pulley Center Line Distance (in.)
Belt, Quantity...Type...Length (in.)1...BX...351...BX...381...BX...421...BX...421...BX...381...BX...38
Speed Change per Turn — Moveable Pulley (rpm)
Moveable Pulley Maximum Full Turns
Factory Speed Setting (rpm)126411641218121811561156
WARNING: For vertical supply and return units,
tools or parts could drop into ductwork and cause an
injury. Insta ll a 90-de gree t urn in th e return ductwor k
between the unit and the conditioned space. If a
90-degree elbow cannot be installed, then a grille of
sufficient strength and density should be installed to
prevent objects from falling into the conditioned space.
EDGE FLANGE
Fig. 5 — Alignment Hole Details
SUPPLY
OPENING
CURB
SUPPLY
OPENING
ALIGNMENT
HOLES FOR
CURB-BOTH
SIDES
RETURN
OPENING
CURB
RETURN
OPENING
ROOF CURB
Fig. 6 — Alignment Hole Location
IV. STEP 4 — FIELD FABRICATE DUCTWORK
On vertical units, secure all ducts to roof curb and building
structure. Do not connect ductwork to unit. For hori zont al
applications, field-supplied flanges should be attached to
horizontal discharge openings and all ductwork 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.
A minimum clearance is not required around ductwork. Cabinet return-air static pressure (a negative condition) shall
not exceed 0.35 in. wg with economizer or 0.45 in. wg without economizer.
These units are designed for a minimum continuous returnair temperature in heating of 50 F (dry bu lb), or an int e rmittent operati on down to 45 F (dry bulb), suc h as when used
with a night set-back thermostat.
To operate at lower return-air temperatures, a field-supplied
outdoor-air temperature control must be used to initiate both
stages of heat when the temperature is below 45 F. Indoor
comfort may be compromised when these lower air temperatures are used with insufficient heating temperature rise.
V. STEP 5 — MAKE UNIT DUCT CONNECTIONS
A. Vertical Configuration
Unit is shipped for vertical supply and return duct connections. Ductwork openings are shown in Fig. 1 and 4. Duct
connections for vertical configuration are shown in Fig. 7.
Field-fabricated concentric ductwork may be connected as
shown in Fig. 8 and 9. The unit is designed to attach the
ductwork to the roof curb. Do not attach duct directly to the
unit.
B. Horizontal Applications
Horizontal units are shipped with outer panels that allow for
side by side horizontal duct connections. If specified during
ordering, the unit will be shipped with the vertical duct
openings blocked of f from the factory, ready for side suppl y
installation. If the horizontal supply/return option was not
specified at time of ordering th e unit, a fiel d-inst alled ac cessory kit is required to convert the vertical unit into a horizontal supply configuration.
Installation of the duct block-off covers should be completed
prior to placing the unit unless sufficient side clearance is
available. A minimum of 66 in. is required between the unit
and any obstruction to install the duct block-off cover s. Side
supply duct dimensions and locations are shown on Fig. 4.
Install ductwork to horizontal duct flange connections on
side of unit.
ECONOMIZER
SEE
NOTE
AIR
IN
NOTE: Do not drill in this area; damage to basepan may result in wate
leak.
SEE
NOTE
HEAT
EXCHANGER
AIR
OUT
Fig. 7 — Air Distribution — Vertical Supply/Return
ECONOMIZER
HEAT
AIR OUT
SEE
NOTE
EXCHANGER
SEE
NOTE
AIR OUT
NOTE: Do not drill in this area; damage to basepan may result in water
leak.
AIR IN
Fig. 8 — Air Distribution — Concentric Duct
—9—
NOTE: Dimensions A, A′, B, and B′ are obtained from field-supplied
ceiling diffuser.
Shaded areas indicate block-off pans.
Fig. 9 — Concentric Duct Details
VI. STEP 6 — INSTALL FLUE HOOD AND INLET HOOD
Flue hood (smaller hood), inlet hood (larger hood), and
screens are shipped inside the unit in the fan section. To
install, remove the heat panel. The flue hood is attached to
the heat section panel from the ou tside usi ng the scre ws pr ovided. See Fig. 10.
The inlet h oo d is i nst a lle d by in s er tin g the h oo d t hro ug h the
back of the heat panel. Attach the hood by inserting the
screws provided through the clearance holes in the heat
panel and into the intake hood.
Install the screens into both hoods using the screws and
retaining nuts provided with the unit.
Attach the cover of the observation hole o n the intake hood
and then replace the heat panel onto the unit to complete the
installation.
NOTE: When properly installed, the flue hood will line up
with the combustion fan housing. See Fig. 11.
VII. STEP 7 — TRAP CONDENSATE DRAIN
See Fig. 12 for drain location. One
3
/4-in. half coupling is provided outside unit evaporator section for condensate drain
connection. A trap at least 4-in. deep must be used. See
Fig. 13.
All units must have an external trap for condensate drainage. Install a trap at least 4 in. deep and protect against
freeze-up. If drain line is installed downstream from the
external trap, pitch the line away from the unit at 1 in. per
10 ft of run. Do not use a pipe size smaller than the unit
connection.
VIII. STEP 8 — INSTALL GAS PIPING
Unit is equipped for use with natural gas. Refer to local
building codes, or in the absence of local codes, to ANSI
(American National Standards Institute) Z223.1-latest year
and addendum Z223.1A-latest year entitled NFGC. In Canada, installation must be in accordance with the
CAN1.B149.1 and CAN1.B149.2 installation codes for gas
burning appliances.
Support gas piping. F or example , a
3
/4-in. gas pipe must have
one field-fabr icated support beam every 8 ft. Therefore, an
18-ft long gas pipe would have a minimum of 3 support
beams.
Install field-supplied manual gas shutoff valve with a
1
/
-in. NPT pressure tap for test gage connection at unit. The
8
pressure tap is located on the gas manifold, adjacent to the
gas valve. Field gas piping must include sediment trap and
union. See Fig. 14.
FLUE HOOD
INLET HOOD
Fig. 10 — Flue and Inlet Hood Locations
COMBUSTION
FAN HOUSING
HEAT
EXCHANGER
SECTION
INDUCED-DRAFT
MOTOR
MAIN BURNER
SECTION
Fig. 11 — Combustion Fan Housing Location
—10—
WARNING: Do not pressure test gas supply while
connected to unit. Always disconnect union before servicing. A hazardous condition could occu r resulting in
serious injury.
IMPORTANT: Natural gas pressure at unit gas connection
must not be less than 5.5 in. wg or greater than 13.0 in. wg.
Size gas-supply piping for 0.5-in. wg maximum pressure
drop. Do not use supply pipe smaller than unit gas
connection.
Fig. 12 — Condensate Drain Details
IX. STEP 9 — MAKE ELECTRICAL CONNECTIONS
A. Field Power Supply
Unit is factory wired for voltage shown on unit nameplate.
Be sure to check for correct voltage.
When installi ng u nit s, provide disconnect per NEC (N ati ona l
Electrical Code) of adequate size (MOCP [Maximum Overcurrent protection ] of unit is on the infor mative plate). See
Tables 4A and 4B. All field wi ring must comply with NEC
and local codes. Size wire based on MCA (Minimum Circuit
Amps) on the unit infor mative plate. See Fig. 15 for power
wiring connection to the unit power terminal block and
equipment ground.
Route power and ground lines through control box end panel
or unit basepan (see Fig. 4) to connections as shown on unit
wiring diagram and Fig. 15.
CAUTION: The correct power phasing is critical to
the operation of the scroll compressors. An incorrect
phasing will resu lt i n com pre ssor shut down on th erma l
overload and possible damage to compressor. Should
this occur, power phase correction must be made to the
incoming power.
WARNING: Unit cabinet must have an uninterrupted, unbroken electrical ground to minimize the
possibility of personal injury if an electrical fault
should occur. This ground may consist of electrical wire
connected to unit ground lug in control compartment,
or conduit approved for electrical ground when
installed in accordance with NEC, ANSI/NFPA
(National Fire Protection Association), latest edition,
and local electrical codes. Do not use gas piping as anelectrical ground. Failure to follow this warning could
result in the install er being liable for pers onal inj ury of
others.
NOTE: Trap should be deep enough to offset maximum unit static difference. A 4-in. trap is recommended.
Fig. 13 — Condensate Drain Piping Details
Field wiring must conform to temperature limitations for
type “T” wire. All field wiring must comply with NEC and
local requirements.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, voltages between phases must be balanced within 2%.
Unit failure as a res ult of ope ra tio n o n imp ro per line volt age
or excessive phase imbalance constitutes abuse and may
cause damage to electrical components.
B. Field Control Wiring
Unit must be controlled with a Bryant-approved accessory
thermostat. Install thermostat according to the installation
instructions included with accessory. Locate thermostat
assembly on a solid interior wall in the conditioned space to
sense average temperature.
Route thermostat cable or equivalent single leads of colored
wire from subbase terminals through conduit into unit to
low-voltage connections as shown on unit label wiring diagram and in Fig. 16.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (American
Wire Gage) insulated wire (35 C minimum). For 50 to 75 ft,
use no. 16 AWG insulated wire (35 C minimum). For over
75 ft, use no. 14 AWG insulated wire (35 C minimum). All
wire larger than no. 18 AWG cannot be directly connected a t
the thermos tat and wi ll req uire a j unction box and s plice a t
the thermostat.
Settings may be changed slightly to provide a greater degree
of comfort for a particular installation.
X. STEP 10 — INSTALL OUTDOOR-AIR HOOD
Perform the following procedure to install the outdoor-air
hood on units equipped with an economizer, two-position
damper, or manual outdoor air damper:
1. Remove blank panel from return end of unit (hood
section). Save the screws. See Fig. 17 for shipping
location of compo n en ts.
2. Hood sides a re fastened to s ides of outdoo r air opening. Remove the hood sides and save the screws
(3 each side).
3. Remove the bracket holding the bottom half of the
hood in the shipping position. Remove the hood bottom half and filters (or manual dampers on units so
equipped) from outdoor section.
NOTE: On units without economizers, the components are attached to the unit basepan. To access the
components, remove the panel below the outdoor air
intake section.
4. Remove inner filter track from shipping position in
outdoor section. Position inner filter track so the
track is facing outward from the unit. Install the filter track with 4 screws provided.
5. Apply seal strip (provided) to back flange of both hood
sides where hood side connec ts to the uni t bac k panel .
See Fig. 18.
6. Apply seal strip (provided) to top flange of both hood
sides where hood sid es connect to the hood top panels. See Fig. 18.
7. Install hood sides to the bac k pane ls using the screws
from Step 2. The sloped flanges point outward. The
drip edges of the side panels should face outward as
well. Attach the filter guides to the hood sides. The
flanges of the filter guides should face inward to hold
the filters in place. See Fi g. 18.
8. Apply seal strip along the enti re lengt h of the bottom
flange of the hood top. See Fig. 18.
9. Install the bottom part of the hood top using 4 screws
provided. See Fi g. 18.
10. Remove the packaging from filters (3) and install into
the filter tracks. Slide the filters to the sides then
place the last filter into the center of the f ilter track.
NOTE: For units with manual dampers, replace the
end filters with the manual dampers. Install the filter
in the center bet w een the manual da mpers.
11. Insta ll the fil ter re ta iner track al ong th e bo ttom ed ge
of the outdoor air ho od using 4 screws prov ided. See
Fig. 18.
12. Install top section of the outdoor air hood using
9 screws provided. See Fig. 18. See Fig. 19 for a picture of the assembled outdoor air hood.
NOTE: For filter removal, remo ve the fou r scre ws ho ldin g th e
filter retainer. The filters can then be rem oved, cleaned, or
replaced. Install th e filters by reversing the procedure.
A. Manual Damper Assembly
For units equipped with manual dampers, the assembly process is similar to the outdoo r air hood for units with econ omizers. The r e ar e tw o slide dampers shi pp ed w it h t h e unit to
allow for manual setting of the outside air volume. When
assembling th e h ood, plac e on e of the manu al sl ide d amp ers
in each of the end positions and the remaining filter in the
center position. The manual dampers can then be moved to
the appropriate position and then locked into place using the
screws mounted in the adjustment slots. See Fig. 20.
HOOD TOP
(TOP HALF)
HOOD
SIDE
RETURN AIR
SECTION
HOOD
SIDE
HOOD TOP
(BOTTOM HALF)
Fig. 17 — Outdoor-Air Hood Component
Shipping Location
—12—
Table 4A — Electrical Data — Units Without Convenience Outlet
FLA— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM— Indoor (Evaporator) Fan Motor
LRA— Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC— National Electrical Code
OFM — Outdoor (Condenser) Fan Motor
RLA— Rated Load Amps
*Fuse or HACR circuit breaker.
NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. Canadian units may be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%.
Use the following formula to determine the percent voltage imbalance.
% Voltage Imbalance
= 100 x
VOLTAGE
(3 Ph,
RANGE
Min Max RLA LRA RLA LRA RLA LRA Qty Hp
460414 506970970 10.79040.25 0.7
575518 6337557559.37340.25 0.7
460414 506 10.790 10.790 10.79040.25 0.7
575518 6339.3739.3739.3734 0.250.7
460414 506 19.6 125 19.6 125——6 0.25 0.7
575518 633 15.8 100 15.8 100——6 0.25 0.7
max voltage deviation from average voltage
average voltage
COMPRESSOR
No. 1No. 2No. 3
OFMIFM
FLA
HpFLAQty Hp
(ea)
3.7 10.6/ 9.6
5 16.7/15.2
3.74.8
57.6
33.9
56.1
5 16.7/15.2
7.524.2/22
57.6
7.511
56.1
7.59
7.524.2/22
1030.8/28
7.511
1014
7.59
1011
3. The convenience outlet full load amps (FLA) are 5, 3, and 3 for 208/230, 460,
POWER
EXHAUST
—— —
215.990/ 89 100/10097/ 96
— ——84/ 83 100/10090/ 89
215.996/ 94 100/100104/102
—— —
213.1455049
—— —425045
213.1485052
—— —
212.4374540
—— —354037
212.4394543
—— —
215.9107/106 125/125117/115
— ——103/101 125/110112/109
215.9115/113 125/125126/123
—— —
213.1516056
—— —495053
213.1556060
—— —
212.4445048
—— —425046
212.4475051
—— —
215.9151/149 175/175160/158
— ——146/143 175/175154/151
215.9158/155 200/200168/164
—— —
213.1668070
—— —628066
213.1698073
—— —
212.4546057
—— —516054
212.4566059
EXAMPLE: Supply voltage is 460-3-60.
Determine maximum deviation from average voltage.
(AB) 457 - 452 = 5 v
(BC) 464 - 457 = 7 v
(AC) 457 - 455 = 2 v
Maximum deviation is 7 v.
Determine percent voltage imbalance.
% Voltage Imbalance = 100 x
This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact the
local electric utility company immediately.
575-V units, respectively.
COMBUSTION
FAN MOTOR
FLA
(ea)
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
FLAMCAMOCP*FLA
0.5
0.3
0.24
0.5
0.3
0.24
0.5
0.3
0.24
7
= 1.53%
457
POWER SUPPLY
78/ 77 100/ 9083/ 82
394542
324035
96/ 94 100/100103/102
455049
394542
139/137 175/175147/144
596063
496052
452 + 464 + 455
3
1371
=
3
=457
DISCONNECT
SIZE
—13—
Table 4B — Electrical Data — Units With Optional Convenience Outlet
FLA— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM— Indoor (Evaporator) Fan Motor
LRA— Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC— National Electrical Code
OFM — Outdoor (Condenser) Fan Motor
RLA— Rated Load Amps
*Fuse or HACR circuit breaker.
NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. Canadian units may be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%.
% Voltage Imbalance
= 100 x
VO LTAGE
(3 Ph,
Use the following formula to determine the percent voltage imbalance.
RANGE
Min Max RLA LRA RLA LRA RLA LRA Qty Hp
460414 506970970 10.79040.25 0.7
575518 6337557559.37340.25 0.7
460414 506 10.790 10.790 10.79040.25 0.7
575518 633 9.3739.3739.37340.25 0.7
460414 506 19.6 125 19.6 125——6 0.25 0.7
575518 633 15.8 100 15.8 100——6 0.25 0.7
max voltage deviation from average voltage
average voltage
COMPRESSOR
No. 1No. 2No. 3
OFMIFM
FLA
HpFLAQty Hp
(ea)
3.7 10.6/ 9.6
5 16.7/15.2
3.74.8
57.6
33.9
56.1
5 16.7/15.2
7.524.2/22
57.6
7.511
56.1
7.59
7.524.2/22
1030.8/28
7.511
1014
7.59
1011
3. The convenience outlet full load amps (FLA) are 5, 3, and 3 for 208/230, 460,
POWER
EXHAUST
—— —
215.995/ 94 100/100103/101
— ——89/ 88 100/10096/ 94
215.9101/ 99 110/100110/108
—— —
213.1485052
—— —455048
213.1516056
—— —
212.4404543
—— —384540
212.4425046
—— —
215.9112/111 125/125123/121
— ——108/106 125/125118/115
215.9120/118 125/125131/129
—— —
213.1546059
—— —526056
213.1586063
—— —
212.4475051
—— —455049
212.4505055
—— —
215.9156/154 200/200166/163
— ——151/148 175/175160/157
215.9163/160 200/200173/170
—— —
213.1698073
—— —658069
213.1729077
—— —
212.4576060
—— —546057
212.4596063
EXAMPLE: Supply voltage is 460-3-60.
Determine maximum deviation from average voltage.
(AB) 457 - 452 = 5 v
(BC) 464 - 457 = 7 v
(AC) 457 - 455 = 2 v
Maximum deviation is 7 v.
Determine percent voltage imbalance.
% Voltage Imbalance = 100 x
This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact the
local electric utility company immediately.
575-V units, respectively.
COMBUSTION
FAN MOTOR
FLA
(ea)
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
FLAMCAMOCP*FLA
0.5
0.3
0.24
0.5
0.3
0.24
0.5
0.3
0.24
7
= 1.53%
457
POWER SUPPLY
83/ 82 100/10089/ 88
425045
354038
101/ 99 110/100109/107
485052
425046
144/142 175/175152/150
628066
526055
452 + 464 + 455
3
1371
=
3
=457
DISCONNECT
SIZE
—14—
SEAL
STRIP
LOCATION
BOTTOM
HOOD
SECTION
TOP HOOD
SECTION
FILTER
RETAINER
FILTER
GUIDE
HOOD
SIDE
FILTER
ADD
SEAL
STRIP
ADD
SEAL
STRIP
INNER
FILTER
TRACK
FILTER
GUIDE
ADD
SEAL
STRIP
ADD
SEAL
STRIP
MANUAL
DAMPER
(IF EQUIPPED)
NOTE: Units with manual damper only use one filter.
Fig. 18 — Outdoor-Air Hood Details
MOVEABLE DAMPER
AIR FILTER POSITION
Fig. 20 — Manual Damper Details
HOOD
SIDE
UNIT
BACK
PANEL
LOCKING SCREW
MOVEABLE DAMPER
Fig. 19 — Outdoor-Air Hood Assembled
—15—
XI. STEP 11 — POSITION OPTIONAL POWER EXHAUST
OR BAROMETRIC RELIEF DAMPER HOOD
The optional p o we r exhaust or barometric re lief dampers are
shipped assembled and tilted back into the unit for shipping.
Brackets and extra screws are shipped in shrink wrap
around the dampers.
1. Remove 9 screws holding each damper assembly in
place. See Fig. 21. Each damper assembly is secured
with 3 screws on each side and 3 screws along the
bottom. Save screws.
CAUTION: Be careful when tilting blower assembly. Hoods and bl ow ers ar e heav y and ca n ca use i nj ur y
if dropped.
2. Pivot the damper assembly outward until top edge of
the damper assembly rests against the inside wall of
unit.
3. Secure each damper assembly to unit with 6 screws
across top (3 screws provided) and bottom (3 screws
from Step 1) of damper.
4. With screws saved from Step 1, install brackets on
each side of damper assembly. See Fig. 22.
5. Remove tape from damper blades.
XII. STEP 12 — NON-FUSED DISCONNECT
The handle for the factory-installed non-fused disconnect is
shipped inside the unit to prevent the handle from being
damaged during shipping. Follow these steps to complete
installation of the handle.
WARNING: Be sure power is shut off to the unit
from the building power supply.
1. Open the control box access door.
2. Remove the small cover plate located on the unit corner post near the control s ection.
3. Remove the inner con trol box cover. The handle and
shaft are located in a plastic bag at the bottom of the
control box.
4. Insert the square shaft i nto the disconnect with the
pins vertical. On the 100-amp disconnect, the shaft is
keyed into the disconnect and can only be installed
one way (with the pins vertical).
5. Insert the handle through the corner post and onto
the shaft with the handle positioned so that “OFF” is
on top.
Fig. 22 — Bracket and Hood Positioning
6. Rotate the handle to the “ON” position to lock the
pins into the handle.
7. From the inside of the co rner post, a ttach the hand le
mounting screws to the handle. Slide the shaft fully
into the handle and tighten the set screw(s) on the
disconnect to lock the shaft. Tighten the screws that
attach the handle to the corner post.
8. Rotate the handle back to the “OFF” position.
9. Replace all panels and doors. Power can now be
turned back on to the unit.
XIII. STEP 13 — INSTALL ALL ACCESSORIES
After all of the factory- installed options have been a djusted,
install all field-instal led accessories. Refer to the accessory
installation ins tructions included with each acce ssory. Consult the Bryant Price Pages for accessory package numbers
for particular applications.
Fig. 21 — Power Exhaust or Barometric Relief Damper Mounting Details
—16—
PRE-START-UP
WARNING: Failure to observe the f ollowing warn-
ings could result in serious personal injury.
1. Follow recognized safety practices and wear
protective goggles when checking or the se rvicing refrigerant system.
2. Do not operate th e compressor or provide any
electric power to the unit unless the compressor
terminal cover is in place and secured.
3. Do not remove the compressor terminal cover
until all electrical sources are disconnected.
4. Relieve all pressure from the system before
touching or disturbing anything inside the
compressor terminal box if refrigerant leak is
suspected around the compressor terminals.
5. Never attempt to repair a sol dered connection
while the refrigerant system is under pressure.
6. Do not use torch to remove any component. The
system contains oil and refrigerant under pressure. To remove a component, wear protective
goggles and proceed as follows:
a. Shut off gas and then electrical power to
the unit. Install lockout tag.
b. Relieve all pressure from the system using
both high-pressure and low-pressure ports.
c. Cut the component connection tubing with
a tubing cutter, and remove the component
from the unit.
d. Carefully unsweat the remaining tubing
stubs when necessar y. Oil can igni te when
exposed to torch flame.
Proceed as follows to ins pect and prep are the unit f or initial
start-up:
1. Remove all access panels.
2. Read and follow instructions on all WARNING, CAUTION, and INFORMATION labels attached to, or
shipped with, the unit.
3. Make the following inspections:
a. Inspect for shipping and handling damages such
as broken lines, loose parts, or disconnected
wires, etc.
b. Inspect for oil at all refrigerant tubing connec-
tions and on unit base. Detecting oil generally
indicates a refrigerant leak. Leak-test all refrigerant tubing connections using an electronic leak
detector, halide torch, or liquid-soap solution.
c. Inspect all field-wiring and factory-wiring con-
nections. Be sure that connections are completed
and tight.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten the fins with a fin
comb.
4. Verify the following conditions:
a. Make sure that condenser fan blade is correctly
positioned in the fan orifice. See Condenser-Fan
Adjustment section on page 39 for more details.
b. Make sure that air filter(s) is in place.
c. Make sure that condensate drain trap is filled
with water to ensure proper drainage.
d. Make sure that all tools and miscellaneous loose
parts have been removed.
START-UP
Use the following information and Start-Up Checklist on
page CL-1 to check out unit PRIOR to start-up.
I. UNIT PREPARATION
Check that unit has been installed in accordance with these
installation instructions and all applicable codes.
II. COMPRESSOR MOUNTING
Compressors are internally spring mounted. Do not loosen or
remove compressor holddown bolts.
III. REFRIGERANT SERVICE PORTS
Each independent refrigerant system has a total of 3
Schrader-type service gage ports per circuit. One port is
located on the s uction l ine, one on the comp ressor discharge
line, and one on the liquid line. Be sure that caps on the
ports are tight.
IV. CRANKCASE HEATER(S)
Crankcase heaters are energized as long as there is power to
the unit and the compressor is not operating.
IMPORTANT: Unit power must be on for 24 hours prior to
start-up. Otherwise, damage to compressor may result.
V. COMPRESSOR PHASING
WARNING: Improper wiring will cause compres-
sor stoppage and may cause equipment damage. Correct wiring by switching leads as indicated below.
On 3-phase units, it i s important to be certain the compressors are rotating in the proper direction. To determine
whether or not compr essors are ro tating i n the pro per di rection, use a phase-rotation meter on the unit input power to
check for L1-L2-L3 or clockwise rotation. If the compressor is
rotating in the wrong direction, the suction pressure will not
drop and the discharge pressure will not rise.
NOTE: Indoor or outdoor fan rotation direction may not indicate proper input power phase sequence, as some 3-phase
units use single-phase fan motors. Check fan rotation where
applicable.
To correct the wrong compressor rotation dir ection, perform
the following procedure:
1. Turn off power to the unit and lock out the power.
2. Switch any two of the incoming unit power leads.
3. Turn on power to the unit.
4. Verify corrected compressor rotation a nd fan rota ti on
where applicable.
VI. INTERNAL WIRING
Check all electrical conne c tion s in unit c o ntrol b oxe s; tig hte n
as required.
VII. EVAPORATOR FAN
Fan belt and variable pulleys are factory-installed. See
Tables 5-23 for fan performance data. Be sure that fans
rotate in the proper direction. See Table 24 for air quantity
limits. See Table 25 for evaporator fan motor specifications.
See Table 26 for accessory or factory-installed options static
pressure. See Table 27 for fan rpm at various motor pulle y
settings. To alter fan performanc e, see Evaporator Fan Performance Adjustment section on page 39.
—17—
VIII. CONDENSER FANS AND MOTORS
Condenser fans and motors are factory set. Refer to
Condenser-Fan Adjustment section (page 39) as required.
IX. RETURN-AIR FILTERS
Check that correct filters are installed in filter tracks (see
Table 1). Do not operate unit without return-air filters.
NOTE: For units with 4-in. filter option, units are shipped
with standard 2-in. filters. To install 4-in. filters, the filter
spacers must be removed.
X. OUTDOOR-AIR INLET SCREENS
Outdoor-air inlet screens mu st be in place before op erating
unit.
XI. GAS HEAT
Verify gas pressures before turning on heat as follows:
1. Turn off field-supplied manual gas stop, located
external to unit.
2. Connect pressure gage to supply gas tap, located on
field-supplied manual shutoff valve (see Fig. 14).
3. Connect pressure gage to manifold pressure tap.
4. Turn on field-supplied manual gas stop. Provide a
call for heating stage 1.
5. After the unit has run for several minutes, verify
the supply gas pressure is between 5.5 in. wg and
13.0 in. wg. Provide a call for heating stage 2. Check
manifold pres sure after 5 minutes of sta ge 2 operation. Manifold pressure should be 3.00 in. wg. If
manifold pressure must be adjusted, refer to Gas
Valve Adjustment section.
Refer to this page for general Fan Performance Data notes.
NOTE: Maximum continuous bhp is:
Low Range: 8.63
High Range: 11.50
GENERAL NOTES FOR TABLES 5-22
1. Static pressure losses (i.e., EconoMi$er IV) from Table 26 must be
added to external static pressure before entering Fan Performance
table.
2. Interpolation is permissible. Do not extrapolate.
3. Fan performance is based on wet coils, clean filters, and casing
losses. See Table 26 on page 30.
4. Extensive motor and drive testing on these units ensures that the
full horsepower and watts range of the motor can be utilized with
confidence. Using the fan motors up to the watts or bhp rating
shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected.
5. Use of a field-supplied motor may affect wire size. Contact the
Bryant representative for details.
Low Range Vertical647667687707727747767786806826846866886
High Range Vertical897917937958978998 10181038 1058 10791099 11191139
Low Range Horizontal8969249519791006 1034 10621089 11171144 1172 11991227
High Range Horizontal1113 11381163 11881213 1238 12641289 13141339 1364 13891414
Low Range Vertical8108328548768979199419639851007 1028 10501072
High Range Vertical873893912932951971991 10101030 10491069 1088 1108
Low Range Horizontal863886909933956979 10021025 1048 10721095 11181141
High Range Horizontal1042 10621083 11031123 1143 11641184 12041224 1245 12651285
Low Range Vertical949970992 10131035 1056 10781099 11201142 1163 11851206
High Range Vertical941961980 10001019 10391059 1078 10981117 11371156 1176
Low Range Horizontal1113 11381163 1188 12131238 12641289 1314 13391364 1389 1414
High Range Horizontal1096 11161137 11571177 1197 12181238 12581278 1299 13191339
Low Range Vertical949970992 10131035 1056 10781099 11201142 1163 11851206
High Range Vertical941961980 10001019 10391059 1078 10981117 11371156 1176
Low Range Horizontal1113 11381163 1188 12131238 12641289 1314 13391364 1389 1414
High Range Horizontal1096 11161137 11571177 1197 12181238 12581278 1299 13191339
Low Range Vertical941961980 10001019 1039 10591078 10981117 1137 11561176
High Range Vertical1014 10381061 1085 11081132 11561179 1203 12261250 12731297
Low Range Horizontal941961980 10001019 10391059 1078 10981117 11371156 1176
High Range Horizontal1014 10381061 10851108 1132 11561179 12031226 1250 12731297
DRIVE
1
/
0
2
XII. OPTIONAL ECONOMI$ER IV
See Fig. 23 for EconoMi$er IV component locations. The
optional EconoMi$er I V comes from the factory full y wired
and assembled. No field wiring or assembly is required for
standard outdoor dry bulb changeover o peration. Field wiring of accessory sensors is required fo r different operat ional
modes.
A. EconoMi$er IV Standard Sensors
Outdoor Air Temperature (OAT) Sensor
The outdoor air temperature sensor (HH57AC074) is a 10 to
20 mA device used to measure the outdoor-air te mperature.
The outdoor-air temperature is used to determine when the
EconoMi$er IV can be used for free cooling. The sensor is
factory-installed on the EconoMi$er IV in the outdoor airstream. See Fig. 23. The operating range of temperature
measurement is 40 to 100 F.
Supply-Air Temperature (SAT) Sensor
The supply-air temperature sensor is a 3 K thermistor
located at the outlet of the indoor fan. See Fig. 24. This sensor is factory ins talled. The operat ing range of temper ature
measurement is 0° to 158 F.
The temperature sensor is a short probe with blue wires
running to it.
Outdoor Air Lockout Sensor
The EconoMi$er IV i s equipped with an ambient tem pera-
ture lockout switch located in the outdoor airstream which is
used to lock out the compressors below a 42 F ambient
temperature.
MOTOR PULLEY TURNS OPEN
111/
2
221/
2
331/
2
441/
2
551/
B. EconoMi$er IV Controller Wiring and Operational Modes
Determine the EconoMi$er IV control mode before set up of the
control. Some modes of operation may require different sensors.
Refer to Table 28. The EconoMi$er IV is supplied from the
factory with a supply-air temperature sensor and an
outdoor air temperature sensor. This allows for operation of
the EconoMi$er IV with outdoor air dry bulb changeover
control. Additional accessories can be added to a llow for different types of changeover control and operation of the
EconoMi$er IV and unit.
Outdoor Dry Bulb Changeover
The standard controller is shippe d from the factory config-
ured for outdoor dry bulb changeover control. The outdoor
air and supply-air temperature sensors are included as
standard. For this control mode, the outdoor temperatur e is
compared to an adjustable set point selected on the control.
If the outdoor-air temperature is above the set point, the
EconoMi$er IV 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 provid e fr ee co o lin g using outdoor air. When in this
mode, the LED next to the free cooling set point pot entiometer will be on. The changeover tempera ture set poi nt is controlled by the free cooling set poi nt potentiom eter located on
the control. The scale on the potentiometer is A, B, C, and D.
See Fig. 25 for the corresponding temperature changeover
values.
6
2
—30—
DAMPER
ASSEMBLY
WIRE
HARNESS
DAMPER
ACTUATOR
PL7
OUTDOOR AIR
TEMPERATURE
ECONOMIZER
BLOCK OFF
SENSOR
PL7
INDOOR AIR
ENTHALPY
SENSOR
OUTSIDE AIR
ENTHALPY
Fig. 23 — EconoMi$er IV Component Locations (Exploded View)
SAT LOCATION
Fig. 24 — Supply-Air Temperature Sensor Location
SENSOR
WIRE TIES
19
LED ON
18
17
16
15
mA
14
13
12
11
10
9
40
45
LED OFF
50
D
LED ON
C
LED OFF
60
55
65
DEGREES FAHRENHEIT
70
LED ON
LED OFF
75
B
LED ON
A
LED OFF
90
85
80
95
Fig. 25 — Outdoor-Air Temperature Changeover
Set Points
100
Table 28 — EconoMi$er IV Sensor Usage
APPLICATION
ECONOMI$ER IV WITH OUTDOOR AIR
DRY BULB SENSOR
Accessories RequiredAccessories Required
Outdoor Air Dry BulbNone. The outdoor air dry bulb sensor is factory installed.CRTEMPSN002A00*
Single EnthalpyHH57AC078None. The single enthalpy sensor is factory installed.
Differential Enthalpy
for DCV Control using a
CO
2
Wall-Mounted CO
for DCV Control using a
CO
2
Duct-Mounted CO
*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on many different base units. As such, these kits may contain parts that will not be needed
for installation.
†CGCDXSEN004A00 is an accessory CO
**CGCDXASP001A00 is an accessory aspirator box required for duct-mounted applications.
Sensor
2
Sensor
2
sensor.
2
HH57AC078
and
CRENTDIF004A00*
CGCDXSEN004A00CGCDXSEN004A00
CGCDXSEN004A00†
CGCDXASP001A00**
and
ECONOMI$ER IV WITH SINGLE
ENTHALPY SENSOR
CRENTDIF004A00*
CGCDXSEN004A00†
CGCDXASP001A00**
and
—31—
Differential Dry Bulb Control
For differential dry bulb control the standard outdoor dry
bulb sensor is used in conjunction with an additional accessory dry bulb sensor (part number CRTEMPSN002A00). The
accessory sensor mu st be mounted in th e return airstream.
Wiring is provided in the EconoMi$er IV wiring harness. See
Fig. 26.
In this mode of operation, the outdoor-air temperature is
compared to the return-air temperature and the l ower temperature airstream is used for cooling. When using this mode
of changeover control, turn the enthalpy set point potentiometer fully clockwise to the D setting.
ber HH57AC078) is required. Replace the standard outdoor
dry bulb temperature sensor with the accessory enthalpy
sensor in the same mounting location. When the outdoor air
enthalpy rises above the outdoor enthalpy changeover set
point, the outdoor-air damper moves to its minimum position. The outdoor enthalpy changeover set point is set with
the outdoor enthalpy set point potentiometer on the
EconoMi$er IV contro ller. The set points are A, B, C, and D.
See Fig. 27. The fact ory-in stal led 620 -ohm j umper must b e in
place across termina ls S
and + on the EconoMi$er IV con-
R
troller. See Fig. 26.
Differential Enthalpy Control
For differential enthalpy control, the EconoMi$er IV control-
ler uses two enthalpy sensors (HH57AC078 and
CRENTDIF004A00), one in the outside air and one in the
return air duct. The EconoMi$er IV controller compares the
outdoor air enthalpy to the return air enthalpy to determine
EconoMi$er IV use. The con tro ll er selects the low e r en thalpy
air (return or outdoor) for cooling. For example, when the
outdoor air has a lower enthalpy than the return air, the
EconoMi$er IV opens to b r ing in outdoor air for free cooling.
Replace the standard outside air dry bulb temperature
sensor with the accessory enthalpy sensor in the same
mounting location. Mount the return-air enthalpy sensor in
the return-air duct. Wiring is provid ed in the EconoMi$er IV
wiring harness. See Fig. 26. The outdoor enthalpy
changeover set point is set with the outdoor enthalpy set
point potentiometer on the EconoMi$er I V controller. When
using this mode of changeover control, turn the enthalpy set
point potentiometer fully clockwise to the D setting. See
Fig. 28.
Indoor Air Quality (IAQ) Sensor Input
The IAQ input can be used for demand control ventilation
control based on the level of CO
measured in the sp ace or
2
return-air duct.
Mount the optional IAQ sensor according to manufacturer
specificatio ns . Th e IA Q sen sor s hou ld be w ired to the A Q and
AQ1 terminals of the controller. Adjust the DCV (demand
controlled ventilation) potentiometers to correspond to the
DCV voltage output of the i ndoor air quality sensor at the
user-determined set point. See Fig. 29.
If a separate field-supplied transformer is used to power the
IAQ sensor, the sensor must not be grounded or the
EconoMi$er IV control board will be damaged.
Exhaust Set Point Adjustment
The exhaust set point will determine when the exhaust fan
runs based on d am p er po sit i on ( if accessory power exhaust is
installed). The set point is modified with the Exhaust Fan
Set Point (EXH SET) potentiometer. See Fig. 28. The set
point represents the damper position above which the
exhaust fans will be turned on. When there is a call
for exhaust, the EconoMi$er IV controller provides a
45 ± 15 second delay before exhaust fan activation to allow
the dampers to open. This del ay allows the damper to reach
the appropriate position to avoid unnecessary fan overload.
LEGEND
IA — Indoor Air
IAQ — Indoor Air Quality
OA — Outdoor Air
OAS — Outdoor-Air Temperature Sensor
PL — Plug
RAS— Return-Air Temperature Sensor
SAT — Supply-Air Temperature Sensor
Fig. 26 — EconoMi$er IV Wiring
—32—
CONTROL
CURVE
4
1
2
1
A
B
C
D
8
1
6
1
CONTROL POINT
APPROX. °F (°C)
AT 50% RH
73 (23)
70 (21)
67 (19)
63 (17)
P
L
HA
26
NT
E
4
2
2
2
0
2
40
(4)
35
(2)
Y
—
85
(29)90(32)95(35)
46
4
4
42
40
IR
8
3
Y A
6
DR
3
D
N
U
4
3
PO
R
32
E
P
TU
30
B
28
60
(16)
55
(13)
B
50
C
(10)
45
D
(7)
70
(21)
0
0
1
65
(18)
A
80
(27)
75
(24)
0
9
80
70
60
50
0
4
TIVE HUM
RELA
0
3
100
(38)
IDITY
20
(%
105
110
(41)
(43)
)
0
1
B
C
D
35
40
45
50
55
60
65
70
75
(2)
(4)
(7)
(10)
(13)
(16)
(18)
(21)
(24)
80
(27)
APPROXIMATE DRY BULB TEMPERATURE— °F (°C)
Fig. 27 — Enthalpy Changeover Set Points
6000
5000
4000
3000
2000
1000
RANGE CONFIGURATION (ppm)
A
HIGH LIMIT
85
(29)90(32)95(35)
CO SENSOR MAX RANGE SETTING
105
(41)
110
(43)
100
(38)
2
CURVE
0
2345678
DAMPER VOLTAGE FOR MAX VENTILATION RATE
800 ppm
900 ppm
1000 ppm
1100 ppm
Fig. 28 — EconoMi$er IV Controller Potentiometer and
LED Locations
—33—
Fig. 29 — CO
Sensor Maximum Range Setting
2
Minimum Position Control
There is a minimum damper p osition potent iometer on the
EconoMi$er IV c o nt r oll er. See Fig. 28. The minimum dam per
position maintains the minimum airflow into the building
during the occupied period.
When using demand ventilation, the minimum damper
position represents the minimum ventilation position for
VOC (volatile organi c compounds ) ventilati on requirem ents.
The maximum demand ventilation position is used for fully
occupied ventilation.
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 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:
OA
(T
x
O
T
= Outdoor-Air Temperature
O
)+ (TR x
100100
RA
) = T
M
OA = Percent of Outdoor Air
= Return-Air Temperature
T
R
RA = Percent of Return Air
TM = Mixed-Air Temperature
As an example, if local codes require 10% outdoor air
during occupied conditions, outdoor-air temperature
is 60 F, and return-air temperature is 75 F.
(60 x .10) + (75 x .90) = 73.5 F
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 accor din g to Fig. 26 and that t he mi nimu m
position potentiometer is turned fully clockwise.
4. Connect 24 vac across terminals TR and TR1.
5. Carefully adjust th e minim um positi on potent iomet er
until the measured mixed-air temperature matches
the calculated va lue.
6. Reconnect the supply-air sensor to terminals T and
T1.
Remote control of the EconoMi$er IV damper is desirable
when requiring additional temporary ventilation. If a
field-supplied remote potentiometer (Honeywell part number S963B1128) is wired to the E co no Mi$er IV controlle r, the
minimum position of the damper can be controlled from a
remote location.
To control the minimum damper position remotely, remove
the factory-insta lled jumper on the P and P1 terminals on
the EconoMi$er IV controller. Wire the field-supplied potentiometer to the P and P1 termina ls on the EconoMi$er IV
controller. See Fig. 26.
Damper Movement
Damper movement from full open to full closed (or vice
versa) takes up to 21/2 minutes.
Thermostats
The EconoMi$er IV control works with conventional thermo-
stats that have a Y1 (cool stage 1), Y2 (cool stage 2), W1
(heat stage 1), W2 (heat stage 2), and G (fan). The
EconoMi$er IV control do es not support space temperature
sensors like the T55 or T56. Connections are made at the
thermostat terminal connection board located in the main
control box.
Occupancy Control
The factory default configuration for the Econo Mi$er IV con -
trol is occupied mode. Occupied status is provided by the
black jumper from terminal TR to terminal N. When unoccupied mode is desired, install a field-supplied timeclock function in place of th e jumper between TR an d N. See Fig. 26.
When the timeclock contacts are closed, the EconoMi$er I V
control will be in occupied mode. When the timeclock contacts are open (removin g the 24-v signal from terminal N),
the EconoMi$er IV will be in unoccupied mode.
Demand Control V enti lation
When using the EconoMi$er IV for demand control ventila-
tion, there are some equipment 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 conditio ns. The maximum
damper position must be calculated to provide the desired
fresh air.
Typically the maximum ventilation rate will be ab out 5 to
10% more than the typical cfm required per person, using
normal outside air design criteria.
A proportional anticipatory strategy should be taken with
the following conditions: a zone with a large area, varied
occupancy, and equipment that cannot exceed the requ ired
ventilation rate at design con dition s. Exceeding th e requ ired
ventilation rate means the equipment can co ndition air a t a
maximum ventilation rate that is gre ater than the requ ired
ventilation rate for maximum occupancy. A proportionalanticipatory strategy will cause the fresh air supplied to
increase as the room CO
level increases even though the
2
CO2 set point has not been reached. By the time the CO
level reaches the set point, the damper will be at maximum
ventilation and should maintain the set point.
In order to have the CO
sensor control the economizer
2
damper in this manner, first determine the damper voltage
output for minimum or base ventilatio n. Base ven tilation 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 degree difference in outside and return-air
temperatures.
OA
(TO x
100100
)+ (TR x
RA
) = T
M
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.
2
—34—
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 t o the ac tuat o r pro vide s a ba se ve ntil at io n
rate of 5% and an output of 6.7 volts provides the maximum
ventilation rate of 20% (or bas e plu s 15 cfm pe r pers on). Use
Fig. 29 to determine the maximum setting of the CO
sensor.
2
For example, a 1100 ppm set point relates to a 15 cfm per
person design. Use the 1100 ppm curve on Fig. 29 to find the
point when the CO
sensor output will be 6.7 volts. Line up
2
the point on the graph with the left side of the chart to determine that the range configuration for the CO
sensor sho uld
2
be 1800 ppm. The EconoMi$er IV controller will output the
6.7 volts fro m the CO
sensor to the actuator when the CO
2
concentration in the spac e is a t 1100 ppm . The D CV set point
may be left at 2 volts since the CO
sensor voltage wi ll be
2
ignored by the Econ oMi$er IV co ntroller u ntil it rises above
the 3.6 volt setting of the minimum position potentiometer.
Once the fully occupied damper position has been determined, set the maximu m da mpe r de ma nd con t ro l ve nt il atio n
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.
CO
Sensor Configurati on
2
The CO2 sensor has preset standard voltage settings that
can be selected anytime afte r the sensor is powere d up. See
Table 29 .
Use setting 1 or 2 f or Bryant equip ment. See Table 29.
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 29.
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 any-
2
time after the sensor is ener gized. Follow the steps below to
change the non-standard 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 (American Society of Heating,
Refrigeration, and Air Conditioning Engineers) indicates
2
that the largest humidity load on any zone is the fresh air
introduced. For some applications, an ener gy recovery unit
can be added to reduce the moisture con tent of the fre sh air
being brought int o the building when the enth alpy 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 l evel, an energ y recovery
and/or a dehumidification option should be considered.
XII. OPERATING SEQUENCE
A. Cooling, Units Without Economizer
When the thermostat calls for one stage of cooling, Y1 and G
are energized. Th e indoor-fan contactor (IFC) and com pressor contactor(s) (C.A1 and C.B1 on three-compressor units or
C.A1 only on two-compressor uni ts), and out door-fan conta ctors (OFC1 and OFC2 when outdoor temperature is above
FCS [fan cycling switch] setting) are energized and the
indoor-fan motor, compressor(s) (A1 and B1 on threecompressor units or A1 only on two-c ompressor units), and
outdoor fans controlled by OFC1 are started. If the outdoor
temperature is above the setting of the low temperature
switch, the outd oo r fa ns co nt r ol le d by O FC 2 ar e al so sta rte d.
If more cooling is required, the thermostat will call for a second stage of cooling, energizing Y2. This will allow relay CR1
to energize, which in turn ene rgize s the com presso r contact or
(C.C1 on three-compressor units or C.B1 on two-compressor
units). The second stage compressor (C1 on three-compressor
units or B1 on two-compressor units) is then started.
Tab l e 2 9 — CO
SETTINGEQUIPMENTOUTPUT
1
Interface w/Standard
2ProportionalAny
Building Control System
3ExponentialAny
4
5Proportional20
Economizer
6Exponential15
7Exponential20
8Health & SafetyProportional—
Parking/Air Intakes/
9
Loading Docks
LEGEND
ppm — Parts Per Million
ProportionalAny
Proportional15
Proportional—
Sensor Standard Settings
2
VENTILATION
RATE
(cfm/Person)
ANALOG
OUTPUT
0-10V
4-20 mA
2-10V
7-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
—35—
CO
CONTROL RANGE
2
(ppm)
0-2000100050
0-2000100050
0-2000110050
0-1100110050
0- 90090050
0-1100110050
0- 90090050
0-99995000500
0-200070050
OPTIONAL
RELAY SETPOINT
(ppm)
RELAY
HYSTERESIS
(ppm)
B. Heating, Units Without Economizer
NOTE: The 581A210-300 units have 2 stages of electric heat.
When the thermostat calls for heating, power is sent to W on
the IGC (integrated gas unit controller) board. An LED
(light-emitting diode) on the IGC board will be on during
normal operation. A check is ma de to en sure that t he rol lou t
switch and limit switch are closed and the induced-draft
motor is running. The induced-draft motor is then energized,
and when speed is pr oven with the hall eff ect sensor on the
motor, the ignition activation period begins. The burners will
ignite within 5 seconds.
If the burners do not light, there is a 22-second delay before
another 5-s econd attempt. If the burners still do not light,
this sequence is repeat ed for 15 minutes. After the 15 minutes have elapsed, if the burners still have not lit, heating
is locked out. To reset the control, break 24-v power to the
thermostat.
When ignition occurs the IGC board will continue to monitor
the condition of the ro ll ou t and limit switches, the hall effect
sensor, as well as the flame sensor. If the unit is controlled
through a room thermostat set for fan auto., 45 seconds after
ignition occurs, the indoor-fan motor wil l be energized (and
the outdoor-air dampers will open to their minimum position). If for some reason the overtemperature limit opens
prior to the start of the indoor fan blower, on the next
attempt, the 45-second delay will be sho rtened to 5 seconds
less than the time from initiation of heat to when t he limit
tripped. Gas will not be interrupted to the burners and heating will contin ue. Once modified, the f an on delay will not
change back to 45 seconds unless power is reset to the
control.
When additional heat is required, W2 closes and initiates
power to the second stage of the main gas valve. When the
thermostat is satisfied, W1 and W2 open and the gas valve
closes, interrupting the flow of gas to the main burner s. If
the call for W1 lasted less than 1 minute, the heating cycle
will not terminate until 1 minute after W1 became active. If
the unit is controlled through a ro om thermostat set for fan
auto., the indoor-fan motor will continue to operate for an
additional 45 se conds then stop (and the o utdoor-air dampers will close). If th e overtemperature limi t opens after the
indoor motor is stopped within 10 minutes of W1 becoming
inactive, on the next cycle the time will be extended by
15 seconds. The maximum delay is 3 minutes. Once modified, the fan off delay will not change back to 45 seconds
unless power is reset to the control.
A LED indicator is provided on the IGC to monitor operation. The IGC is located by removing the side panel and
viewing the IGC through the view port located in the cont rol
box access panel. During normal operation, the LED is continuously on. For information on troubleshooting refer to
page 47.
C. Cooling, Units With EconoMi$er IV
When free cooling is not available, the compressors will be
controlled by the zone thermostat. When free cooling is available, the out do or-air da mpe r i s m o du la te d by the EconoMi $ er
IV control to provide a 50 to 55 F supply-air temperature into
the zone. As the supply-ai r temperatur e fluctuate s above 55 or
below 50 F, the dampers will be modulated (open or close) to
bring the supply-air temperature back within the set points.
Integrated EconoMi$er IV operation on single-stage units
requires a 2-stage thermostat (Y1 and Y2).
For EconoMi$er IV operation, there must be a thermostat
call for the fan (G). This will move the damper to its minimum position during the occupied mode.
Above 50 F supply-air temperature, the dampers will modulate from 100% open to the minimum open position. From
50 F to 45 F supply-air temperature, the dampers will maintain at the minimum open position. Below 45 F the dampers
will be completely shut. As the supply-air temperature rises,
the dampers will com e back op e n to the m ini mum open posi tion once the supply-air temperature rises to 48 F.
If optional power 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
2
EconoMi$er IV control, a demand controlled ventilation
strategy will begin to opera te. As the CO
increases abo ve the CO
set point, the minimum position of
2
level in the zone
2
the damper will be increased proportionally. As the CO2 level
decreases because of the increase in fresh air, the outdoor-air
damper will be propo rtionally closed. Damper position will
follow the higher demand condition from DCV mode or free
cooling mode.
Damper movement from full closed to full open (or vice
versa) will take between 1
1
/2 and 21/2 minutes.
If free cooling can be used as determined from the appropriate changeover command (switch, dr y bulb, enthalpy curve,
differential dry bulb, or differential enthalpy), a call for cooling (Y1 closes at the thermostat) will cause the control to
modulate the dampers open to maintain the supply a ir temperature set point at 50 to 55 F.
As the supply air temperature drops belo w the set point range
of 50 to 55 F, the control will modulate the outdoor-air dampers closed to maintain the proper supply-air temperature.
D. Heating, Units With EconoMi$er IV
When the room temperature calls for heat, the heating controls are energized as described in the Heating, Units Without Economizer section. The IFM is energized and the
EconoMi$er IV damper modulates to the minimum position.
When the thermostat is satisfied and W1 and W2 are deenergized, the IFM continues to run, and the economizer damper
modulates to the minimum position.
SERVICE
WARNING: Before performing service or mainte-
nance operations on unit, turn off main power switch
to unit. Electrical shock could cause personal injury.
I. CLEANING
Inspect unit i nterior at beginn ing of each heating and cooling season an d a s oper ating conditi o ns re q ui re. Re mo ve uni t
top panel and/or side panels for access to unit interior.
A. Coil Maintenance and Cleaning Recommendation
Routine cleaning of coil surfaces is essential to maintain
proper operation of the unit. Elimination of contamination
and removal of harmful residues will greatly increase the life
of the coil and ext end th e li fe of the unit. Th e follo wing maintenance and cleaning pr ocedur es are recom mended a s part of
the routine maintenance activities to extend the life of the
coil.
—36—
Remove Surface Loaded Fibers
Surface loaded fibers or dirt should be removed with a vac-
uum cleaner. If a vacuum cleaner is not available, a soft nonmetallic bristle brush may be used. In either case, the tool
should be applied in the direction of the fins. Coil surfaces
can be easily damaged (fin edges can be easily bent over and
damage to the coating of a protected coil) if the tool is applied
across the fins.
NOTE: Use of a water stream, such as a garden hose, against
a surface loaded coil will drive the fibers and dirt into the
coil. This will make cleanin g efforts more difficult. Surface
loaded fibers must be co mpl etely remo ved p rior to us ing lo w
velocity clean water rinse.
Periodic Clean Water Rinse
A periodic clean water rinse i s very beneficial for coils th at
are applied in coastal or industrial environments. However,
it is very important t hat the water rinse is made with ver y
low velocity water stream to avoid damaging the fin edges.
Monthly cleaning as described below is recommended.
Routine Cleaning of Coil Surfaces
Monthly cleaning with Totaline® environmentally sound coil
cleaner is essential to extend the life of coils. This cleaner is
available from Replacement parts division as part number
P902-0301 for a one gallon container, and part number
P902-0305 for a 5 gallon container. It is recommended that all
coils, including standard aluminum, pre-co ated, copper/coppe r
or E-coated coils be cleaned with the Totaline environmentally
sound coil cleaner as described below. Coil cleaning should be
part of the unit’s regularly scheduled maintenance pro cedures
to ensure long life of the coil. Failure to clean the coils may
result in reduced durability in the env iro nment.
Avoid the use of:
• Coil brighteners
• Acid cleaning prior to painting
• High pressure washers
• Poor quality water for clean ing
Totaline environmental ly sound coil cleaner is non-flammable,
hypoallergenic, nonbacterial, and a USDA accepted biodegradable agent that will not harm the coil or surrounding
components su ch as ele ctrica l wiring, pain ted metal surfa ces,
or insulation. Use of non-recommended coil cleaners is
strongly discouraged since coil and unit durability could be
affected.
• Wate r rinse with low velocity spray nozzle
CAUTION: Harsh chemicals, household bleach or
acid or basic cleaners should not be used to clean
outdoor or indoor coi ls of any kin d. These cle aners can
be very difficult to rinse out of the coil and can
accelerate corrosion at the fin/tube interface where
dissimilar materials are in contact. If there is dirt
below the surface of the coil, use the Totaline
environmentally sound coil cleaner as described
above.
CAUTION: High velocity water from a pressure
washer, garden hose, or compressed air should never
be used to clean a coil. The force of t he water or a ir jet
will bend the f in edges and increase airsi de pressure
drop. Reduced unit performance or nuisance unit
shutdown may occur.
1. Proper eye protection such as safety glasses is recommended during mixing and application.
2. Remove all surface loaded fibers and dirt with a vacuum cleaner as described above.
3. Thoroughly wet finned sur face s with clea n w ater and a
low velocity garden hose, being careful not to bend fins.
4. Mix Totaline environmentally sound coil cleaner in a
1
/2 gallon garden sprayer according to the instruc-
2
tions included with the cleaner. The optimum solution temperature is 100 F.
NOTE: Do NOT
USE water in excess of 130 F, as the enzy-
matic activity will be destroyed.
5. Thoroughly apply Totaline environmentally sound
coil cleaner solution to all coil surfaces including
finned area, tube sheets and coil headers.
6. Hold garden sprayer nozzle cl ose to finned area s and
apply cleaner with a vertical, up-and-down motion.
Avoid spraying in horizontal pattern to minimize
potential for fin damage.
7. Ensure cleaner thoroughly penetrates deep into
finned areas.
8. Interior and ext eri or fin ned area s must be th oro ughly
cleaned.
9. Finned surfaces should remain wet with cleaning
solution for 10 minutes.
10. Ensure surfaces are not allowed to dry before rinsing.
Reapplying cleaner as needed to ensure 10-minute
saturation is achieved.
11. Thoroughly ri nse all surfaces with low velocity clean
water us in g do wn wa rd r in si ng m ot io n of wa te r sp r ay
nozzle. Protect fins from damage from the spray
nozzle.
B. Condensate Drain
Check and clean ea ch y ear at the sta rt of th e co olin g se as on.
In winter, keep drains and traps dry. An access panel is
located above the condensate co nnection to allow easy clean
out of the condensate pan. The first time the panel is
removed, the insulation behind the access panel will need to
be cut away. Carefully cut the insulation with a knife or
blade on three sid es so th e in sul at io n c an be fo ld ed o ut of the
way during cleaning. Be careful not to damage components
behind the insulation while cutting. Once cleaning is completed, fold the insulation back into place and secure the
access panel in the original position.
C. Filters
Clean or rep lace at s tar t of e ach h eati ng an d co oling seas on,
or more often i f ope rat ing cond iti ons r equir e . Re fer to Table 1
for type and size.
D. Outdoor-Air Inlet Screens
Clean screens with steam or hot water and a mild detergent.
Do not use thro waway filters in p l ace of scr ee ns. See Table 1
for quantity and size.
E. Main Burner
At the beginning of each heating season, inspect for deterioration or blockag e due to cor rosion or ot her causes. Obs erve
the main burner f lames. Refer to Main Burners section on
page 41.
—37—
F. Flue Gas Passageways
The flue collector box and heat exchanger cells may be
inspected by removing heat section access panel (Fig. 4), flue
box cover, and main burner assembly (Fig. 30). Refer to Main
Burners section on pa ge 41 for burner remo val sequence. If
cleaning is required, cle an tube s with a wire brush.
Use caution with ceramic heat exchanger baffles. When
installing retaining clip, be sure the center leg of the clip
extends inward toward baffle. See Fig. 31.
G. Combustion-Air Blower
Clean periodically to assure proper airflow and heating efficiency. Inspect blower wheel every fal l and periodically du ring heating season. For the first heating season, inspect
blower wheel bi-monthly to determine proper cleaning
frequency.
To inspect blower wheel, remove heat section panel. Using
an inspection mirror and flashlight, look into the flue
exhaust duct to inspect the wheel. If cleaning is required,
remove motor and wheel assembly by removing the screws
holding the flue box cover to the flue box. See Fig. 30.
Remove the scre ws holding the inducer hous ing to the in let
plate. The wheel c an then be remo ved from the mo tor shaft
and cleaned with a detergent or solvent. Replace the wheel
onto the motor shaft in the c orrect position and reassemble
the flue cover onto the flue box.
II. LUBRICATION
A. Compressors
Each compressor is charged w ith the correct amount of oil at
the factory. Conventional white oil (Zerol 150T or Sontex
SA32) is used. White oil is compatible with 3GS oil, and 3GS
oil may be used if the addition of oil is required. See compressor nameplate for origi nal oi l ch arge. Oil re charge am oun t is
shown in Table 1. When a compressor is exchanged in the
field it is possible that a major portion of the oil from the
replaced compresso r may still be in the system. While this
will not affect the reliability of the replacement com pressor,
the extra oil will add rotor drag and increase power usage. T o
remove this excess oil, an access valve may be added to the
lower portion of the suction line at the inlet of the compressor. The compressor should then be run for 10 minutes, shut
down and the access valve opened until no oil flows. This
should be repeat ed twice to make sure the pro per oil level
has been achieved.
B. Fan Shaft Bearings
Lubricate bearings at least every 6 months with suitable
bearing grease. Typical lubricants are given below:
MANUFACTURERLUBRICANT
TexacoRegal AFB-2*
MobilMobilplex EP No. 1
SunocoPrestige 42
TexacoMultifak 2
*Preferred lubricant because it contains rust and oxidation inhibitors.
HEAT
EXCHANGER
SECTION
IGC BOARD
(HIDDEN)
MAIN BURNER
SECTION
LEGEND
IGC — Integrated Gas Controller
Fig. 30 — Typical Gas Heating Section
CERAMIC
BAFFLE
COMBUSTION
FAN HOUSING
INDUCED
DRAFT
MOTOR
MAIN GAS
VALV E
C. Condenser and Evaporator-Fan Motor Bearings
The condenser an d ev ap o rat or-fan moto rs hav e pe rma nen tl y
sealed bearings , so no fie ld lubric ati on is nec e ssa ry.
III. EVAPORATOR FAN SERVICE AND REPLACEMENT
The 581A units feature a slide-out fan deck for easy servicing of the indoor-fan motor, pulleys, belt, and bearings. To
service components in this section, perform the following
procedure:
1. Turn off unit power.
2. Open the fan section access panel.
3. Remove three no. 10 scre ws at front of slide-out fan
deck. Save screws. See Fig. 32.
4. Disconnect the electrical plugs and wires connected
to the slide-out fan deck (evaporator fan plug, supply
air thermistor, and fan status switch if installed).
Wires may be damaged if not disconnected.
5. Fan deck can now be slid out to access serviceable
components.
CAUTION: DO NOT SLIDE FAN DECK OUT
PAST THE STOP BRACKET. If further access is
required, the fan deck must be supported. M ake sure
plugs and wiring are not pinched between fan housing
and unit center post. Damage to unit may result.
CLIP
NOTE: One baffle and clip will be in each upper tube of the heat
exchanger.
Fig. 31 — Removing Heat Exchanger Ceramic Baffles
and Clips
6. To replace fan deck to operating position, slide fan
deck back into the unit. Secure with the three no. 10
screws removed in Step 3.
7. Re-attach electrical plugs and wires.
8. Close fan section access door.
9. Restore power to unit.
—38—
IV. EVAPORATOR FAN PERFORMANCE ADJUSTMENT
(Fig. 32 and 33)
Fan motor pulleys are factory set for speed shown in Table 1.
To change fan speeds:
1. Shut off unit power supply.
2. Loosen nuts on the 4 carriage bolts in th e mounting
base. Using adjust ing bolt s and plate , slide mo tor and
remove belt.
3. Loosen movable-pulley flange setscrew (see Fig. 33).
4. Screw movable flange toward fixed flange to increase
speed and away from fixed flange to decrease speed.
Increasing fan speed incr eases lo ad on motor. Do not
exceed maximum speed specified in Table 1.
See Table 24 for air quantity limits.
5. Set movable flange at nearest keyway of pulley hub
and tighten setscrew. (See Table 1 for speed change
for each full turn of pulley flange.)
6. Replace and tighten belts (see Belt Tension Adjustment section below).
7. Restore power to unit.
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from
mounting plate.
V. BELT TENSION ADJUSTMENT
To adjust belt tension:
1. Turn off unit power.
2. Slide out fan deck to servic e positio n as shown in Evaporator Fan Service and Replacement s ect io n ab ov e.
3. Loosen fan motor bolts.
4. Move motor mounting plate to adjust to proper belt
tension. See Table 30. Motor adjuster bolts may be
used to tighten belts. See Fig. 32.
5. Check for proper belt alignment. Adjust if necessary.
6. Tighten motor mounting plate bolts to lock motor in
proper position.
7. Return fan deck back into operating position.
8. Restore power to unit.
Table 30 — Belt Tension Adjustment
VI. CONDENSER-FAN ADJUSTMENT (Fig. 34)
1. Shut off unit power supply.
2. Remove condenser-fan assembly (grille, motor, motor
cover, and fan) and loosen fan hub setscrews.
3. Adjust fan height as shown in Fig. 34.
4. Tighten setscrews and replace condenser-fan assembly.
Dampers have a spring return. In event of power failure,
dampers will return to fully closed position until power is
restored. Do not manually operate damper motor.
VIII. REFRIGERANT CHARGE
Amount of refrigerant charge is listed on unit nameplate and
in Table 1. Refer to GTAC II; Module 5; Charging, Recovery,
Recycling, and Reclamation section for charging methods
and procedures. Unit panels must be in place when unit is
operating during charging procedure.
NOTE: Do not use recycled refrigerant as it may contain
contaminants.
A. No Charge
Use standard evacuating techniques. After evacuating system, weigh in the specifi ed amount of refrigerant (refer to
Table 1).
B. Low Charge Cooling
Using cooling charging chart (see Fig. 35-37), add or remove
refrigerant until conditions of the chart are met. An accurate
pressure gage and temperature-sensing device is required.
Charging is accomplished by ensuring the proper amount of
liquid subcooling. Measure liquid line pressure at the liquid
line service valve using pressure gage. Connect temperature
sensing device to the liquid line near the liquid line service
valve and insulate it so that outdoor ambient temperature
does not affect reading.
C. To Use the Cooling Charging Chart
Use the above tempe rature and pre ssure readings, and find
the intersection point on the cooling char ging chart. If intersection point on chart is above line, add refrigerant. If intersection point on chart is below line, carefully recover some of
the charge. Recheck suction pressure as charge is adjusted.
NOTE: Indoor-air cfm must be within normal operating
range of unit. All outdoor fans must be operating.
The TXV (thermostatic expansion valve) is set to maintain
between 10 and 15 degrees of superheat at the compressors. The valves are factory set and should not require
re-adjustment.
IX. GAS VALVE ADJUSTMENT
A. Natural Gas
The gas valve opens and closes in response to the thermostat
or limit control.
When power is supplied to valve terminals W2 (High Fire)
and C1, the main valve opens to its preset position.
The regular factory setting is stamped on the valve body. The
setting is 3.00 in. wg for vertical supply/discharge units. The
setting is 2.95 in. wg for horizontal supply/discharge units.
To adjust regulator:
1. Set unit at setting for no call for heat.
2. Turn main gas valve to OFF position.
3. Remove
1
/8-in. pipe plug from manifold or gas valve
pressure tap connection. Install a suitable pressuremeasuring dev ice.
4. Set main gas valve to ON position.
5. Set thermostat at setting to call for heat.
6. Remove screw cap covering regulator adjustment
screw (see Fig. 38).
7. Turn adjustment screw clockwise to increase pressure or counterclockwise to decrease pressure.
LEGEND
TXV — Thermostatic Expansion Valve
Fig. 35 — Cooling Charging Chart — 581A210 Units
LEGEND
TXV — Thermostatic Expansion Valve
Fig. 36 — Cooling Charging Chart — 581A240 Units
LEGEND
TXV — Thermostatic Expansion Valve
Fig. 37 — Cooling Charging Chart — 581A300 Units
—40—
8. Once desired pressure is established, set unit setting
for no call for heat, turn off main gas valve, remove
pressure-measuring device, and replace
1
/8-in. pipe
plug and screw cap.
X. MAIN BURNERS
For most applications, main burners are factory set and
should require no adjustment.
For applications at altitudes above 2000 ft, refer to
Tables 31 and 32 for altitude compensation.
A. Main Burner Removal
1. Shut off (field-supplied) manual main gas valve.
2. Shut off power to unit.
3. Remove gas section access panel.
4. Disconnect gas piping from gas valve inlet.
5. Remove wires from gas valve.
6. Remove wires from rollout switch.
7. Remove sensor wire and ignitor cable from IGC
board.
8. Remove 2 screws securing manifold bracket to
basepan.
9. Remove 2 screws that hold the burner assembly to
vestibule plate.
10. Lift burner/manifold assembly out of unit.
B. Cleaning and Adjustment
1. Remove burner rack from unit as described in Main
Burner Removal section above.
2. Inspect burners, and if dirty, remove burners from
rack.
3. Using a soft brush, clean burners and crossover port
as required.
Replace whenever refrigerant system is exposed to
atmosphere.
XII. PROTECTIVE DEVICES
A. Compressor Protection
Overcurrent
Each compressor has intern al line break motor protection.
Overtemperature
Each compressor has an internal protector to protect it
against excessively high discharge gas temperatures.
Compressor Lockout
If any of the safeties (high-pressure, low-pressure, freeze
protection thermostat, compressor internal thermostat) trip,
or if there is loss of power to the compressors, the cooling
lockout (CLO) will lock the compressors of f. To reset, manually move the thermostat setting.
INLET PRESSURE TAP
(PLUGGED)
1/8 - 27 N.P.T. THDS.
ON
W-1
OFF
RECEPTACLE TERMINAL
REGULATOR
ADJUSTMENT SCREW
(REMOVE COVER)
D-1
D-2
C1
C2
PILOT
ADJ.
W-2
OUTLET PRESSURE
TAP (PLUGGED)
1/8-27 N.P.T. THDS.
RECEPTACLE AND
TAB COMBINATION
TERMINAL
PILOT CONNECTION
FOR 1/4” O.D. TUBING
(PLUGGED)
Fig. 38 — Gas Valve
—41—
B. High-Pressure and Low-Pressure Switches
If either switch trips, or if the compressor overtemperature
switch activates, that refrigerant circuit will be automatically locked out by the CLO. To reset, manually move the
thermostat setting.
C. Freeze Protection Thermostat (FPT)
An FPT is located on the top and bottom of the evaporator
coil. They detect frost build-up and turn off the compressor,
allowing the coil to clear. Once the frost has melted, the
compressor can be reenergize d by resetting the compressor
lockout.
D. Evaporator Fan Motor Protection
A manual reset, calibrated trip, magnetic circuit breaker
protects against ov ercurrent. Do not bypass connections or
increase the size of the breaker to correct trouble. Determine
the cause and correct it before resetting the breaker.
E. Condenser-Fan Motor Protection
Each condenser-fan motor is internally protected against
overtemperature.
Fuses are also located in the control box and feed powe r to
the condenser fan moto rs. Always replace blown fuses with
the correct size fuse as indicated on the unit fuse label.
XIII. RELIEF DEVICES
All units have relief devices to protect agains t damage from
excessive pressures (i.e., fire). These devices protect the high
and low side.
XIV. CONTROL CIRCUIT, 24-V
Each control circuit is protected against overcurrent by a
3.2 amp circuit breaker. Breaker can be reset. If it trips,
determine cause o f trouble before resetting. See Fig. 40- 42
for wiring.
XV. REPLACEMENT PARTS
A complete list of repl acement parts may be obtained from
any Bryant distributor upon request.
XVI. DIAGNOSTIC LEDs
The IGC control board has a LED for diagnostic pur poses.
The IGC error codes are shown in Table 33.
Table 33 — IGC LED Indications
Normal OperationOn
Hardware FailureOff
Fan On/Off Delay Modified1 Flash
Limit Switch Fault2 Flashes
Flame Sense Fault3 Flashes
Five Consecutive Limit Switch Faults4 Flashes
Ignition Lockout Fault5 Flashes
Inducer Switch Fault6 Flashes
Rollout Switch Fault7 Flashes
Internal Control Fault8 Flashes
Software Lockout9 Flashes
LEGEND
IGC — Integrated Gas Unit Controller
LED — Light-Emitting Diode
NOTES:
1. There is a 3-second pause between error code displays.
2. If more than one error code exists, all applicable error codes will be
displayed in numerical sequence.
3. Error codes on the IGC will be lost if power to the unit is
interrupted.
ERROR CODELED INDICATION
SEE DETAIL “C”
Fig. 39 — Spark Gap Adjustment
—42—
LEGEND
Fig. 41 — Power Schematic and Fig. 42 — Component Arrangement
Fig. 40 — Low Voltage Control Schematic
_ _ .A — Circuit A
AHA— Adjustable Heat Anticipator
AL— Ambient Limit
AUX— Auxiliary Contact
_ _ .B — Circuit B
_ _ .C — Circuit C
C—Compressor, Contactor
CAP— Capacitor
CB— Circuit Breaker
CC— Compressor Contactor
CCH— Crankcase Heater
CLO— Compressor Lockout
COMP — Compressor
CR— Compressor Relay
CS— Current Sensor
DU— Dummy Terminal
FCS— Fan Cycling Switch
FIOP— Factory-Installed Option
FPT— Female Pipe Thread
FS— Flame Sensor
FU— Fuse
GND— Ground
GV— Gas Valve
GVR— Gas Valve Relay
HACR — Heating, Air Conditioning, and Refrigeration
HS— Heat Sensor
HERM — Hermetic
HPS— High-Pressure Switch
I—Ignitor
IA— Indoor Air
IAQ— Indoor-Air Quality
IDM— Induced-Draft Motor
IFC— Indoor-Fan Contactor
IFCB— Indoor-Fan Circuit Breaker
IFM— Indoor-Fan Motor
IGC— Integrated Gas Controller
IRH— Indoor Relative Humidity
LAFC — Low Ambient Fan Control
LPS— Low Pressure Switch
LS— Limit Switch
MGV— Main Gas Valve
OA— Outdoor Air
OAS— Outdoor Air Sensor
OAT— Outdoor-Air Temperature
OFC— Outdoor-Fan Contactor
OFM— Outdoor-Fan Motor
ORH— Outdoor Relative Humidity
PEC— Power Exhaust Contactor
PEM— Power Exhaust Motor
PL— Plug
QC— Quadruple Contactor
QT— Quadruple Terminal
RAS— Return Air Sensor
RAT— Return Air Thermostat
RS— Rollout Switch
SAT— Supply-Air Temperature
TB— Terminal Block
TC— Thermostat Cooling
TH— Thermostat Heating
TRAN — Transformer
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Splice (Marked)
Splice (Field Supplied)
Factory Wiring
Field Control Wiring
Field Power Wiring
Accessory or Optional Wiring
To Indicate Common Potential Only,
Not To Represent Wiring
THERMOSTAT/IGC MARKINGS
BM — Blower MotorRS— Rollout Switch
C—CommonRT— Power Supply
CM — Inducer MotorSS— Speed Sensor
CS — Centrifugal SwitchW—Thermostat Heat
G—FanW1— 1st Stage of Heating
GV — Gas ValveW2— 2nd Stage of Heating
IFO — Indoor Fan OnX—Alarm Output
LI— Line IY1— 1st Stage of Cooling
R—Thermostat PowerY2— 2nd Stage of Cooling
NOTES:
1. Factory wiring is in accordance with the National Electrical Codes. Any field
modifications or additions must be in compliance with all applicable codes.
2. Use 75 C minimum wire for field power supply. Use copper wires for all units.
3. All circuit breakers “Must Trip Amps” are equal to or less than 156% RLA
(rated load amps).
4. Compressor and fan motors are thermally protected. Three-phase motors
protected against primary single phase conditions.
5. The CLO locks out the compressor to prevent short cycling on compressor
overload and safety devices; before replacing CLO, check these devices.
—43—
Fig. 40 — Low Voltage Control Schematic
—44—
Fig. 41 — Power Schematic
—45—
Fig. 42 — Component Arrangement
—46—
TROUBLESHOOTING
I. UNIT TROUBLESHOOTING
Refer to Tables 34-3 6 and Fig. 43.
Table 34 — Cooling Service Analysis
PROBLEMCAUSEREMEDY
Compressor and Condenser
Fan Will Not Start.
Compressor Will Not Start
but Condenser Fan Runs.
Compressor Cycles
(other than normally
satisfying thermostat).
Compressor Operates
continuously.
Excessive Head Pressure.Dirty air filter.Replace filter.
Head Pressure Too Low.Low refrigerant charge.Check for leaks, repair, and recharge.
Excessive Suction Pressure.High heat load.Check for source and eliminate.
Suction Pressure Too Low.Dirty air filter.Replace filter.
LEGEND
TXV — Thermostatic Expansion Valve
Power failure.Call power company.
Fuse blown or circuit breaker tripped.Replace fuse or reset circuit breaker.
Defective thermostat, contactor, transformer, or control
relay.
Insufficient line voltage.Determine cause and correct.
Incorrect or faulty wiring.Check wiring diagram and rewire correctly.
Thermostat setting too high.Lower thermostat setting below room temperature.
Faulty wiring or loose connections in compressor
circuit.
Compressor motor burned out, seized, or internal
overload open.
Defective overload.Determine cause and replace.
Compressor locked outDetermine cause for safety trip and reset lockout.
One leg of 3-phase power dead.Replace fuse or reset circuit breaker.
Refrigerant overcharge or undercharge.Recover refrigerant, evacuate system, and recharge to
Defective compressor.Replace and determine cause.
Insufficient line voltage.Determine cause and correct.
Blocked condenser.Determine cause and correct.
Defective overload.Determine cause and replace.
Defective thermostat.Replace thermostat.
Faulty condenser-fan motor.Replace.
Restriction in refrigerant system.Locate restriction and remove.
Dirty air filter.Replace filter.
Unit undersized for load.Decrease load or increase unit size.
Thermostat set too low.Reset thermostat.
Low refrigerant charge.Locate leak, repair, and recharge.
Air in system.Recover refrigerant, evacuate system, and recharge.
Condenser coil dirty or restricted.Clean coil or remove restriction.
Dirty condenser coil.Clean coil.
Refrigerant overcharged.Recover excess refrigerant.
Faulty TXV.1. Check TXV bulb mounting and secure tightly to suction line.
Air in system.Recover refrigerant, evacuate system, and recharge.
Condenser air restricted or air short-cycling.Determine cause and correct.
Restriction in liquid tube.Remove restriction.
Faulty TXV.1. Check TXV bulb mounting and secure tightly to suction line.
Low refrigerant charge.Check for leaks, repair, and recharge.
Metering device or low side restricted.Remove source of restriction.
Faulty TXV.1. Check TXV bulb mounting and secure tightly to suction line.
Insufficient evaporator airflow.Increase air quantity. Check filter and replace if
Temperature too low in conditioned area.Reset thermostat.
Field-installed filter drier restricted.Replace.
Replace component.
Check wiring and repair or replace.
Determine cause. Replace compressor.
Determine cause.
nameplate.
2. Replace TXV if stuck open or closed.
2. Replace TXV if stuck open or closed.
2. Replace TXV if stuck open or closed.
necessary.
—47—
Table 35 — Heating Service Analysis
Burners Will Not Ignite.Misaligned spark electrodes.Check flame ignition and sensor electrode positioning.
Inadequate Heating.Dirty air filter.Clean or replace filter as necessary.
Poor Flame Characteristics.Incomplete combustion (lack of combustion air)
Burners Will Not Turn Off.Unit is locked into Heating mode for a one minute min-
PROBLEMCAUSEREMEDY
Adjust as needed.
No gas at main burners.Check gas line for air; purge as necessary. After purging gas line of
Water in gas line.Drain water and install drip leg to trap water.
No power to furnace.Check power supply, fuses, wiring, and circuit breaker.
No 24 v power supply to control circuit.Check transformer. Transformers with internal overcurrent protection
Miswired or loose connections.Check all wiring and wire nut connections.
Burned-out heat anticipator in thermostat.Replace thermostat.
Broken thermostat wires.Run continuity check. Replace wires if necessary.
Gas input to unit too low.Check gas pressure at manifold. Clock gas meter for input. If too low,
Unit undersized for application.Replace with proper unit or add additional unit.
Restricted airflow.Clean filter, replace filter, or remove any restrictions.
Blower speed too low.Install alternate motor, if applicable, or adjust pulley to increase fan
Limit switch cycles main burners.Check rotation of blower, thermostat heat anticipator settings, and
Too much outdoor air.Adjust minimum position.
results in:
Aldehyde odors, CO, sooting flame, or floating flame.
imum.
air, allow gas to dissipate for at least 5 minutes before attempting to
relight unit.
Check gas valve.
require a cool-down period before resetting. Check 24-v
circuit breaker; reset if necessary.
increase manifold pressure or replace with correct orifices.
speed.
temperature rise of unit. Adjust as needed.
Check economizer operation.
Check all screws around flue outlets and burner compartment.
Tighten as necessary.
Cracked heat exchanger.
Overfired unit — reduce input, change orifices, or adjust gas line or
manifold pressure.
Check vent for restriction. Clean as necessary.
Check orifice to burner alignment.
Wait until mandatory one minute time period has elapsed or power to
unit.
Table 36 — IGC Board LED Alarm Codes
LED FLASH
CODE
OnNormal Operation———
OffHardware FailureNo gas heating.—Loss of power to the IGC. Check 5 amp fuse on IGC, power
1 FlashIndoor Fan On/Off Delay
2 Flashes Limit Switch FaultGas valve and igniter Off.
3 Flashes Flame Sense FaultIndoor fan and inducer On.Flame sense normal.
4 Flashes Four Consecutive Limit
5 Flashes Ignition FaultNo gas heating.Heat call (W) Off.
6 Flashes Induced Draft Motor FaultIf heat off: no gas heating.
7 Flashes Rollout Switch LockoutGas valve and igniter Off.
8 Flashes Internal Control LockoutNo gas heating.Power reset.IGC has sensed internal hardware or software error. If fault
9 Flashes Temporary Software LockoutNo gas heating.1 hour auto reset, or power
IGC— Integrated Gas Unit Control
LED— Light-Emitting Diode
LEGENDNOTES:
DESCRIPTION
Modified
Switch Fault
ACTION TAKEN BY
CONTROL
5 seconds subtracted from On
delay.
5 seconds added to Off delay
(3 min max).
Indoor fan and inducer On.
No gas heating.Heat call (W) Off.
If heat on: gas valve Off and
inducer On.
Indoor fan and inducer On.
RESET METHODPROBABLE CAUSE
Power reset.High temperature limit switch opens during heat exchanger
Limit switch closed, or heat
call (W) Off.
Power reset for LED reset.
Power reset for LED reset.
Power reset for LED reset.
Inducer sense normal, or
heat call (W) Off.
Power reset.Rollout switch has opened. Check gas valve operation.
reset.
1. There is a 3-second pause between alarm code displays.
2. If more than one alarm code exists, all applicable alarm codes will be displayed
in numerical sequence.
3. Alarm codes on the IGC will be lost if power to the unit is interrupted.
to unit, 24V circuit breaker, transformer, and wiring to the
IGC.
warm-up period before fan-on delay expires.
High temperature limit switch opens within
10 minutes of heat call (W) Off.
See Limit Switch Fault.
High temperature limit switch is open. Check the operation
of the indoor (evaporator) fan motor. Ensure that the supply-air temperature rise is within the range on the unit
nameplate. Check wiring and limit switch
operation.
The IGC sensed a flame when the gas valve should be
closed. Check wiring, flame sensor, and gas valve operation.
4 consecutive limit switch faults within a single call for heat.
See Limit Switch Fault.
Unit unsuccessfully attempted ignition for 15 minutes. Check
igniter and flame sensor electrode spacing, gaps, etc. Check
flame sense and igniter wiring. Check gas valve operation
and gas supply.
Inducer sense On when heat call Off, or inducer sense Off
when heat call On. Check wiring, voltage, and operation of
IGC motor. Check speed sensor wiring to IGC.
Check induced-draft blower wheel is properly secured to
motor shaft.
is not cleared by resetting 24 v power, replace the IGC.
Electrical interference is disrupting the IGC software.
—48—
LEGEND
IDM — Induced-Draft Motor
IGC — Integrated Gas Unit Controller
NOTE: Thermostat Fan Switch in the
“AUTO” position.
Fig. 43 — IGC Control (Heating and Cooling)
—49—
II. ECONOMI$ER IV TROUBLESHOOTING
See Table 37 for EconoMi$er IV logic.
A functional vi ew of the Econ oMi$er IV is shown in Fig. 44.
Typical settings, sensor ranges, and jumper positions are
also shown. An EconoMi$er IV simulator program is available from Bryant to help with EconoMi$er IV training and
troubleshooting.
A. EconoMi$er IV Preparation
This procedure is used to prepare the EconoMi$er IV 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 EconoMi$er IV.
IMPORTANT:
Be sure to record the positions of all potentiometers
before starting troubleshooting.
1. Disconnect power at TR and TR1. All LEDs should be
off. Exhaust fan contac ts 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.
and +.
R
and +.
O
7. If connected, remove sensor from terminals S
Connect 1.2 kilo-ohm 4074EJM checkout resistor
across terminals S
and +.
O
8. Put 620-ohm resistor across terminals S
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.
B. Differential Enthalpy
To check differential enthalpy:
1. Make sure Econ o Mi $er IV preparatio n pr o ce dur e h as
been performed.
2. Place 620-ohm resistor across S
3. Place 1.2 kilo-ohm resistor across S
and +.
O
and +. The Free
R
Cool LED should be lit.
4. Remove 620-ohm resistor across S
and +. The Free
O
Cool LED should turn off.
5. Return EconoMi$er IV settings and wiring to normal
after completing troubleshooting.
C. Single Enthalpy
To check single enthalpy:
1. Make sure Econ o Mi $er IV preparatio n pr o ce dur e h as
been performed.
2. Set the enthalpy potentiometer to A (fully CCW). The
Free Cool LED should be lit .
3. Set the enthalpy potentiometer to D (fully CW). The
Free Cool LED should turn off.
4. Return EconoMi$er IV settings and wiring to normal
after completing troubleshooting.
D. DCV (Demand Controlled Ventilation) and Power
Exhaust
To check DCV and Power Exhaust:
1. Make sure Econ o Mi$ er I V pr epa ra tio n proce dure has
been performed.
2. Ensure terminals A Q and AQ 1 a r e op en . 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 a ctua tor s hou ld dri ve to be tween
90 and 95% open.
4. Turn the Exhaust potentiometer CW until the
Exhaust LED turns off. The LED should turn off
when the potentiometer is approximately 90%. The
actuator should remain in position.
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 afte r the Exhaust
LED turns on.
7. Return EconoMi$er IV settings and wiring to norm al
after completing troubleshooting.
E. DCV Minimum and Maximum Position
To check the DCV minimum and maximum position:
1. Make sure Econ o Mi$ er I V pr epa ra tio n proce dure has
been performed.
2. Connect a 9-v battery to AQ (positive node) and AQ1
(negative node). Th e 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 actua tor should drive to betwee n 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 EconoMi$er IV settings and wiring to norm al
after completing troubleshooting.
F. Supply-Air Input
To check supply-air input:
1. Make sure Econ o Mi$ er I V pr epa ra tio n proce dure has
been performed.
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.
—50—
4. Remove the jumper across T and T1. The actuator
should drive fully closed.
5. Return EconoMi$er IV settings and wiring to normal
after completing troubleshooting.
G. EconoMi$er IV Troubleshooting Completion
This procedur e i s used to retur n t h e E c o noMi$er IV to ope r ation. No troubleshooting or testing is done by performing the
following proced ur e.
1. Disconnect power at TR and TR1.
2. Set enthalpy potentiometer to previous setting.
3. Set DCV maximum position po tentiometer to previous setting.
Table 37 — EconoMi$er IV Input/Output Logic
INPUTSOUTPUTS
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 determines Occupied/Unoccupied setting:
24 vac (Occupied), no power (Unoccupied).
**Modulation is based on the supply-air sensor signal.
††Modulation is based on the DCV signal.
High
(Free Cooling LED Off)
Low
(Free Cooling LED On)
High
(Free Cooling LED Off)
Low
(Free Cooling LED On)
Enthalpy*
OutdoorReturn
LowOn OnOnOnMinimum positionClosed
HighOn OnOnOffModulating** (between min.
LowOn OnOnOnModulating†† (between min.
HighOn OnOnOffModulating***Modulating†††
Y1 Y2
On OffOnOff
Off OffOffOff
On OffOffOff
Off OffOffOffMinimum positionClosed
On OffOnOff
Off OffOffOff
On OffOffOff
Off OffOffOff
4. Set minimum position, DCV set point, and exhaust
potentiometers to previous settings.
5. Remove 620-ohm resistor from terminals S
R
6. Remove 1.2 kilo-ohm checkout resistor from terminals S
and +. If used, reconnect sensor from termi-
O
nals 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. Remov e jumper from P to P1. Reconn ect device at P
and P1.
11. Apply power (24 vac) to terminals TR and TR1.
CompressorN Terminal†
Stage1Stage
2
position and full-open)
position and DCV maximum)
***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-air signal).
†††Modulation is based on the greater of DCV and supply-air sensor
signals, between closed and either maximum position (DCV) or fully
open (supply-air signal).