Reznor MAPS III User Manual

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Page 1

Form O-MAPSIII Cabinet D (Version D)

CQS

Obsoletes Form O-MAPSIII Cabinet D (Version C)

Operation / Maintenance / Service

Applies to: Models RCB, RDB, RDCB,

™

RDDB, RECB, and REDB

Cabinet "D" Sizes

R-410A

Refrigerant

CQS

DANGER

This unit contains R-410A high pressure refrigerant. Hazards exist that could result in personal injury or death. Installation, maintenance, and service should

only be performed by an HVAC technician qualied in R-410A refrigerant and

using proper tools and equipment. Due to much higher pressure of R-410A refrigerant, DO NOT USE service equipment or tools designed for R22 refrigerant.

IMPORTANT: Do not release refrigerant to the atmosphere! If required service procedures include the adding or removing of refrigerant, the service technician must comply with all federal, state and local laws. The procedures discussed

in this manual should only be performed by a qualied HVAC technician.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 1

Page 2

Table of Contents

1.0 General ................................................................2

2.0 Maintenance Requirements .......................... 3-5

2.1 Maintenance Schedule ........................................3

2.2 Control Locations .................................................4

2.3 MAPSIII D Cabinet Sizes .....................................5

3.0 Maintenance/Service Procedures .............. 5-21

3.1 Filters ..................................................................5

3.2 Drive Components ...............................................6

3.3 Condenser Fans ..................................................6

3.4 Coil Maintenance .................................................7

3.5 Check Refrigerant Pressure and

Temperatures (subcooling and superheat) .........9

3.6 Compressor Maintenance and Replacement ....10

3.7 Thermostatic Expansion Valves .........................18

3.8 Dampers and Damper Controls .........................19

3.9 Other Controls ...................................................19

1.0 General

This booklet includes operation, maintenance, and service information on the MAPS®III Cabinet D Size systems. Before beginning any procedure, carefully review the information, paying particular attention to the warnings. Handling of refrigerant should only

be performed by a certied HVAC technician with knowledge of the requirements of R-410A refrigerant and in compliance with all codes and requirements of authorities

having jurisdiction. The instructions in this manual apply to the following MAPS®III models.

4.0 Gas Heat Section Maintenance - Models

RDCB and RDDB ........................................ 21-33

4.1 Heat Exchanger, Burner, and Venter

Maintenance .....................................................21

4.2 Gas Heat Section Controls ................................26

4.3 Gas Train ...........................................................30

4.4 Other Gas Heat Section Controls ......................32

5.0 Electric Heat Section Maintenance -

Models RECB and REDB ........................... 33-34

6.0 Troubleshooting ......................................... 35-42

6.1 Troubleshooting - All Models..............................35

6.2 Troubleshooting the Heat Section .....................36

INDEX ......................................................................43

REFERENCES .......................................................44

NOTE: To conrm that this

booklet is applicable, see list of D Cabinet Sizes in Paragraph 2.3, page 5.

Denitions of Hazard

Intensity Levels used in this Manual

Model Description RCB

RDCB

RECB

RDB

RDDB

REDB

There are warning labels on the unit and throughout this manual. For your safety, comply with all warnings during installation, operation, and service of this system. See

denitions of Hazard Intensity Levels of warnings below.

Makeup Air Cooling Packaged System, 5200-13000 CFM

Makeup Air Cooling Packaged System, 5200-13000 CFM, with Gas Heat Section (500-1600 MBH)

Makeup Air Cooling Packaged System, 5200-13000 CFM, with Electric Heat Section (120 & 180 kw)

Makeup Air Cooling and Re-heat Pump Reheat Cycle Packaged System, 5200-13000 CFM

Makeup Air Cooling and Re-heat Pump Reheat Cycle Packaged System, 5200-13000 CFM, with a Gas Heat Section (500-1600 MBH)

Makeup Air Cooling and Re-heat Pump Reheat Cycle Packaged System, 5200-13000 CFM, with Electric Heat Section (120 & 180 kw)

HAZARD INTENSITY LEVELS

1. DANGER: Failure to comply will result in severe personal injury or death and/or property damage.

2. WARNING: Failure to comply could result in severe personal injury or death and/or property damage.

3. CAUTION: Failure to comply could result in minor personal injury and/or property damage.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 2

Page 3

2.0 Maintenance Requirements

This unit will operate with a minimum of maintenance. To ensure long life and satisfactory performance, a system that is operating under normal conditions should be inspected according to the Maintenance Schedule. If in an area where an unusual amount of dust or soot or other impurities are present in the air, more frequent inspection is recommended.

Refer to the illustration in FIGURE 1, page 4, and follow the instructions in the referenced paragraphs to maintain this equipment. Maintenance requirements and procedures apply to all Models unless noted.

NOTE: If replacement parts are required, use only factory-authorized parts.

For information, go to www.ReznorHVAC.com or call 800-695-1901

WARNING

Lock power OFF before performing all maintenance procedures (except where power is required such as checking refrigerant pressure and temperature). Lock disconnect switch in OFF position. If the system has a heat section, when you turn off the power supply, turn off the gas. See Hazard Levels, page 2.

2.1 Maintenance Schedule

Monthly

□ Inspect lters; clean or replace as needed. See Paragraph 3.1. □ Inspect the condensate drain; clean as needed. For information, see Form

I-MAPSIII&IV, Paragraph 6.2.

Semi-Annually

□ Inspect the unit blower plenum fan and belt. Check belt for tension, wear, and

alignment. Adjust or replace as needed. Clean dirt from blower and motor. See Paragraph 3.2.

Annually

NOTE: Redo the cooling startup procedures when the cooling season begins. Refer

to Startup instructions in the installation manual, Form I-MAPSIII&IV, Paragraph 10.0.

Beginning of the cooling season or more frequently in year-round cooling climate (applies to all Models):

□ Inspect the wiring for any damaged wire. Replace damaged wiring. □ Inspect the condensate drain pan. Clean the coil cabinet, the drain pan, and ll the

trap. □ Inspect/clean condenser fans. See Paragraph 3.3. □ Inspect/clean all coils. See Paragraph 3.4. □ Check compressor operation. See Paragraph 3.6. □ Check refrigerant pressure and temperatures (superheat and subcool). These

checks are done when the system is operating. See Paragraph 3.5.

Models RDCB & RDDB with a gas heat section (beginning of the heating season) - See Section 4.0.

□ Clean all dirt and grease from the combustion air openings and the venter

assembly. □ Check the heat exchanger, burner, and venter for scale, dust, or lint accumulation.

Clean as needed. □ Check the gas valves to ensure that gas ow is being shutoff completely.

Models RECB & REDB with an electric heat section (beginning of the heating season) - See Section 5.0.

□ Check the wiring connections. □ Check the heat section and electric elements for dust or lint accumulation.

Carefully clean as needed.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 3

Page 4

2.0 Maintenance Requirements (cont'd)

High Voltage Panel

Control

Transformer

Distribution

Block

Distribution Block

Grounding

Lug

Terminal Blocks

Phase Loss Monitor

Contactor (Condenser Fan B & C)

Contactor (Condenser Fan A & D)

Contactor (Reheat Compressor E)

Contactor (Compressor D)

Contactor (Compressor C)

Contactor (Compressor B)

Contactor (Compressor A)

Motor Starter

Rear View

Side View

Front

View

75VA transformers

Optional Dirty

Filter Switch

Digital

Controller

Display

Wire Harness

Assembly

Optional

Relays

and Bases

Low Voltage Panel

Control Compartment Access Door

Heater Controls Access Door

Filter Access

Coil Access

Fan and Motor

Access

Condenser Section

2.2 Control Locations

FIGURE 1 - Access Panels and High and Low Voltage Control Locations

Door Hinge

Locked Unlocked

The lter, coil, and fan/motor cabinet

doors can be opened from the left or right. On the side of the door to be opened, unlock the two hinges with an allen key. Pull out unlocked "fronts" of hinges to 90 degrees to expose handles needed to open the door. Re-lock hinges when door is closed.

High Voltage Panel (behind low voltage panel; post is removed for less restricted view)

Low Voltage Panel (hinged; swings out to access rear side and high voltage panel behind)

Gas Heat Section Control Panel

(See Para 4.2.1.)

NOTE: Electric heat Models RECB and REDB have additional electrical panels in

the heat section; see

Paragraph 5.0, page

33.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 4

Page 5

(2) P/N 104102,

16x16x1

(2) P/N 104102,

16x16x1

(2) P/N 104102,

16x16x1

(2) P/N 104102,

16x16x1

(2) P/N 104102,

16x16x1

(2) P/N 104102,

16x16x1

(2) P/N 101609,

16x25x1

(2) P/N 101609,

16x25x1

(2) P/N 101609,

16x25x1

1) Loosen wing nuts and slide clamp.

2) Remove filters.

3) Repeat for all filters.

4) Wash and dry filters.

5) Re-install filters in hood. Be sure wing nuts are tight and filters secure.

Filters in Hood - Cabinet D

2.3 MAPSIII D Cabinet Sizes

Model

RCB

360

480

600

720

Model

RDB

418

444

484

538

564

602

658

684

722

804

842

Cabinet

Size

Cabinet

Size

Model RDCB

360

480

600

720

Model RDDB

418

444

484

538

564

602

658

684

722

804

842

Gas Heat Section Size

-500 -600 -700 -800 -1000 -1200 -1400 -1600

D D D D D D D D

Gas Heat Section Size

-500 -600 -700 -800 -1000 -1200 -1400 -1600

D D D D D D D D

Electric Heat Section

RECB120 RECB180

D D

Electric Heat Section

REDB120 REDB180

D D

3.0 Maintenance/

Service Procedures

3.1 Filters

The lter section is equipped with 4 inches of pleated disposable or permanent aluminum lters. To remove lters, open the door and slide lters out.

If equipped with permanent aluminum lters, there are sixteen 2"x20"x24" lters. Remove the lters, wash, rinse, allow to dry, and slide them back in the cabinet. The P/N for replacement or extra lter is 223065; quantity is 16.

If equipped with pleated disposable lters, there are eight 4"x20"x24" lters, either MERV8 or MERV13.. Replace dirty lters. Exposure to humid makeup air can accelerate lter degradation. Systems with disposable lters require more frequent lter inspection. The P/N for one replacement or extra MERV8 lter is 222480; quantity required is 8. The P/N for one replacement or extra MERV13 lter is 260828; quantity required is 8.

Dirty Filter Switch - If equipped with a dirty lter switch, check the condition of the

sensing tubes to be sure that they are not blocked. Check the wiring connections. To

set a new switch, see Installation Form I-MAPSIII&IV, Paragraph 8.1, Replacement

switch is P/N 105507.

Permanent Filters in the Outside Air Hood

If equipped with an outside air hood, there are 1" permanent, aluminum lters at the entrance of the hood. The lters act as a moisture eliminator and bird screen.

When inspecting the inlet air lters, inspect the outside air hood lters. If cleaning is needed, remove the lters, clean, rinse, dry and re-install. NOTE: If it is more conve- nient to keep an extra clean set of lters, lter sizes and part numbers are shown in

the illustration.

FIGURE 2 - Removing Filters from Outside Air Hood

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 5

Page 6

3.0 Maintenance/

2-1/2” (63.5mm)

Fan and Motor Assembly showing Fan Blade Position

Cross-section of Installed Fan and Motor Assembly showing Cabinet Top

1.76” (44.7mm)

Top of Fan Blade

to Top of the

Cabinet Top Panel

Service Procedures (cont'd)

3.2 Drive Components

Bearings - Bearings with a grease tting should be lubricated twice a year with a high

temperature, moisture-resistant grease. (Type NLGI-1 or -2 standard grease is recommended.) Be sure to clean the grease tting before adding grease. Add grease with a

handgun until a slight bead of grease forms at the seal. Be careful not to unseat the seal by over lubricating. NOTE: If unusual environmental conditions exist (tempera-

tures below 32°F or above 200°F; moisture; or contaminants), more frequent lubrication is required.

CAUTION: If the blower is unused for more than three months,

bearings with a grease tting should be purged with new grease

prior to start-up.

Setscrews - Check all of the setscrews (bearing/blower hubs and pulleys). Torque pul-

ley setscrews a minimum of 110 in-lb to 130 in-lb maximum.

A bearing hub setscrew for a 1-3/8" to 1-3/4" shaft requires a 5/16" socket and a tightening torque of 165 in-lbs.

Belts - Check belt for proper tension and wear. Adjust belt tension as needed. Replace worn belts.

Blower systems are equipped with either Power Twist Plus

belt. The linked belts are designed in sections allowing for easy sizing and adjustment. The belt is sized at the factory for the proper tension. If the belt needs adjustment, the recommended method of shortening the belt length is to count the number of links and remove one link for every 24. (A link is made up of two joining sections of belt. For easier removal of links, turn the belt inside out. But be sure to turn it back before installing.)

If equipped with a solid belt, adjust the belt tension by turning the adjusting screw on

the motor base until the belt can be depressed 1/2" (13mm) on each side. After correct tension is achieved, re-tighten the locknut on the adjustment screw.

Proper belt tension is important to the long life of the belt and motor. Be sure belts are aligned in the pulleys. If a belt is removed or replaced, be sure to align

directional arrows on the belt to the proper drive rotation.

Motor and Blower - Inspect the motor mounts periodically. Remove dust and dirt accumulation from the motor and wheel.

The blower has cast iron, pillowblock, sealed bearings. Under most operating conditions, re-lubrication is unnecessary. If lubrication is required, use a lubricant compatible to Shell Alvania #2 (lithium base - Grade 2). Operating temperature range is -30 to 230°F.

"D" size cabinets have plenum fan blowers which have an extension to the grease tting on the side of the fan assembly.

If any drive parts need to be replaced, use only factory-authorized replacements designed for the application.

linked blower belt or a solid

3.3 Condenser Fans

FIGURE 3 - Condenser Fan Assembly Dimensions and Rotation

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 6

Depending on the size, there are two, three, or four fans in the condenser section. If parts need to be replaced, use only factory authorized replacement parts.

See FIGURE 3 for assembled dimensions and proper fan rotation direction.

Fan rotation is clockwise

Page 7

3.4 Coil

Condenser Coils by Circuit

5 ton MC Coil

10 ton MC Coil

Inlet 1 Ø 0.879

Inlet 2 Ø 0.879

Outlet Ø 0.879

Discharge

Line Ø 0.500

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Liquid Line Ø 0.875 Liquid Line Ø 0.875

Liquid Line Ø 0.500

Filter Drier

(See compressor locations on page 12.)

Suction Line Ø 1.375

Suction Line Ø 0.875

Suction Line Ø 1.375

RCB/RDCB/RECB 360 and RDB/RDDB/REDB 418, 444, and 484

(To TXV valves and

Distributors on

Evaporator Coils)

15 ton MC Coil

Inlet

Ø 0.506

Outlet Ø 0.506

Inlet

Ø 0.879

Outlet Ø 0.879

Outlet Ø1.380

Outlet Ø 0.879

Maintenance

Inspect all cooling system coils at the beginning of the cooling season or more often if

needed. Follow the cleaning instructions below. If additional cleaning is required or if a

coil must be removed for any reason, consult the factory. Be prepared to provide rating plate and installation information.

Condenser Coil Access - The bank of condensing coils is located on top of the unit.

Condenser Coil Cleaning Instructions:

1) Verify that the electrical power has been turned off and the disconnect switch

locked.

2) Use a soft brush to remove any dirt and debris from the coils.

3) Spray with cold or warm (not hot) water and a cleaning solution (non-acid based coil cleaner is recommended). Due to possible damage to the coil, do not use high pressure spray.

4) When clean, rinse with cool, clean water.

Evaporator Coil Access - The evaporative coils can be accessed by opening the coil cabinet door.

Inspect coils for debris, dirt, grease, lint, pollen, mold, or any element which would

obstruct heat transfer or airow. Inspect coils and tubing for physical damage. Inspect

feeders, piping connections, coil headers, and return bends for signs of fatigue, rubbing, and physical damage.

Clean the coils annually, or more often if needed. Use the proper tools and follow the instructions carefully to avoid damaging the coil. Use of a non-acid based coil cleaner is recommended. Due to possible damage to the coil, high pressure spray is not recommended.

FIGURE 4 - Coil Circuits (Views are from the control side of the system.)

Evaporator Coil Cleaning Instructions:

1) Verify that the electrical power has been turned off and the disconnect switch

locked.

2) Open the access panels.

3) Use a soft brush to remove any dirt and debris from both sides of a coil.

4) Spray with cold or warm (not hot) water and a cleaning solution (non-acid based coil cleaner is recommended). Due to possible damage to the coil, high pressure spray is not recommended. First spray the leaving airow side, then the inlet

airow side.

As much as possible, spray the solution perpendicular to the face of the coil. Follow the instructions on the cleaning solution. When cleaning process is

complete, rinse both sides with cool, clean water.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 7

Page 8

3.0 Maintenance/Service Procedures (cont'd)

Condenser Coils by Circuit

ADA

10 ton MC Coil

5 ton MC Coil

10 ton MC Coil

15 ton MC Coil

Inlet 1 Ø 0.881

Inlet 1 Ø 0.879

Inlet Ø 0.881

Inlet 2 Ø 0.881

Inlet 2 Ø 0.879

Inlet 1 Ø 0.881

Inlet 2 Ø 0.881

Outlet Ø 0.881

Outlet Ø 0.879

Outlet Ø 0.881

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Discharge

Line Ø 0.500

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Liquid Line Ø 0.875

Liquid Line Ø 0.875 Liquid Line Ø 0.875

Liquid Line Ø 0.500

Liquid Line Ø 0.875

Filter Drier

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Discharge

Line Ø 0.875

Liquid Line Ø 0.875

Filter Drier

Outlet Ø 0.881

Inlet Ø 0.881

Inlet 2 Ø 0.881

Inlet 1 Ø 0.881

Inlet 2 Ø 0.881

Inlet 1 Ø 0.881

Inlet Ø 0.881

10 ton MC Coil

15 ton MC Coil

(See compressor locations on page 12.)

Evaporator Coils by Circuit (interlaced)

All three outlets Ø 1.380

All four outlets Ø 1.380

Suction Line Ø 1.375

Suction Line Ø 0.875

Suction Line Ø 1.375

RCB/RDCB/RECB 480 and RDB/RDDB/REDB 538, 564, and 602

RCB/RDCB/RECB 360 and RDB/RDDB/REDB 418, 444, and 484

RCB/RDCB/RECB 600 and RDB/RDDB/REDB 658, 684, and 722

Suction Line Ø 1.375

(To TXV valves and

Distributors on

Evaporator Coils)

(To TXV valves and

Distributors on

Evaporator Coils)

(To TXV valves and Distributors

on Evaporator Coils)

Condenser Coils by Circuit

15 ton MC Coil

Inlet

Ø 0.506

Outlet Ø 0.506

Inlet

Ø 0.879

Outlet Ø 0.879

Outlet Ø1.380

Outlet Ø 0.879

3.4 Coil Maintenance (cont'd)

FIGURE 4 (cont'd) - Coil Circuits (Views are from the control side of the system.)

RCB/RDCB/RECB 720 and RDB/RDDB/REDB 722, 804, and 842

Evaporator Coils by Circuit (interlaced)

All four

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 8

outlets Ø 1.380

Suction Line Ø 1.375

Filter Drier

on Evaporator Coils)

(To TXV valves and Distributors

15 ton MC Coil

Inlet 2 Ø 0.881

Inlet 1 Ø 0.881

Liquid Line Ø 0.875

(See compressor locations on page 12.)

Condenser Coils by Circuit

Inlet 1

Ø 0.881

15 ton

Inlet 2

Outlet Ø 0.881

Discharge

Line Ø 0.875

Liquid Line Ø 0.875

MC Coil

Outlet Ø 0.881

Ø 0.881

Discharge

Line Ø 0.875

Inlet 1 Ø 0.881

15 ton

MC Coil

Inlet 2 Ø 0.881

Discharge

Outlet Ø 0.881

Line Ø 0.875

15 ton MC Coil

Outlet Ø 0.881

Inlet 2 Ø 0.881

Inlet 1 Ø 0.881

Discharge

Line Ø 0.875

Page 9

3.5 Check Refrigerant Pressure and Temperatures (subcooling and superheat)

DANGER

The refrigeration circuits are high pressure systems. Hazards exist that could result in personal injury or death. Removal, installation, and service of this scroll compressor must be

performed by a technician qualied in R-410A refrigerant.

DO NOT USE tools or service equipment designed for R22 refrigerant. See Hazard Levels, page 2.

Check SUBCOOLING

Measure and record temperature and pressure of the liquid line at the condenser coil

outlet.

STEP 1) Record Measurements: Temperature = ________°F (°C) and

Pressure = ________ psig

STEP 2) From Temperature/Pressure Conversion Chart (page 10), convert

Measured Pressure (STEP 1) to ________°F (°C)

STEP 3) Subtract Measured Temperature (STEP 1) from Temperature from

Conversion Chart (STEP 2): ________°F (°C) - ________°F (°C) =

________°F (°C) degrees of Subcooling

Recommended subcooling with outdoor temperature range of 70

to 95°F (21 to 35°C) is 10 to 12 degrees F (5.6 to 6.7 degrees C).

Too much subcooling indicates a refrigerant overcharge. To reduce the subcooling,

remove excess refrigerant. Too little subcooling indicates a refrigerant undercharge. To increase subcooling, slowly add R-410A refrigerant.

WARNING

Do not release refrigerant to the atmosphere. When adding or removing

refrigerant, the qualied technician must comply with all national, state/

province, and local laws.

Determine SUPERHEAT

Measure and record temperature (insulate probe from surrounding air temperature) and pressure in the suction line at the compressor inlet.

STEP 1) Record Measurements: Temperature = _______°F (°C) and Pressure

= _______ psig

STEP 2) From Temperature/Pressure Conversion Chart (below), convert

Measured Pressure (STEP 1) to ________°F (°C)

STEP 3) Subtract Measured Temperature (STEP 1) from Temperature from

Conversion Table (STEP 2): _______°F (°C) - ________°F (°C) =

________°F (°C) degrees of Superheat

Recommended superheat at is 8 to 12 degrees F (4.5 to 6.7 degrees C).

Typically, too much superheat indicates that the evaporator coil is undercharged. Too little superheat typically indicates that the evaporator coil is overcharged and

may potentially ood liquid refrigerant to the compressor. To reduce the superheat,

adjust the thermal expansion valve by turning the adjusting stem counterclockwise. To increase the superheat, adjust the thermal expansion valve by turning the adjusting stem clockwise.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 9

Page 10

3.0 Maintenance/Service Procedures (cont'd)

3.5 Check Refrigerant Pressure and Temperatures (subcooling and superheat) (cont'd)

Temperature/Pressure Conversion Chart

R-410A Refrigerant R-410A Refrigerant R-410A Refrigerant R-410A Refrigerant

Pressure Temperature Pressure Temperature Pressure Temperature Pressure Temperature

PSI °F °C PSI °F °C PSI °F °C PSI °F °C

1.8 -55 -48.3 56.4 6 -14.4 93.5 28 -2.2 143.3 50 10.0

4.3 -50 -45.6 57.9 7 -13.9 95.5 29 -1.7 156.6 55 12.8

7.0 -45 -42.8 59.3 8 -13.3 97.5 30 -1.1 170.7 60 15.6

10.1 -40 -40.0 60.8 9 -12.8 99.5 31 -0.6 185.7 65 18.3

13.5 -35 -37.2 62.3 10 -12.2 101.6 32 0.0 201.5 70 21.1

17.2 -30 -34.4 63.9 11 -11.7 103.6 33 0.6 218.2 75 23.9

21.4 -25 -31.7 65.4 12 -11.1 105.7 34 1.1 235.9 80 26.7

25.9 -20 -28.9 67.0 13 -10.6 107.9 35 1.7 254.6 85 29.4

27.8 -18 -27.8 68.6 14 -10.0 110.0 36 2.2 274.3 90 32.2

29.7 -16 -26.7 70.2 15 -9.4 112.2 37 2.8 295.0 95 35.0

31.8 -14 -25.6 71.9 16 -8.9 114.4 38 3.3 316.9 100 37.8

33.9 -12 -24.4 73.5 17 -8.3 116.7 39 3.9 339.9 105 40.6

36.1 -10 -23.3 75.2 18 -7.8 118.9 40 4.4 364.1 110 43.3

38.4 -8 -22.2 77.0 19 -7.2 121.2 41 5.0 389.6 11 5 46.1

40.7 -6 -21.1 78.7 20 -6.7 123.6 42 5.6 416.4 120 48.9

43.1 -4 -20.0 80.5 21 -6.1 125.9 43 6.1 444.5 125 51.7

45.6 -2 -18.9 82.3 22 -5.6 128.3 44 6.7 474.0 130 54.4

48.2 0 -17.8 84.1 23 -5.0 130.7 45 7.2 505.0 135 57.2

49.5 1 -17.2 85.9 24 -4.4 133.2 46 7.8 537.6 140 60.0

50.9 2 -16.7 87.8 25 -3.9 135.6 47 8.3 571.7 145 62.8

52.2 3 -16.1 89.7 26 -3.3 138.2 48 8.9 607.6 150 65.6

53.6 4 -15.6 91.6 27 -2.8 140.7 49 9.4 645.2 155 68.3

55.0 5 -15.0

3.6 Compressor

Maintenance and Replacement

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 10

The refrigeration circuits are high pressure systems. Hazards exist that could result in personal injury or death. It is therefore required that the removal and installation of this

scroll compressor be performed by a technician qualied in

R-410A refrigerant. See Hazard Levels, page 2.

Never use oxygen to pressurize a refrigeration system. Oxygen can explode on contact with oil and could result in personal injury or death. When using high pressure gas such as nitrogen for this purpose, ALWAYS USE A PRESSURE REGULATOR that can control the pressure down to 1 or 2 psig. Failure to use a regulator will result in extremely high pressure which could exceed the burst pressure of the compressor or other system components and result in personal injury or death. See Hazard Levels, page 2.

DANGER

Page 11

WARNINGS

For your safety, wear eye protection, gloves, and protective clothing

when handling refrigerant and oil and when brazing. Have a re

extinguisher nearby. See Hazard Levels, page 2.

Compressor Handling

Do not lift compressor by copper tubing. To prevent internal damage, compressors

must ALWAYS be held upright.

The following instructions include major points of consideration that will ensure proper installation and protect you from potential personal injury. Please use the following 13 steps as a checklist, taking each item in order before proceeding to the next. If more

information is required, contact the Reznor Service Department for Reznor® products.

WARNING

To avoid electrical shock, power to the com-pressor(s) MUST REMAIN OFF during performance of Steps 1 through 9 below. LOCK DISCONNECT SWITCH OFF (open).

Step 1. Verify Proper Application

Verify that the replacement compressor is identical to the model being replaced.

All system components are matched to the compressor. Replacing a compressor

with a model other than the one specied for replacement will void the product

warranty. See part numbers for R-410A compressors on page 13.

Step 2. Determine Cause of Initial Failure and Remove the

Compressor

In order to prevent a second failure, the cause of the original failure must be

determined. Identify the cause and make the necessary repairs.

CAUTION: DO NOT LIFT compressor by copper tubing; damage will occur. Compressor must remain upright.

WARNING

Wear eye protection and gloves when handling refrigerant or oil and when brazing.

a) BEFORE REMOVING THE FAULTY COMPRESSOR, remove refrigerant charge

using proper recovery procedures. Call 1-800-441-9450 for the name of the nearest Dupont authorized distributor or 1-800-ASK-KLEA (IGI) for information on their refrigerant reclaim programs.

b) Disconnect wires. All compressor wiring is connected using a black molded

plastic plug. Remove the plug from the compressor.

c) Open access ports so that pressure does not build up in the system. Before

unbrazing stubs from the compressor, cut suction and discharge tubing with a tubing cutter.

WARNING

Have a re extinguisher near. The compressor contains oil. There is a risk of re when unbrazing stubs.

Use a high temperature torch to disconnect the suction line and the discharge line from the compressor.

d) Remove the mounting bolts and the compressor. Save the mounting hardware

to attach the grommets and sleeves shipped with the replacement compressor.

e) To test for acid and to assure excess oil does not remain in the circuit, remove

oil from the failed compressor. Measure the amount of oil.

CAUTION: In addition to the required eye protection and gloves, care should be taken in handling POE oil because it may cause damage to

certain plastics and roong materials. See Hazard Levels, page 2.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 11

Page 12

3.0 Maintenance/

Reheat compressor in Models RDB and RDDB

DH or E

Condenser

Bank B & C

Condenser

Bank A & D

Service Procedures (cont'd)

3.6 Compressor Maintenance (cont'd)

Step 2. Determine Cause of Initial Failure (cont'd)

Compressor Oil Charge (POE Oil)

Compressor

Model

ZP57K3E 1538 52

ZP83KCE 1656 56

ZP120KCE 3135 106

ZP182KCE 3135 106

cc oz

Important NOTES: These R-410A compressors use a polyolester (POE) lubricant. Types of recommended POE oil are Copeland Ultra 22 CC, Copeland Ultra

32 CC, Copeland Ultra 32-3MAF, Mobil EAL™, Arctic 22 CC, Uniqema Emkarate RL32CF, or Uniqema RL32-3MAF.

POE oil absorbs moisture much quicker and to a greater degree than standard mineral oil. The compressor must not be left open longer than 15 minutes during replacement. During installation the system must be swept with an inert gas such as dry nitrogen to keep moisture from entering the compressor and prevent the formation of oxides.

If the oil taken from the compressor and measured is found to be signicantly

lower than listed in the table above, clean the excess oil through use of suction

and liquid line lter driers. Beginning in Step 4, follow the same procedure as for burnout cleanup.

Use an acid test kit to check the oil for acid. If acid is found, beginning in

Step 4, follow procedures indicated for burnout cleanup.

Dispose of oil and compressor using an approved environmentally safe

disposal method.

□ Step 3. Mount the Replacement Compressor

Do not remove the dust cover or rubber shipping plugs until all other system

connections are complete (i.e. new liquid line lter drier(s) installed and all tubing

changes made - see Steps 4 and 5). The amount of time the compressor is open to the atmosphere must be kept to a minimum.

Use the new mounting grommets and sleeves that are shipped with the

compressor to mount it. The sleeves will prevent over compression of the grommets. Re-use the mounting bolts from the compressor that was removed. The mounting bolts will bottom out when tight.

FIGURE 5 - Identication of Compressors by Location

Compressor

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 12

Page 13

Compressor Staging for Cooling (applies to Models RCB, RDB, RDCB, RDDB RECB, REDB)

MAPSIII

Cabinet D

360 418 444 484

480 538 564 602

600 658 684 722

720 804 842

DH or E (RDB/RDDB/REDB 418) 5 DH or E (RDB/RDDB/REDB 444) 7 DH or E (RDB/RDDB/REDB 484) 10

DH or E (RDB/RDDB/REDB 538) 5 DH or E (RDB/RDDB/REDB 564) 7 DH or E (RDB/RDDB/REDB 602) 10

DH or E (RDB/RDDB/REDB 658) 5 DH or E (RDB/RDDB/REDB 684) 7 DH or E (RDB/RDDB/REDB 722) 10

DH or E (RDB/RDDB/REDB 804) 7 DH or E (RDB/RDDB/REDB 842) 10

Compressor Cooling Staging

Circuit Tonnage 1 2 3 4 5 6 7 8

A 10 C 5 D 15

A 10 C 15 D 15

A 10 B 10 C 15 D 15

A 15 B 15 C 15 D 15

C A A+C D C+D A+C+D

A D A+D C+D A+C+D

B D A+B A+D C+D A+B+D B+C+D A+B+C+D

B B+C B+C+D A+B+C+D

Compressor Model and P/N by Tonnage and Voltage

Compressor Model

ZP57K3E 5 216686 216686 216687 216688

ZP83KCE 7 216689 216689 216690 216691

ZP120KCE 10 216695 216695 216696 216697

ZP182KCE

Wiring Harness

Crankcase Heater P/N 216402 P/N 216404 P/N 216405

ARI Tonnage

15 216454 216454 216455 216456

One each for each compressor

208V 230V 460V 575V

P/N 223028 P/N 223029 P/N 223030

Compressor P/N

□ Step 4. Install New Filter Driers (Select procedure that applies.)

IF the oil measured in Step 2 was not signicantly less than the amount shown

in the table on page 12 or the test for acid in Step 2 did NOT indicate burnout ,

install a new R-410A refrigerant liquid line lter drier. The lter drier must be rated

for no less than 600 psig and be the proper size for the circuit. Because R-410A

refrigerant requires POE oil which absorbs moisture quickly, it is important to change the lter drier any time the circuit is opened.

It is recommended to use a tubing cutter when cutting out a lter drier as the

desiccant absorbs and holds moisture better when it is cool. Heat from a torch may

cause moisture to leave the lter and be absorbed in the oil. Be careful to keep dirt, lings, and other contaminants out of the system.

Continue to Step 5. IF the oil measured in Step 2 was signicantly less than shown in the table on

page 12 or the test for acid in Step 2 did indicate compressor burnout, do the following:

a) Install a liquid line lter drier. If there is acid, install an acid removing lter drier.

Size the acid-removing lter drier at least one capacity size larger than normally required for the circuit.

b) Install a temporary lter drier in the suction line. When there is acid, a 100%

activated alumina suction lter drier is recommended. The suction line drier should be sized properly for the circuit and have a service access tting to

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 13

Page 14

3.0 Maintenance/ Service Procedures (cont'd)

3.6 Compressor

Maintenance (cont'd)

□ Step 4. Install New Filter Driers (cont'd)

monitor pressure drop across the drier. (NOTE: Suction line lter drier must be removed after 72 hours of operation.)

Step 12 includes the remaining procedures required for cleanup of a burnout. Continue to Step 5.

□ Step 5. Braze on Suction and Discharge Lines

CAUTION; Do not leave system open to the atmosphere any

longer than minimum required for installation. POE oil in the compressors is extremely susceptible to moisture absorption. Always keep ends of tubing sealed during installation. See Hazard Levels, page 2.

Brazing materials must be able to withstand the high pressure of R-410A refrigerant. A high temperature, silver phosphate type brazing with 5% or greater alloy is recommended.

To prevent oxidation, purge tubing with 2-3 psig of regulated dry nitrogen while it is being brazed. Open the service valve as needed to release the nitrogen. Do not allow moisture to enter the system.

The installer is responsible for brazing and for complying with appropriate standard refrigerant piping procedures.

CAUTION: All brazing should be done using a 2 to 3 psig dry

nitrogen purge owing through the pipe being brazed. See Hazard

Levels, pg 2.

CAUTION: When brazing, protect all painted surfaces and

components from excessive heat. Wet wrap all valves but do not allow moisture to enter the tubing. See Hazard Levels, page 2.

□ Step 6. Check System for Leaks

After installation is complete, pressurize the circuit to approximately 75 psig using

nitrogen and a few ounces of refrigerant. Check for leaks using soap bubbles or other leak-detecting methods.

□ Step 7. Evacuate the Circuit

Evacuate one circuit at a time. Use a vacuum pump and micron gauge. Each

circuit must be evacuated to hold a 500 micron vacuum. Vacuum must be pulled on both the discharge (high) and suction (low) side. Do the suction side rst; and

the compressor discharge side second. To establish that a circuit is leak-free and moisture-free, a standing vacuum test is recommended. Close off the valve to the vacuum pump and observe the micron gauge. If the vacuum gauge does not rise above 500 microns in one minute, the evacuation should be complete. If the vacuum gauge does rise above 500 microns in one minute, evacuation is incomplete or the circuit has a leak. Repeat as needed until evacuation is complete. The evacuation process must be done on each circuit.

NOTE: Evacuation will not remove moisture from POE oil. Moisture must be

prevented from getting in the oil.

Continue and/or repeat Steps 6 and 7 until evacuation is complete.

CAUTION: Do not use the replacement compressor as an

evacuation assist and never apply voltage to a compressor while it is in a vacuum. See Hazard Levels, page 2.

Moisture and air are harmful to the system because they increase the condensing temperature, raise the discharge gas temperature, cause formation of acids, and cause oil breakdown.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 14

Page 15

CAUTION: Do not leave a circuit open to the atmosphere any

longer than minimum required for installation. POE oil in the compressor is extremely susceptible to moisture absorption. Evacuation will not remove moisture from POE oil.

□ Step 8. Check the Electrical System

After the system has been evacuated, reconnect the electrical plug to the compressor or the wires to the compressor terminals. It is a normal practice to replace all starting components any time a compressor is changed.

WARNING

Do not apply voltage to the compressor when the plug is removed or terminals disconnected.

Crankcase Heater - Connect the crankcase heater. The crankcase heater is ener-

gized continuously and is extremely important to proper compressor operation and long life.

The crankcase heater must be energized for at least 24 hours before starting the unit or after a power outage of more than 8 hours. Be sure to disable cooling controls

before turning on power to warm up crankcase heaters.

CAUTION: Crankcase heaters must be allowed to warm up for

at least 24 hours prior to startup. Disable cooling controls before turning on power to warm up crankcase heaters.

□ Step 9. Charge the System (Use R-410A refrigerant only.)

Refer to the table on page 16 for the approximate amount of refrigerant required

and follow the instructions below to charge the circuit. R-410A refrigerant MUST

BE charged as a LIQUID.

NOTE: Outdoor temperature must be between 70-95°F (21-35°C) for verifying superheat and subcooling. If temperature is not within this range, consult the factory service department before charging.

If equipped with an optional hot gas bypass valve, disable the hot gas bypass

valve before charging. The method of disabling the bypass valve depends on whether or not there is a shutoff valve in the line between the compressor discharge and the hot gas bypass valve.

If there is a shutoff valve in the line between the compressor discharge and the hot gas bypass valve, close the shutoff valve. When measurements are complete, open the valve.

If there is not a shutoff valve in the line between the compressor discharge and the hot gas bypass valve, disable the bypass by removing the cover from the bypass valve and adjusting the spring tension. Count and record the number of counterclockwise turns until the spring tension is relieved. (When ready to return the bypass valve to its original setting, turn the spring the same number of turns clockwise. To check setting, see instructions in Paragraph 3.9.5.)

IMPORTANT: Do not release refrigerant to the atmosphere! If required service procedures include the adding or removing

of refrigerant, the qualied HVAC service technician must

comply with all federal, state or provincial, and local laws.

Liquid charge the high side to 80%. With the system running, add the balance of

the charge to the correct superheat and subcooling values. Refer to Step 11, page 17, and the instructions in Paragraph 3.5, page 9.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 15

Page 16

3. Maintenance/ Service Procedures (cont'd)

3.6 Compressor

Maintenance (cont'd)

□ Step 9. Charge the

System (cont'd))

Approximate R410-A Refr

igerant Charge (lbs) by Model Size and

Compressor for Each Circuit (See FIGURE 5, page 12, to identify location.)

D Cabinet Models

and Size

RCB/RDCB/RECB 360 10.0 N/A 13.0 6.0 N/A

RCB/RDCB/RECB 480 10.0 13.0 13.0 N/A N/A

RCB/RDCB/RECB 600 10.0 10.0 13.0 13.0 N/A

RCB/RDCB/RECB 720 13.0 13.0 13.0 13.0 N/A

RDB/RDDB/REDB 418 10.0 N/A 13.0 6.0 9.0

RDB/RDDB/REDB 444 10.0 N/A 13.0 6.0 9.0

RDB/RDDB/REDB 484 10.0 N/A 13.0 6.0 11.0

RDB/RDDB/REDB 538 10.0 13.0 13.0 N/A 9.0

RDB/RDDB/REDB 564 10.0 13.0 13.0 N/A 9.0

RDB/RDDB/REDB 602 10.0 13.0 13.0 N/A 11.0

RDB/RDDB/REDB 658 10.0 10.0 13.0 13.0 9.0

RDB/RDDB/REDB 684 10.0 10.0 13.0 13.0 9.0

RDB/RDDB/REDB 722 10.0 10.0 13.0 13.0 11.0

RDB/RDDB/REDB 804 13.0 13.0 13.0 13.0 9.0

RDB/RDDB/REDB 842 13.0 13.0 13.0 13.0 11.0

A B C D E or DH

Compressor Circuit

□ Step 10. System Startup

Assure voltage to compressor does not drop below minimum allowable voltage

(e.g. 187 volts for 230/208-3-60, 415 volts for 460/3/60, 518 volts for 575/3/60) during the period the compressor is trying to start. If a low voltage or voltage

imbalance condition exists, the electrical problem must be determined and corrected prior to operating the unit.

Voltage Imbalance - Voltage imbalance is becoming a more common problem.

In a 3-phase system, excessive voltage imbalance between phases will cause motors to overheat and compressors to fail. Maximum allowable imbalance is

2%. To determine voltage imbalance, measure and record the voltage of all three

phases. Take the measurements at the compressor terminals with the compressor operating.

Voltage Imbalance Formula:

Key:

Formula:

If the imbalance is within the 2% tolerance, voltage imbalance is not a problem and the system may be operated. If the imbalance exceeds the 2% tolerance, follow

the procedures below.

Solutions to Voltage Imbalance:

The cause for a voltage imbalance problem can originate at the power company or can be caused inside the building. Try the following on-site solution to determine if the problem can be easily resolved.

Roll the connections at the compressor terminals one forward. Connect the wire now on Terminal 1 to Terminal 2, 2 to 3, and 3 to 1. Re-measure and re-calculate

the voltage imbalance. If the imbalance is within 2%, the system may be operated.

If the imbalance is not within tolerance, roll the connections one more forward. Re-measure and re-calculate the voltage imbalance. If the imbalance is within

2%, the system may be operated. If the voltage imbalance still exceeds 2%, do

not start the system. Contact the building owner or person responsible to have an electrician analyze the buildings's power supply and load distribution.

Power Supply Voltage Phasing - Connect refrigerant pressure gauges to the suction and discharge lines of the compressors and an electric meter to the power supply.

V1, V2, V3 = line voltages as measured

VA (Average )= (V1 + V2+ V3) / 3

VD = Line Voltage (V1, V2, or V3 that deviates farthest from average (VA)

% of Voltage Imbalance = [100 (VA - VD)] / VA

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 16

Page 17

CAUTION: Be sure to connect pressure gauges to the suction and discharge lines before system start-up so that compressor rotation can be checked immediately. Scroll compressors will be destroyed if allowed to operate in the wrong direction. See Hazard Levels, page 2.

Record the ambient temperature. Adjust the system controller so that a call for cooling exists.

NOTE: Outdoor ambient lockouts may prevent mechanical cooling. Temporarily override lockouts by lowering the cooling setpoint. When testing is complete, reset the controller.

Because it is possible to unknowingly connect 3-phase power in such a way as to cause the scroll compressor or blower to rotate in reverse, it is very important to check this on startup.

Check Compressors - Immediately at startup, observe the gauges. If the suction pressure rises and discharge pressure drops, the compressor is operating in reverse and must be shut down. Turn off the power and switch the 3-phase line voltage wiring connections before restarting the unit.

(Important NOTE: If allowed to operate for several minutes in reverse, the compressor’s internal protector will trip. If a compressor is repeatedly allowed to restart and run in reverse, the compressor will be permanently damaged.)

□ Step 11. Check Subcooling and Superheat

Superheat is the verication that the evaporator coil is properly using the

refrigerant supplied. Too much superheat indicates that the coil is undercharged.

Too little superheat indicates that the coil is overcharged and potentially ooding liquid refrigerant to the compressor.

Subcooling is the measurement of liquid refrigerant stored in the condenser

coil. Too much subcooling indicates a system overcharge. Too little subcooling indicates a system undercharge and may not provide the thermal expansion valve

with a full column of liquid refrigerant for proper operation.

Two important requirements before checking superheat and subcooling:

1) This unit has fully intertwined refrigerant circuits and each circuit MUST be

isolated before measuring its temperature. Another active circuit will inuence the

reading and make it impossible to determine accurate superheat and subcooling.

2) If equipped with an optional hot gas bypass, disable the hot gas bypass valve

before charging. The method of disabling the bypass valve depends on whether or not there is a shutoff valve in the line between the compressor discharge and the hot gas bypass valve.

If there is a shutoff valve in the line between the compressor discharge and the hot gas bypass valve, close the shutoff valve. When measurements are complete, open the valve.

IMPORTANT: Do not release refrigerant to the atmosphere! If required service procedures include the adding or removing

of refrigerant, the qualied HVAC service technician must

comply with all federal, state or provincial, and local laws.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 17

Page 18

3. Maintenance/ Service Procedures (cont'd)

3.6 Compressor

Maintenance (cont'd)

□ Step 11. Check Subcooling and Superheat. (cont'd)

Follow the procedures in Paragraph 3.5 to check subcooling and superheat.

□ Step 12. (Select the procedure that applies.)

IF the oil measured in Step 2 was signicantly less than in the table on

page 12 or the acid test in Step 2 indicated a burnout, do the following:

a) Operate the unit for several hours. Check the pressure drop through the

temporary suction line lter drier. If the pressure drop exceeds 8 psig, recover the refrigerant, replace the suction line lter drier with the same type as removed, replace the liquid line lter drier, evacuate the circuit, and re-charge

with the recovered refrigerant.

Continue to monitor the pressure drop through the suction line lter drier and

repeat the process above until the pressure does not exceed 8 psig after several hours of operation. (NOTE: System must be allowed to run no more

than 72 hours with a suction line lter drier.)

b) Allow the system to operate for 4-8 hours. Recover the refrigerant and take an

oil sample. Retest the oil for acid.

c) If the test for acid is negative, remove the suction line lter drier, replace

the liquid line drier, evacuate, and re-charge the system with the recovered

refrigerant. If the test indicates acid, replace both the liquid line lter drier and the suction

line lter drier and repeat b) and c).

CAUTION: After cleanup is complete, remove the suction line

lter drier. See Hazard Levels, page 2.

3.7 Thermostatic

Expansion Valves

d) Verify subcooling and superheat (refer to Step 11). e) When the system is operating properly, remove the gauges.

IF the oil measured in Step 2 was not signicantly less than that shown in the table on page 12 or the acid test in Step 2 did not indicate a compressor burnout, continue to the review in Step 13.

□ Step 13 . Review ALL Steps to ensure that nothing was

overlooked.

All refrigeration circuits have a thermostatic expansion valve. Thermostatic expansion

valves (TXV's) do not have replaceable parts. If a replacement valve is required, it

must be an R410-A valve and be sized correctly for the application. All refrigerant ser-

vice should be performed by a technician qualied in R410-A refrigerant.

Replacement valves by size and circuit are listed in the following table.

Model & Size Compressor Circuit P/N Sporlan No. Connection Sizes

A 220556 BBIZE-8-GA 5/8x7/8x1/4

RCB/RDCB/RECB

360

RDB/RDDB/REDB

418/444/484

RCB/RDCB/RECB

480

RDB/RDDB/REDB

538/564/602

E or DH (RDB/RDDB/REDB 418 only) 234987 BBIZE-4-GA 1/2x7/8x1/4

E or DH (RDB/RDDB/REDB 444 only) 220555 BBIZE-6-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 484 only) 220556 BBIZE-8-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 538 only) 234987 BBIZE-4-GA 1/2x7/8x1/4

E or DH (RDB/RDDB/REDB 564 only) 220555 BBIZE-6-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 602 only) 220556 BBIZE-8-GA 5/8x7/8x1/4

C 234987 BBIZE-4-GA 1/2x7/8x1/4

D 220558 BBIZE-15-GA 7/8x1-1/8x1/4

A 220556 BBIZE-8-GA 5/8x7/8x1/4

C 220558 BBIZE-15-GA 7/8x1-1/8x1/4

D 220558 BBIZE-15-GA 7/8x1-1/8x1/4

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 18

Page 19

Model & Size Compressor Circuit P/N Sporlan No. Connection Sizes

A 220556 BBIZE-8-GA 5/8x7/8x1/4

B 220556 BBIZE-8-GA 5/8x7/8x1/4

RCB/RDCB/RECB

600

RDB/RDDB/REDB

658/684/722

RCB/RDCB/RECB

720

RDB/RDDB/REDB

804/842

E or DH (RDB/RDDB/REDB 658 only) 234987 BBIZE-4-GA 1/2x7/8x1/4

E or DH (RDB/RDDB/REDB 684 only) 220555 BBIZE-6-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 722 only) 220556 BBIZE-8-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 804 only) 220555 BBIZE-6-GA 5/8x7/8x1/4

E or DH (RDB/RDDB/REDB 842 only) 220556 BBIZE-8-GA 5/8x7/8x1/4

C 220558 BBIZE-15-GA 7/8x1-1/8x1/4

D 220558 BBIZE-15-GA 7/8x1-1/8x1/4

A 220558 BBIZE-15-GA 7/8x1-1/8x1/4

B 220558 BBIZE-15-GA 7/8x1-1/8x1/4

C 220558 BBIZE-15-GA 7/8x1-1/8x1/4

D 220558 BBIZE-15-GA 7/8x1-1/8x1/4

3.8 Dampers and Damper Controls

Damper Motor

Service: Other than external cleaning, there is no service required on the dampers or

the damper motor. If the damper, control, or motor need to be replaced, replace with a factory-authorized replacement. For additional information on damper controls (Options GF 1-9), see the system installation manual Form I-MAPSIII Cabinet D.

Inlet Air Dampers

Location: Dampers and damper motors are located in the inlet air opening. Function: Dampers operate in response to the control selected. Damper controls are

shown below.

Service: Clean dampers and controls of dust and dirt.

2-Position Damper Motor (Option AR8)

Function: The 2-position damper motor opens and closes the dampers in response to

unit operation or a eld-supplied time clock.

Motor closes dampers on heater shutdown.

Modulating Motor (Option AR25)

Function: The modulating damper motor actuates the dampers in response to I/Q

control with actuation from input switch settings, a remote potentiometer, building pressure, CO2, 2-position outside air enthalpy, or dual reference enthalpy. Motor closes dampers on heater shutdown.

3.9 Other Controls

NOTE: Refer to Control Instruction Form CP-MAPSIII D15/D16 for information on the programmable controller.

Other factory-installed standard and optional controls are illustrated below. Find their location in FIGURE 1, page 4. Cleaning external dirt is the only service procedure. If any need to be replaced, use only factory-authorized replacement parts.

3.9.1 Programmable Digital Controller and Sensors

Display

I/Q System Controller

All MAPSIII systems have a unit-mounted,

24-volt programmable I/Q controller.

Depending on how it was ordered, the system

is equipped for either neutral air/discharge air

control (Option D15) or space control with discharge air reset (Option D16). The controller is factory programmed to match the selection. See the control instruction manual for more information.

Some sensors are standard and others will depend on option selection.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 19

Page 20

Outside

Air

Return

Air

Mixed Air Averaging Sensor (between filters and coil)

Return Air

Sensor

Temperature/

Humidity

Outside

Air Sensor

Temperature/

Humidity

Filters

Dirty Filter Switch Sensor

(entering air side)

Dirty Filter Switch Sensor (leaving air side)

Coils

Air Proving Switch Tap

Heat

Section

Discharge Temperature Sensor (field installed)

Vertical

Discharge

Horizontal

Discharge

Condenser Section

3.0 Maintenance Procedures (cont'd)

3.9 Other Controls (cont'd)

3.9.1 Programmable Digital Controller and Sensors (cont'd)

FIGURE 6 - Airow and Sensor Locations

Service: If a sensor needs to be replaced, use only a factory authorized replacement

part designed for the purpose. Refer to the digital wiring requirements in Paragraph 7.4 of Installation Form I-MAPSIII&IV).

If a controller needs to be replaced, it must be replaced with the same controller and software.

3.9.2 Air Proving Switch

3.9.3 Motor Starter (Option AN10) or Variable Frequency Drive (Option VFD1 or VFD2)

3.9.4 Voltage Protection, Option PL4

3.9.5 Hot Gas Bypass

Valve, Option AUC9

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 20

Bypass valve

Function: The airow proving switch is a pressure switch that veri-

es to the main controller that the blower (plenum fan) is operating.

Service: If the switch needs to be replaced, use a factory-authorized replacement designed for the application.

Function: When the main controller calls for blower operation, either an IEC type

starter with a contactor or a variable frequency drive module responds to operate the

motor.

The starter is in the high voltage control compartment. The variable frequency drive was eld installed in a location that is no more than 50 feet (15M) away where the minimum temperature is 18°F (-9°C). Control of the variable frequency drive module is

coordinated with the main controller, and depending on what was ordered, can function in response to temperature, CO2, or pressure controls.

Service: If a starter or contactor need replaced, use only the identical replacement that is designed to match the motor and voltage of the system.

If a VFD needs to be replaced, contact the factory service department. Be prepared to

provide the model, serial, and wiring diagram numbers.

Function: Phase loss and low or high voltage can cause damage to electrical components. This safety control monitors phase loss and voltage and shuts down the unit when its limits are exceeded. The device is auto reset and allows the unit to restart when the power conditions are corrected.

Function: The hot gas bypass valve allows some of the refrigerant gas from the suction line to be re-routed directly to the evaporator coil providing for expanded compressor modulation at low outside air temperatures.

Service: To check the hot gas bypass valve setting, connect a pressure gauge to the suction line and block the entering air to the evaporator coil. Suction pressure will drop, and the hot gas bypass valve should begin to open at a approximately 115 psi and will be fully open at 95 psi. When the valve begins to open it will be hot to the touch (see caution below).

Page 21

CAUTION: Touching the operating hot gas bypass valve can cause a burn. Use caution when checking and adjusting the valve. See Hazard Levels, page 2.

If a hot gas bypass valve needs to be replaced, use only a factory-authorized replace-

ment for R410-A refrigerant. All refrigerant service should be done by a qualied

R410-A service technician.

3.9.6 Modulating

Reheat, Option AUR1

4.0 Gas Heat Section Maintenance Models RDCB and RDDB

Function: Units with modulating reheat control (Option AUR1) have a temperature

control board with a potentiometer, an air temperature sensor, and an electric discharge bypass valve. When reheat is active, the sensor monitors the air temperature as it leaves the reheat coil. Based on the potentiometer setpoint, the board will open or close the bypass valve. If the leaving air temperature is higher than the setpoint, the

board will open the valve adding refrigerant hot gas to the refrigerant liquid before it

enters the pre-cool coil. This reduces the coil's ability to absorb the heat, and thus, the reheat coil's ability to reject. If the leaving air temperature is lower than the setpoint, the opposite occurs.

Service: Check the wiring connections at the board. The board is polarity sensitive;

positive connects to terminal 1 and negative to terminal 2. The valve may be tested by measuring the resistance of the leads. Remove the power

and the leads from the board before testing. Resistance between the black and white leads should be about 75 Ohms. Resistance between the green and red leads should

be within 5% of the white and black.

Use only factory-authorized replacement parts.

This gas heater will operate with a minimum of maintenance. To ensure long life and satisfactory performance, a heater that is operated under normal conditions should be inspected and cleaned at the start of each heating season. If the heater is operating in an area where an unusual amount of dust or soot or other impurities are present in the

air, more frequent maintenance is recommended.

When any service is completed, be careful to reassemble correctly to ensure that no unsafe conditions are created. When re-lighting, always follow the lighting instructions on the furnace.

4.1 Heat Exchanger,

Burner, and Venter Maintenance

WARNING

Turn off the power before performing maintenance procedures. Lock disconnect switch in OFF position. When you turn off the power supply, turn off the gas at the external manual valve. See Hazard Levels, page 2.

This gas heat section is equipped with a TCORE

Inspect the gas heat section annually to determine if cleaning is necessary. If there is an accumulation of dirt, dust, and/or lint, clean the compartment.

style heat exchanger and burner.

CAUTION: Use of eye protection is recommended.

4.1.1 Instructions for Inspecting/Cleaning a Heat Exchanger

1. Shut off the gas supply.

2. Turn off electric power supply.

3. Open the gas heat section access door and the blower section door.

4. Remove the venter motor and wheel assembly. (See FIGURES 7 and 8.)

a) At the control board, locate the two or three venter motor wires. Mark and

disconnect the wires.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 21

Page 22

View BEFORE Removing

Venter Assembly and

Heat Exchanger Access Panel

Venter Assembly

Heat Exchanger

Access Panel

View AFTER Removing

Venter Assembly

and Heat Exchanger

Access Panel

NOTE: Some panels have been removed for illustration clarity.

Gas Train and Burner -

See Paragraph 4.1.2 to

remove slide-out burner.

4.0 Gas Heat Section Maintenance (cont'd)

4.1 Heat Exchanger, Burner, & Venter Maintenance (cont'd)

FIGURE 7 - View of the Heat Section showing Access to the

Heat Exchanger by Removing the Venter Assembly and the

Heat Exchanger Access Panel

FIGURE 8 - Remove the Venter Assembly before Removing the Heat Exchanger Access Panel

NOTE: To clean the

venter assembly while it is removed, follow the instructions in Paragraph

4.1.3.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 22

Lift venter

assembly out of the

housing.

Remove the perimeter sheetmetal

screws that secure the motor mount-

ing plate to the venter housing.

b) Locate the screws shown in FIGURE 8. Remove the screws and carefully lift

the venter wheel out of the housing. Remove the whole motor and wheel assembly including the large mounting plate.

NOTE: To clean the venter assembly or replace parts, follow the instructions in

Paragraph 4.1.3.

5. With the venter motor and wheel assembly removed, the large heat exchanger access panel is now removable (See FIGURE 7). Disconnect the limit switch wires. Remove the screws securing the heat exchanger access panel and remove the panel.

6. The outside of the heat exchanger is now in view here and through the blower door. Remove any external dirt or dust accumulation. Use a 60" inspection mirror to view the heat exchanger sections. Check the heat exchanger for cracks or holes. If a crack or hole is observed, replace the heat exchanger.

Page 23

With the burner removed in Paragraph 4.1.2, shine a light into each heat

exchanger section. With the light shining into the heat exchanger, observe the outside for visible light. Repeat this procedure with each heat exchanger section. If any light is observed, replace the heat exchanger.

If it is determined that the heat exchanger needs to be replaced, contact your

distributor or representative for replacement information.

4.1.2 Instructions for Inspecting / Cleaning the Burner

NOTE: With the burner

removed, it is possible to check the bottom of the heat exchanger. See Paragraph 4.1.1

FIGURE 9 - Remove the Burner/Venturi Assembly

The burner will slide out of the unit. Refer to FIGURE 9 and follow the instructions below to remove and inspect the burner

1. Disconnect the gas train at the two unions showing in FIGURE 9. Do not allow the portion of the gas train attached to the venturi tube to rotate. Slide the "free" section of gas train that includes the valves to the left out of the path of the slide-out burner. Do not disconnect the valve wires.

2. Loosen the screw holding the burner end shield. Remove the burner end shield

with the screw attached.

3. The burner is designed to slide out of the heater for inspection and/or service. Remove the screws above and below holding the burner assembly. Carefully pull the burner assembly (with pipe nipple attached) partially out of the cabinet. To completely remove the burner, mark and disconnect the sensor wires and the igniter and igniter board wires, and slide the burner out.

4. With the burner assembly removed, shine a ashlight on the burner ribbons. Look for carbon buildup, scale, dust, lint, and/or anything that might restrict ow through

the spaces between the burner ribbons. Holding the burner assembly so that any foreign material will fall away from the burner, use a stiff bristle brush to loosen and remove any foreign material(s). If the burner is excessively dirty, remove both

Direct View of the Burner after the Gas Train has been disconnected.

Burner End

Shield

Venturi/Burner Asembly

Break the gas train at the union before and the union after the controls. Be careful not to rotate the portion of the gas train connected to the venturi/ burner. Slide disconnected “valve section” of the gas train to the left so that it will be out of the path of the slide-out burner.

Venturi

Orifice

Loosen screw to remove burner end shield.

Burner

DSI Module

Flame Sensor

Burner/Venturi Assembly

Ignitor Assy

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 23

Page 24





4.0 Gas Heat

1/2” (13mm) from

motor plate to wheel

NOTE: Measure from

plate and not

the gasket.

Venter

Motor

Motor Plate with Gasket

Venter Wheel

Section Maintenance (cont'd)

4.1 Heat Exchanger, Burner, & Venter Maintenance (cont'd)

4.1.2 Instructions for Inspecting/Cleaning the Burner (cont'd)

of the burner end caps. Remove the screws that hold the end caps to the burner

housing. Lightly tap end caps to remove.

Clean all foreign material from the burner and venturi. After the burner is

thoroughly cleaned, replace the end caps making certain that they are tight against the burner housing. NOTE: If any of the burner components are damaged or deteriorated, replace the burner assembly.

Ignitor

CAUTION: Due to high voltage on the spark wire and electrode, do not touch when energized.

4.1.3 Maintenance Instructions for the Venter Motor and Wheel

Check the Ignitor and Flame Sensor

Ignitor - Locate the ignitor. Disconnect the wire; remove the screw and the ignitor.

Clean the ignitor assembly with an emery cloth. Spark gap must be maintained to 1/8". See FIGURE 10.

IMPORTANT: When re-assembling, the brown ground wire must remain attached to the ignitor.

Flame Sensor - Locate the ame sensor on the burner. Disconnect the wires; remove the screws and the ame

sensor. Clean with an emery cloth.

Flame Sensors

FIGURE 10 - Ignitor showing required Spark Gap Measurement

If the venter assembly is not already removed, remove it by following STEPS 1-4 in Paragraph 4.1.1 for accessing the heat exchanger (NOTE: It is not necessary to open the blower door.)

Note that during normal operation of the AG70 deep modulation control system, the current draw of the venter motor can exceed the full load amp rating on its nameplate. This condition is common when employing electronic wave-chopping technology to reduce the running speed of a single-phase type PSC alternating current motor. The technology reduces energy to the main winding by momentarily interrupting current for a variable amount of time, resulting in a reduction of the motor speed. The increased current is a result of increased slip, which is the difference between the rotation speeds

of the rotor and stator elds. All motors used in MAPS III systems are custom designed and built for this unique modulating application and cannot be replaced with a non-

approved motor. All prototype motors have been thoroughly tested with regards to temperature of the windings and bearings at all operating points and ambient conditions and approved by the manufacturer to assure the elevated current does not affect the normal motor life expectancy.

Remove dirt and grease from the venter housing, the motor casing, and the venter

wheel. Venter motor bearings are permanently lubricated.

If replacing venter parts, see FIGURE 11 for proper spacing. If the motor plate gasket is damaged or deteriorated, replace it with P/N 222856.

FIGURE 11 - Venter Wheel Position on Shaft

NOTE: Manufacturer recommends

replacing venter motor capacitor See FIGURE 12.) when replacing venter motor. Use only factory-authorized replacement parts.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 24

Page 25

4.1.4 Re-Assemble the Heat Exchanger Panel, Burner, Gas Train, and Venter

Instructions to Re-Assemble the Gas Heat Section (Refer back to FIGURES 7, 8, and 9.)

1. Re-attach the Heat Exchanger Panel - Re-attach the access panel being sure to use all of the screws. See FIGURE 7. Reconnect the limit switch wire.

2. Re-attach the venter assembly using all of the screws removed. See FIGURE 8.

Re-connect the venter wires at the board. If installing a replacement motor, check the wiring diagram for connections.

3. Re-install the Burner and Manifold

a) Slide the entire venturi/burner assembly into position. b) Re-connect the ignitor and sensor wires. Verify that the wires and the

connections are good

c) Insert all of the screws along the top and the bottom. Re-attach the burner end

shield.

d) Re-connect the gas train. Be careful not to rotate the section attached to

the venturi/burner. Check the burner orice to be sure that it is secure and

positioned properly.

4. Check the wiring and sensing tube connections. Turn on the electric and the

gas. Leak test the connections with a leak detecting solution. Check for proper

operation.

4.2.1 General

FIGURE 12 - Gas Heat Section Controls in a MAPSIII "D" Cabinet

The heat section controls

are located on the oor of the heat section; .see

FIGURE 1, page 4.)

NOTE: Conguration of

heat sections in relation to the blower depends on date of manufacture. Currently manufactured systems with two heat sections have the non-modulating furnace closest to the blower and the modulating furnace downstream. Previously manufactured systems may have the opposite

conguration.

IMPORTANT NOTE: The information in Section 4.2 applies to standard natural gas MAPSIII D Cabinet Models RDCB and RDDB manufactured beginning 12/2011. A Model RDCB or RDDB manufactured prior to 12/2011 may also have these gas control components. The identication of the ignition board in the Serial No. on the heat section rating plate will determine whether this information applies. If the ignition code in the serial number is 96, the information in Section 4.2 applies. If the ignition code is 90, 91, 92, or 93, contact your representative or distributor or search RezSpec.com for a previous version of this manual.

Serial No. Sample: 3 BKH 789 BK 08 N 96 7D

Also, if the unit is propane ("N" in the Serial No. is an "L"), modulation control information here does not apply. Refer to the rating plate or contact your distributor for information.

Thermal Circuit

Breaker

Fuse Holder

Pressure Switch

(Combustion Air)

Pressure

Gas Heat Section

PAM Relay

Switch

(Airflow)

Electrical Box Applies to All Sizes (furnace with modulating burner)

Gas Heat Section Electrical Box Applies only to Sizes 1000, 1200, 1400, 1600 with two furnace sections (Non-modulating heat section is closest to the blower.)

Pressure Switch

(Combustion Air)

Ignition Board (See FIGURE 14.)

Venter Motor Capacitor Bracket

Transformer 30VA Terminal Blocks

Modulating Ignition Board with ID Plug (See FIGURE 13A.)

Terminal Blocks

Transformer 75VA

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 25

Page 26

4. Gas Heat Section Maintenance (cont'd)

4.2 Gas Heat Section Controls

4.2.2 Ignition System (Natural Gas only)

The modulating furnace has the control module in the control compartment (FIGURES 12 and 13A) with an additional board (FIGURE 13B) attached directly to the side of

the burner to control spark. Do not attempt to disassemble either board. However, each heating season check the lead wires for insulation deterioration and good connections.

If replacement is required, these boards must be replaced with identical parts.

FIGURE 13A - Ignition Control Module (Deep Modulation Board)

IMPORTANT: The control module illustrated is P/N 257246 used on all MAPSIII Cabinet D heat sections manufactured beginning

8/2011 and on previously manufactured units as a special. The ID plug on each

board is unique for each size of heat section. A replacement board will require either a

new ID plug or reuse of the ID plug from the board being replaced.

Standard MAPSIII Cabinet D heat sections

manufactured prior to 8/2011 have a unique

ignition board by size and do not have a replaceable ID plug.

The control has a built-in, self-diagnostic capability. The control continuously monitors its own operation and the operation of the heat section including direct spark ignition, safety and modulating valves, and venter motor speed. The 3-digit display on the control indicates the current system state, warnings, failures, and test modes.

NOTE: Operating and

Lockout Error Codes

displayed on ignition controller 3-character display (FIGURE 13A) are listed in Troubleshooting Paragraph 7.3.3.

Display Info (example only) Description D CAb Furnace series or model name, for example, "D cabinet

500 Heat Section Size nAt Fuel type

1.01 Software version

LED Display Heat Mode Description

FIGURE 13B - Spark Ignition (DSI) Board, P/N 257975

CAUTION: Due to high voltage on the spark wire and electrode, do not touch when energized. See Hazard Levels, page 2.

3-Character Display

Controller LED Information (displayed on power up)

series"

Normal Furnace Operation (LED 3-Character Display in FIGURE 13A)

OFF Mode (OFF) System Idle - Control board has power, no faults found, no call for heat.

PURGE Mode (Pur)

IGNITION Mode (Ign)

WARM-UP Mode (HEA)

RUN Mode (run) Normal modulating operation.

Ignition Retry (rEt)

System is purging the heat exchanger – No gas on, no ame, inducer runs for the specied purge timings. Purge cycles occur immediately before and after

each burner operation. System is initiating burner operation – Igniter energized, modulating valve moved to ignition setting, gas on. Maintained for the trial-for-ignition period

and the ve second ame stabilization period.

Period between Ignition and Run – System checks completed before modulation control begins.

System has had a failed ignition attempt or has lost ame during burner

operation and is beginning another ignition cycle.

Spark Board is attached to the side of the burner.

ID Plug

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 26

Page 27

Modulating Gas Control Sequence of Operation (single heat

section sizes and the heat section furthest from the blower on dual heat section sizes

- natural gas only)

1) Call for Heat - The IQ controller calls for heat (there is a closure between "R" and "W" and at least 2 VDC to the analog input). The ignition system circuit board will check

the modulating valve position and move to lightoff position. It checks to see that the limit switch is closed and the pressure switch is open. If the pressure switch is closed, the circuit board will wait indenitely for the switch to open. If the switch is open, the circuit board proceeds to prepurge.

2) Prepurge - After the actuator moves to its lightoff position, the circuit board energizes the venter motor and waits for the pressure switch to close. If the pressure switch does not close at the beginning of a heat cycle, the venter motor will run for two min-

utes, then cycle off for 30 seconds, then on for two minutes, and so forth indenitely.

When the pressure switch is proven closed, the venter motor ramps up to the appropri-

ate lightoff speed and the circuit board begins the prepurge time. If ame is present any time while in prepurge, the prepurge time is restarted. If ame is present long enough to

cause lockout, refer to the Troubleshooting Guide in Paragraph 6.2.2. The ignition system circuit board runs the venter motor for a 30-second prepurge time, then proceeds to the ignition trial period.

3) Ignition Trial Period - The ignition system circuit board energizes the spark and

main gas valve. The venter remains energized. If ame is sensed during the rst 6 seconds, the spark is de-energized. If ame has not been sensed during the rst 6

seconds, the control de-energizes the spark output and keeps the gas valve energized

for an additional one second ame proving period. If ame is not present after the ame

proving period, the control de-energizes the gas valve and proceeds with three ignition

re-tries as specied in “Abnormal Heat Cycle, Ignition Retry”. If ame is present, the

circuit board proceeds to steady heat. After three re-tries, the board will lockout for one

hour. It will require a cycling of power to reset before the one-hour limit.

4) Modulating Heat - As long as the call for heat exists, the circuit board not only modulates the gas to precisely meet varying load conditions, but also modulates the

combustion air to maintain stable performance and optimize thermal efciency across

the entire modulating range. Circuit board inputs are continuously monitored to ensure

limit switch is closed and ame is established. When the call for heat is removed, the

ignition system circuit board de-energizes the gas valve and begins postpurge timing.

5) Post Purge - The venter motor output remains on for a 45 second postpurge period

after the system controller is satised.

Ignition Controller on Non-Modulating Gas-Fired Furnace on MAPS D Sizes 1000, 1200,

1400, or 1600 with Two Furnaces

FIGURE 14 - DSI Integrated Control Module (Ignition Board) used on Non-Modulating Heat Section

DSI Integrated Control Module (ignition system circuit board) - See FIGURE 14.

The module is located in the control compartment and monitors the operation of the gas heater including ignition. The green and yellow LED indicator lights ash to indicate normal and abnormal conditions. If the heater fails to operate properly, check these signals to determine the cause and/or to eliminate certain causes. The only replaceable component is the 3 amp Type ATC or ATO fuse. If the fuse is blown, the problem is most likely an external overload. Correct the problem and replace the fuse

(eld supplied or P/N 201685).

Control Status - Green LED Codes

Steady ON ...... Normal Operation, No call for heat

Fast Flash ....... Normal Operation, Call for heat

1 Flash ............ System Lockout, Failed to detect or sustain ame

2 Flashes ........ Pressure Switch Did Not Close within 30 Seconds

of Venter Motor

3 Flashes ........ High Limit or Flame Rollout Switch Open

4 Flashes ........ Pressure Switch is Closed Before Venter Motor is

Energized

Steady OFF .... Blown fuse, No Power, or Defective Board

Flame Status - Yellow LED Codes

Steady ON ...... Flame is sensed

Slow Flash ...... Weak ame (current below 1.0 microamps ± 50%)

Fast Flash ....... Undesired Flame (valve open and no call for heat)

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 27

Page 28

4. Gas Heat Section Maintenance (cont'd)

4.2 Heat Section

Controls (cont'd)

4.2.2 Ignition System

(cont'd)

Ignition Controller on Non-Modulating Gas-Fired Furnace on MAPS D Sizes 1000, 1200, 1400, or 1600 with Two Furnaces (cont'd)

Do not attempt to disassemble the control module. However, each heating season check the lead wires for insulation deterioration and good connections.

Proper operation of the direct spark ignition system requires a minimum ame signal of

1.0 microamps as measured by a microampmeter.

Normal Heat Cycle Operating Sequence - Non-Modulating Furnace of D Cabinet with Size 1000, 1200, 1400, or 1600 Heat Section

1) Call for Heat - The heating/cooling system controller calls for heat. The ignition system circuit board checks to see that the limit switch is closed and the pressure switch is

open. If the limit switch is open, the circuit board responds as dened in the “Abnormal Heat Cycle, Limit Switch Operation”. If the pressure switch is closed, the circuit board will do four ashes on the green LED and wait indenitely for the pressure switch to

open. If the pressure switch is open, the circuit board proceeds to prepurge.

2) Prepurge - The circuit board energizes the venter motor and waits for the pressure switch to close. If the pressure switch does not close within 30 seconds of the venter

motor energizing, the circuit board will do two ashes on the green LED. The circuit board will leave the venter motor energized indenitely as long as the call for heat

remains and the pressure switch is open. When the pressure switch is proven closed, the circuit board begins the prepurge time.

If ame is present any time while in prepurge, the prepurge time is restarted. If ame is present long enough to cause lockout, the circuit board responds as dened in “Fault Modes, Undesired Flame”.

The ignition system circuit board runs the venter motor for a 20 second prepurge time, then proceeds to the ignition trial period.

3) Ignition Trial Period - The ignition system circuit board energizes the spark and

main gas valve. The venter remains energized. If ame is sensed at the burner during the rst 16 seconds, the spark is de-energized. If ame has not been sensed during the rst 16 seconds, the control de-energizes the spark output and keeps the gas valve energized for an additional one second ame proving period. If ame is not present after the ame proving period, the control de-energizes the gas valve and proceeds with ignition re-tries as specied in “Abnormal Heat Cycle, Ignition Retry”. If ame is

present, the circuit board proceeds to steady heat.

4) Steady Heat - Circuit board inputs are continuously monitored to ensure limit and

pressure switches are closed, ame is established, and the system controller call for

heat remains. When the call for heat is removed, the ignition system circuit board deenergizes the gas valve and begins postpurge timing.

5) Post Purge - The venter motor output remains on for a 45 second postpurge period

after the system controller is satised.

Abnormal Heat Cycle

Functions - Non-

Modulating Furnace of D Cabinet with Size 1000, 1200, 1400, or 1600 Heat Section

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 28

Interrupted Call for Heat - If the system controller call for heat is removed before the

ame is recognized, the circuit board will run the venter motor for the post purge period

and de-energize all outputs. If the call for heat is removed after successful ignition, the circuit board will de-energize the gas valve and run the venter motor through post purge.

Ignition Retry - If ame is not established on the 1st trial for ignition period, the igni- tion system circuit board de-energizes the gas valve, and the venter motor remains energized for an inter-purge period of 10 seconds. The spark and gas valve are then re-energized, and the circuit board initiates a 2nd trial for ignition.

If ame is not established on the 2nd trial for ignition, the circuit board de-energizes

the gas valve and venter motor remains energized. The spark and gas valve are reenergized and the circuit board initiates a 3rd trial for ignition. If ame is not established on the 3rd trial for ignition period, the circuit board de-energizes the gas valve, and the venter motor remains energized for an inter-purge period of 10 seconds. The circuit board then re-energizes the gas valve and spark and initiates a 4th trial for ignition.

Page 29

Ignition System Fault Modes - Non-

Modulating Furnace of D Cabinet with Size 1000, 1200, 1400, or 1600 Heat Section

If ame is not established on the 4th trial for ignition (initial try plus 3 re-tries), the circuit

board de-energizes the gas valve and goes into lockout. The circuit board goes to one

ash on the green LED to indicate ignition failure lockout.

Limit Switch Operation - The limit switch is ignored unless a call for heat is present (W energized). If the limit switch is open and a call for heat is present, the control deenergizes the gas valve and runs the blower motor on heat speed and runs the venter

motor. The control will be in soft lockout and ashing fault code "3" before returning to

normal operation. When the switch re-closes or the call for heat is lost, the control runs the venter motor through post purge and the blower through the selected fan off delay.

Pressure Switch - If the pressure switch opens before the trial for ignition period, the venter motor will run through the pressure switch recognition delay (2 seconds), the gas valve will be de-energized, and the venter motor will run through the postpurge time. The ignition system circuit board will re-start the heat cycle at the pressure switch proving state if the call for heat still exists. Pressure switch opening for less than 2 seconds during the trial for ignition period shall not interrupt the heat cycle. (Gas valve will de-energize while the pressure switch is open.) If the pressure switch opens after a successful ignition, the circuit board will de-ener-

gize the gas valve. If ame is lost before the end of the 2 second pressure switch recognition delay, the circuit board will respond to the loss of ame. If the pressure switch remains open for 2 seconds and the ame remains, the circuit board de-energizes the

gas valve and the venter motor runs through postpurge

Undesired Flame - If ame is sensed longer than 20 seconds while the gas valve is de-energized, the circuit board shall energize the venter motor. When ame is no

longer sensed, the venter motor will run through postpurge. The circuit board will do

a soft lockout, but will still respond to open limit and ame. The FLAME (yellow) LED ashes rapidly.

Gas Valve Relay Fault - If the circuit board senses the gas valve as energized for more than one second when the circuit board is not attempting to energize the gas valve, or the gas valve is sensed as not energized when it is supposed to be energized,

then the circuit board will lockout with the green LED off. The control assumes either

the contacts of the relay driving the gas valve have welded shut, or the sensing circuit

has failed. The venter motor is forced off to open the pressure switch to stop gas ow unless ame is present.

If the gas valve was sensed as closed when it should be open, and has not de-energized after the venter motor was shutoff for 15 seconds, then the venter motor is reenergized to vent the unburned gas.

Soft Lockout - The circuit board shall not initiate a call for heat while in lockout. The

circuit board will still respond to an open limit and undesired ame. Lockout shall automatically reset after one hour. Lockout may be manually reset by removing power from

the circuit board for more than one second or removing the call for heat for more than one and less than 20 seconds.

Hard Lockout - If the circuit board detects a fault on the board, the status LED will

be de-energized, and the circuit board will lockout as long as the fault remains. A hard lockout will automatically reset if the hardware fault clears.

Power Interruption - During a momentary power interruption or at voltage levels below the minimum operating voltage (line voltage or low voltage) the ignition system will self-recover without lockout when voltage returns to the operating range.

Power interruptions of less than 80mS shall not cause the circuit board to change operating states. Power interruptions greater than 80mS may cause the circuit board to interrupt the current operating cycle and re-start.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 29

Page 30

Optional Low Gas

Pressure

Switch

Manual Shutoff Valve (2nd furnace)

Dual, Single-Stage

Gas Valve (non-

modulating furnace)

Gas

Supply

Manual Shutoff Valve (1st furnace)

Ball Valve with Actuator (modulating furnace)

Dual, Single-Stage Gas Valve (modulating furnace)

Transducer

Optional High Gas Pressure Switch

Pressure Tap

Optional High Gas

Pressure Switch

4. Gas Heat Section Maintenance (cont'd)

4.3 Gas Train

FIGURE 15 - Gas Train Components

NOTE: Heat section Sizes 500, 600, 700, and 800 with one furnace have manifold for modulating furnace only.

Location: The gas train is visible with the heat section door open. See component identication in FIGURE 15.

Service: Carefully remove external dirt from the valves and check the wiring connec-

tions. Annually, in preparation for the heating season, check the dual, single-stage

operating valve to be sure that it shuts gas ow off completely.

If any gas valves or other gas train components need to be replaced, they must be replaced with identical part or factory-authorized replacement.

Dual Single-Stage Operating Gas Valve - All gas heat sections have one or two dual single-stage gas valves.

WARNING

he operating valve is the prime safety shutoff. All gas supply lines must be free of dirt or scale before connecting to the unit to ensure positive closure. See Hazard Levels, page 2.

FIGURE 16 - Top View of Dual Single-Stage Gas Valve

1/8” Outlet Pressure Tap

FIGURE 17 - Ball Valve and Actuator in Modulating Gas Control

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 30

3) Use your nger to fully block the burner orice. Continue blocking the orice for

several seconds and observe the manometers. If any pressure is indicated, the gas valve is leaking. A leaking gas valve must be replaced before the heater is put back in operation.

4) Repeat the test with each dual single-stage gas valve.

The dual single-stage gas valve(s) must be checked

annually to ensure that each valve is shutting off gas ow

completely. Instructions:

1) Locate the 1/8" NPT pressure taps on the

combination valve (see illustration on the left).

2) Turn the manual valve OFF to prevent ow to the manifold. Connect a manometer to both of the 1/8” outlet pressure taps. NOTE: Manometers (uid- lled gauges) with inches water column scale are

recommended. Turn the manual valve ON and the heater off.

The modulating furnace has a ball valve

with an actuator to control gas ow. The

ball valve and actuator are located downstream of the dual single-stage valve as shown here.

Carefully clean external dirt accumulation from the actuator.

Page 31

FIGURE 18 - Ball Valve with Actuator in Modulating Gas Control Manifold

Ball Valve Shaft

Ball Valve with actuator removed (for illustration only); do not remove actuator.

Modulating System Gas Valve (Ball Valve & Actuator) Adjustment

FIGURE 19 Gas Manifold Transducer

Inspect the position of the ball valve shaft.

• In the fully open position, the dash marks on the top of the shaft should be aligned

with the gas piping.

• In the fully closed position, the dash marks on the top of the shaft should be

aligned at a 90° angle across the gas piping.

If the ball valve shaft is not properly aligned or if the manifold pressure does not match the settings in the chart below, the ball valve will need to be adjusted.

Location: See FIGURE 15. Function: The transducer reads the manifold pressure and sets the venter motor

speed to precisely match the designed combustion settings. Service: If the transducer needs to be replaced, use only a factory-authorized replace-

ment part designed for the purpose.

Ball Valve Actuator

Modulates the Gas Flow

Actuator

Setscrew

(shown on the

right or closed

position)

Manifold Pressures for MAPSIII Cabinet D Gas Modulation System

*NOTE: Propane is

available on limited sizes with 2-stage gas control only. Manifold pressures (valve output) for those sizes are listed below.

Cabinet and Heat

Section Size

D-Cab - All Sizes Natural 3.4 0.20

Cabinet and Heat Section Size Gas Type High Setting 100% t Low Setting 50%

at the Pressure Tap by the Gas Transducer

D-Cab 1000 Propane 10.0 5.0

D-Cab 1200 Propane 10.0 5.0

D-Cab 1400 Propane 10.0 5.0

D-Cab 1600 Propane 10.0 5.0

Instructions

To check and/or adjust gas modulation:

Checking modulation requires a manometer capable

of reading to 0.10" w.c. Connect the manometer as instructed in Step 1.f) below.

To check and adjust the modulation system, the IQ

controller must be in Test Mode. On the control display in the electrical compartment, follow the steps below to enter Test Mode.

a) Scroll down to Menus and press Enter. b) Enter password (0000) using the INC button and

the right arrow button and press Enter. c) Scroll down to the Service Menu and press Enter. d) Scroll down to Test Mode and press Enter. e) Scroll down to Manual Test; press Enter; press the

Manifold Pressure (" w.c.) Measured

Gas Type*

INC button to change the command from OFF to ON; and press Enter.

f) After the system has completed the shutdown

sequence, connect the gas manometer to the

manifold pressure tap next to the transducer (See

FIGURES 15 and 19).

g) On the display, scroll down to Heat Stg 1 and press

Enter.

h) Scroll down to ModHeat which has a default setting

of 100%.

2. With the ModHeat set at 100%, measure the manifold pressure. If the manifold pressure matches the High Setting value in the chart above, continue to Step No.

High Setting

100% on ModHeat

Low Setting

0% on ModHeat

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 31

Page 32

4.0 Gas Heat Section Maintenance (cont'd)

4.3 Gas Train (cont'd)

Modulating System Gas Valve Adjustment Instructions (cont'd)

If the manifold pressure does not match the value in the chart and the ball valve is fully or close to fully open, adjust the pressure screws) on the Honeywell valve (See FIGURE 16) until the pressure matches the chart. Adjust both pressure screws so that they are the same. When the manifold pressure measured at the manometer matches the pressure listed in the chart, make a note for future reference of the position of the ball valve stem in relation to the dash marks on the actuator.

3. On the display, change the ModHeat setting to

0% modulation and allow the ball valve to go to its

lowest setting. Check the manifold pressure on the

manometer. If the manifold pressure matches the Low

Setting value in the chart, skip to Step No. 4.

If the manifold pressure does not match the low (0%)

value on the chart, the ball valve will need to be adjusted. Follow these steps:

a) While the unit is still ring at 0% modulation,

remove the ball valve actuator. To do this, locate the screw on the rear of the actuator and remove

it. Loosen the actuator set screw (See FIGURE

18), and carefully remove the actuator by lifting it

straight up. Do not disconnect any wires.

b) Using adjustable pliers, slowly turn the ball valve

stem until the manifold pressure on the manometer matches the low setting on the chart. Important NOTE: If the valve is adjusted too far

closed and the ame goes out, let the unit recycle

and then manually open the ball valve to the 100%

open position noted in Step No. 2. When the unit

is ring at full re, re-attach the actuator to the ball

valve, and repeat the procedure beginning with Step No. 2.

c) When the manometer readings match the values in

the chart and before re-installing the actuator, the burr left on the ball valve stem from the previous set screw setting needs to be removed. Either

lightly le the burr on the valve stem to prevent the

set screw from returning to the previous position or remove the valve stem, rotate it 180° so that the set screw contacts the opposite side of the stem, and re-install the valve stem.

d) Re-install the actuator making sure it is level on the

ball valve mounting plate.

e) Re-check the setting by going to full re (Set

ModHeat at 100%) and returning to 0% modulation

(Set ModHeat at 0%). Measure the manifold pressure. The adjusted gas pressure should be close to the value in the chart on page 31. If not, repeat the procedure.

4. When the settings are in agreement with the chart and testing is complete, remove the manometer. Set ModHeat to 100%. Scroll the display back to Test Mode and press Enter. Disable Test Mode by pressing the INC button to change the command from

ON to OFF; and press Enter.

FIGURE 20 - Optional Gas Pressure Safety Switches

Location: Low pressure switch is at the entrance to the gas train. The high pres- sure switch is at the burner end. See FIGURE 15.

Function: To monitor gas pressure and shut down the heat section if gas pres-

sure becomes too low or too high. The low pressure switch is an auto reset type.

The high pressure switch requires manual reset.

Service: The are no replaceable parts and the settings are non-adjustable. If

replacement is required, use identical factory-authorized safety switches.

4.4 Other Gas Heat Section Controls

FIGURE 21 Combustion Air Proving Switch

Location: See FIGURE 12, page 25, for location. Function: If the pressure switch does not sense combustion air ow from venter

operation, the controller will shut down heat section operation. Service: If it is determined that the pressure switch needs replacing, use only

the factory-authorized replacement part that is designed for the model and size of gas heater being serviced.

DANGER

Safe operation requires proper venting ow. Never bypass the combustion air

proving switch or attempt to operate the heat section without the venter running

and proper ow in the vent system. Hazardous condition could result. See Hazard

Levels, page 2.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 32

Page 33

Switch Settings and P/N's

Modulating Burner Full Rate -

Heat Section

Size

500 2.6 2.6 1.0 Brown 201160 600 2.8 2.8 1.4 Red 201159 700 2.4 2.4 1.0 Brown 201160

800 2.7 2.7 1.4 Red 201159 1000 2.6 2.6 1.0 Brown 201160 1200 2.8 2.8 1.4 Red 201159 1400 2.4 2.4 1.0 Brown 201160 1600 2.7 2.7 1.4 Red 201159

Heat Section

Size

1000 4.2 2.6 2.0 White 234054 1200 4.8 2.9 2.0 White 234054 1400 3.6 2.3 2.0 White 234054 1600 4.8 3.1 2.5 White 222860

Light Off

Gas Non-Modulating Burner Full

Light Off

Natural Gas

(Cold)

Rate - Natural Gas

(Cold)

Equilibrium

(Hot)

Equilibrium

(Hot)

Setpoint

OFF

Setpoint

OFF

Label Color

Switch

P/N

Switch

P/N

FIGURE 22 - Limit

Control

5.0 Electric Heat Section Maintenance - Models RECB and REDB

Electric Heating Elements and Controls

Location: A limit control is located in each heat section with the capillary sensor extend-

ing across the discharge side of the heat exchanger. Function: The limit control is a temperature sensitive safety device. If the temperature

setting of the limit control is exceeded, the controller will shut down operation of the heat section.

Service: The limit switch will automatically reset when the temperature drops. However, the cause for the limit activating should be found and corrected. If it is determined that a limit control needs replacing, use only a factory-authorized replacement part that is designed for the heat section size.

WARNING

Turn off the power locking the disconnect switch. Allow the heating elements to cool.

CAUTION: Wearing eye protection is recommended when

cleaning the heating elements and cabinet.

Location: Refer to FIGURE 24, page 34.

Service: Check the heating elements at the beginning of the heating season. The ele-

ments are assembled and attached to the electrical panel that is visible on the inner side of the electric heat section. Slide the panel out to access the elements. Carefully clean all dust and dirt from the heating elements using a brush or steel wool. With a vacuum or air hose, clean the inside of the cabinet especially the bottom and sides where dirt and dust will accumulate.

If a replacement is needed, order a complete heat section assembly.

FIGURE 23 - SCR Controller

Location: See the control location illustration in FIGURE 1, page 4, and FIGURE 24

for additional electric heat section control panels. The electric heat section has one or two SCR power controller(s), transformer, relay, digital controller, contactors, fuses, and distribution blocks.

Quantities and types of fuses and contactors depend on the size of unit.

DANGER

High voltages are present on the terminals of the SCR power controller(s).

If replacement parts are required, check with your distributor and use only factory-

authorized replacements.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 33

Page 34

Distributor

Blocks

Transformer

Grounding

Lug

Terminal

Blocks

Transformer

Pressure

Switch

Fuse Blocks

Typical Fuse Panel (located left

in the electric heat section)

Contactors

Bushing

SCR Controller(s) (see illustration above)

Terminal Block

Contactors

Terminal Blocks

Strain

Relief

Bushings

Access Panel attached to Electric

Element Assembly

(Slide out to remove element assembly.)

Sequencer(s)

5.0 Electric Heat Section Maintenance - Models RECB and REDB (cont'd)

Electric Heating Elements and Controls (cont'd)

FIGURE 24 Electric Heat Elements

Electric Heating Element

Cassette Assembly

(includes electric

heat elements)

Fuse Panel

(See FIGURE

25.)

Air Sensing Tube

Electric Heat Control Panel

(See FIGURE 25.)

FIGURE 25 - Location of Components on Control Panels in the Electric Heat Section

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 34

Page 35

6.0 Troubleshooting

6.1 Troubleshooting

- RCB, RDB, RDCB, RDDB, RECB, REDB

should only be performed by a qualied HVAC technician.

See Control Instructions for operation/maintenance/ service information on the unit controller.

NOTE: Unit is equipped with a phase loss/phase reversal control. If system does not

start, check phase of electrical supply.

DANGER:

This unit contains R-410A high pressure refrigerant. Hazards exist that could result in personal injury or death. Installation, maintenance, and service should only be

performed by an HVAC technician qualied in R-410A refrigerant and using proper

tools and equipment. Due to much higher pressure of R-410A refrigerant, DO NOT USE service equipment or tools designed for R22 refrigerant.

General Refrigeration Circuit - applies to all Models

SYMPTOM POSSIBLE CAUSE REMEDY

A. Compressor will not start.

B. Compressor starts but cuts out on low pressure (low pressure switch activates at 35 psig.)

C. Compressor starts but cuts out on high pressure switch.

D. Compressor cuts out on thermal overload.

E. Noisy compressor.

F. Noisy unit operation.

1. Power off, loose electrical connections or fuse open.

2. Compressor contactor not closing. 2. Check voltage to contactor coil, transformer, slave relay, system. Replace parts

3. Internal compressor thermal overload open. 3. If compressor is hot, allow 2 hours to cool. See D. below.

4. Compressor defective. 4. Check compressor for electrical failure. Compressor may be seized; check

5. High or low pressure switch open or defective. 5. If manual reset (high pressure), reset switch. (Switch opens at 600 psi and will

1. Low refrigerant charge. 1. Check subcooling; see Paragraph 3.5.

2. Airow restricted. 2. Check for dirty evaporator coil, dirty lters, dampers closed, iced evaporator coil,

3. Restriction in refrigerant line. 3. Check subcooling and superheat (Paragraph 3.5). Check operation of the

4. Defective low pressure switch. 4. Check switch (opens 35 psi; closes 50 psi). If defective, replace low pressure

1. Refrigerant overcharge. 1. Check subcooling; see Paragraph 3.5.

2. Condenser fan motor defective. 2. Check fan motor.

3. Condenser coil inlet obstructed or dirty. 3. Check coil and inlet clearances and for possible air recirculation.

4. Air or non-condensables in system. 4. Check high side equalized pressure reading with equivalent outdoor

5. Defective high pressure switch. 5. Check switch (opens 600 psi; proof 700 psi; manual reset allowed below 400

6. Restriction in discharge or liquid line. 6. Check subcooling and superheat (Paragraph 3.5). Check operation of thermal

1. Low voltage. 1. Check voltage.

2. Sustained high discharge pressure. 2. Check running amperage and conditions described in I.

3. High suction and discharge pressures. 3. Check thermal expansion valve operation, check for air in system.

4. Defective compressor overload. 4. If compressor is hot, allow compressor to cool for two hours. Recheck for open

5. Improper refrigerant charge. 5. Check subcooling (Paragraph 3.5).

6. Bearings or pistons too tight. 6. Check for low oil level.

7. Allow time for compressor to cool. 7. Check dome temperature of the compressor.

1. Reverse rotation. 1. Check at startup. If the suction pressure rises and discharge pressure drops,

2. Refrigerant overcharge. 2. Check pressures and subcooling (Paragraph 3.5).

3. Liquid oodback. 3. Check thermal expansion valve setting. Check subcooling for refrigerant

4. Tubing rattle. 4. Dampen tubing vibration by taping or clamping. Carefully bend tubing away from

5. Compressor defective. 5. Check internal parts. Replace defective parts or compressor.

1. Blower rotational noise. 1. Check blower, motor and drive for faulty adjustment or noisy bearings, loose

2. Air noise. 2. Check ductwork. Air velocity too high.

3. Chattering contactor. 3. Check for adequate control voltage; check for shorts or breaks; check contact

4. Tubing rattle. 4. Dampen by taping or clamping, carefully bend tubing away from contact when

1. Check disconnect switch, fuses and wiring. Replace parts or repair as necessary

as necessary.

refrigerant. If necessary, replace compressor.

not reset above 400 psi.) If auto reset (low pressure) does not reset and everything else is OK, replace low pressure switch, P/N 216380.

and/or improper belt. Check motor amps. Check duct design.

thermal expansion valve. Check for pressure drop across the lter drier.

switch, P/N 216380.

temperature.

psi). If defective, replace high pressure switch, P/N 216379.

expansion valves.

circuit.

shut down the compressor. Switch the 3-phase wiring connections.

overcharge (Paragraph 3.5).

contact where possible.

parts, and/or blower out of balance.

points.

possible.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 35

Page 36

6.0 Troubleshooting (cont'd)

6.1 Troubleshooting - RCB, RDB, RDCB, RDDB, RECB, REDB (cont'd)

General Refrigeration Circuit - applies to all Models (cont'd)

SYMPTOM POSSIBLE CAUSE REMEDY

G. High suction pressure

H. High discharge pressure.

I. Suction pressure is too low.

J. Head pressure too low.

K. Compressor short cycles.

L. Running cycle

is too long or unit operates continuously.

M. Supply air temperature is too high.

N. Supply air temperature is too low.

O. Liquid line is

too hot.

1. Excessive load on evaporator coil. 1. Check superheat (Paragraph 3.5). Check for high entering wet bulb temperature.

2. Compressor is unloaded. 2. Check head pressure. Check thermal expansion valve. If valve is not functioning

3. Expansion valve bulb not secured to suction line or valve defective.

1. Refrigerant overcharge 1. Check subcooling. (Paragraph 3.5) Adjust refrigerant charge.

2. Thermal expansion valve setting 2. Check superheat and adjust valve as needed.

2. Air inlet to condenser dirty or obstructed. 3. Check for proper clearances and possible air recirculating.

4. Condenser fan motor defective. 4. Check condenser fan motor(s).

1. Refrigerant undercharge. 1. Check subcooling. (Paragraph 3.5) Add refrigerant as needed.

2. Thermal expansion valve setting 2. Check superheat and adjust valve as needed.

3. Blower running backward. 3. Interchange any two wires from 3 phase disconnect.

4. Loose blower, pulley, or belts. 4. Check drive pulley alignment and belt tension.

5. Dirty lter. 5. Check lter and evaporator coil.

6. Too little air ow or low entering air

temperature.

7. Restriction in suction or liquid line. 7. Check refrigerant circuit for restriction.

1. Insufcient refrigerant charge. 1. Check subcooling (Paragraph 3.5). Check for leak. Repair and add refrigerant.

2. Defective or improperly adjusted expansion valve.

3. Low suction pressure. 3. See “I. Suction pressure too low” above.

4. Defective compressor. 4. See "G. High suction pressure” above.

1. Improper refrigerant charge. 1. Check subcooling and superheat. (Paragraph 3.5)

2. Defective high or low pressure control. 2. Check high or low pressure switch.

3. Liquid oodback. 3. Possible tight bearings, see above.

4. Defective expansion valve. 4. Check superheat and thermal expansion valve.

5. Poor air distribution. 5. Check ductwork for recirculating.

6. High discharge pressure. 6. See “H. High discharge pressure” above.

7. Leaking discharge valves in compressor. 7. See “G. High suction pressure” above.

1. Refrigeration undercharged. 1. Check subcooling (Paragraph 3.5) and add refrigerant.

2. Dirty lter or evaporator coil. 2. Check lter, coil, and airow. Clean and/or replace.

3. Dirty or clogged condenser coil. 3. Check coil and airow. Clean.

4. Air or other non-condensables in system. 4. Check equalized high side pressure with equivalent outdoor temperature.

5. Defective compressor. 5. See “G. High suction pressure” above.

6. Restriction in suction and liquid line. 6. Check for restrictions in refrigerant circuit.

7. Control contacts stuck. 7. Check wiring.

1. Refrigerant undercharge or leak in system. 1. Check subcooling (Paragraph 3.5). Check for leak. Repair and add refrigerant.

2. Evaporator plugged with dirt or ice. 2. Check evaporator, airow, and lter. Clean.

3. Improperly adjusted or defective expansion valve.

4. Defective compressor. 4. Check compressor for proper operation.

5. High discharge pressure. 5. See “H. High discharge pressure” above.

6. Airow is too high. 6. Check external static pressure.

1. Airow is too low. 1. Check evaporator coil; check lters; check for closed dampers or grills; check

2. Return air temperature too low. 2. Check entering air wet bulb conditions.

1. Refrigerant undercharge. 1. Check subcooling.

2. High discharge pressure. 2. See H. above.

Check for excessive air.

properly, check pressure drop across lter drier.

3. Check the thermal expansion valve; ensure bulb is attached properly and

insulated

6. Check airow and entering air wet bulb conditions.

2. Check superheat (Paragraph 3.5) and adjust thermal expansion valve.

3. Check superheat (Paragraph 3.5) and adjust thermal expansion valve. Check expansion valve bulb placement and insulation.

drive for loose parts, belts, or misalignment; and check external static pressure.

6.2 Troubleshooting Heat Section

6.2.1 General Troubleshooting - Electric Heat Section, Models RECB and REDB

PROBLEM PROBABLE CAUSE REMEDY Unit does not operate

Fan operates but element does not heat

Insufcient

heat

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 36

1. No power to unit 1. Turn on power; check supply fuses or main circuit breaker.

2. Blown fuses 2. Check and replace if necessary.

3. Defective or incorrect wiring. 3. Check wiring and connections. Refer to wiring diagram provided with unit.

4. Defective or burned out control transformer 4. Check secondary voltage with voltmeter. Replace if necessary.

1. Dirty lters 1. Check lters and clean or replace if necessary.

2. Defective air proving switch 2. Check and replace if necessary.

3. Blown element fuses 3. Check and replace element fuses if necessary.

1. Burned out element 1. Turn off power and check element resistance with ohmmeter. Replace if open.

2. Blown fuses 2. Check and replace if necessary.

3. Cycling on limit control 3. a) Check air throughput (temperature rise). b) Check motor rpm against nameplate rating. Replace motor if speed is too slow. c) Defective limit control. Check wiring and connections. Check continuity through control and replace if necessary.

4. Defective or incorrect wiring. 4. Check wiring and connections. Refer to wiring diagram provided with unit.

Page 37

6.2.2 General Troubleshooting - Gas Heat Section, Models RDCB and RDDB

PROBLEM PROBABLE CAUSE REMEDY

Venter motor

will not start

Burner will not light

Burner will not light (cont'd)

Burner cycles on and off

No heat (Heater Operating)

Venter motor

will not run

Venter motor

cuts out on overload

1. No power to unit. 1. Turn on power; check supply fuses or main circuit breaker.

2. No 24 volt power to ignition system circuit board. 2. Check control transformer output.

3. Integrated circuit board fuse blown. 3. Correct cause; replace fuse.

4. No power to venter motor. 4. Tighten connections at circuit board and/or motor terminals.

5. Integrated circuit board defective. 5. Replace integrated circuit board.

6. Defective venter motor or capacitor. 6. Replace defective parts. Recommend replacing capacitor when replacing motor.

1. Manual valve not open. 1. Open manual valve.

2. Air in the gas line. 2. Bleed gas line (initial startup only).

3. Gas pressure too high or too low. 3. See installation manual, Form I-MAPSIII&IV, Paragraph 9.2.2.

4. No Spark: 4. a) Loose wire connections. a) Be certain all wire connections are solid. b) Transformer failure. b) Be sure 24 volts is available. c) Incorrect spark gap. c) Maintain spark gap at 1/8". d) Spark cable shorted to ground. d) Replace worn or grounded spark cable. e) Spark electrode shorted to ground. e) Replace if ceramic spark electrode is cracked or grounded. f) Burner not grounded. f) Make certain circuit board is grounded to ignitor. g) Ignition system circuit board not grounded. g) Make certain circuit board is grounded to furnace chassis. h) Unit not properly grounded. h) Make certain unit is properly eld grounded to earth ground and properly

i) Ignition system circuit board fuse blown. i) Correct cause; replace fuse. j) Faulty circuit board. j) If 24 volt is available to the circuit board and all other causes have been

5. Lockout device interrupting control circuit by

above causes.

6. Combustion air proving switch not closing. 6.

7. Faulty combustion air proving switch. 7. Replace combustion air proving switch.

8. Valve not operating. 8. a) Defective valve. a) If 24 volt is measured at the valve connections and valve remains closed,

b) Loose wire connections b) Check and tighten all wiring connections.

9. Circuit board does not power valves. 9. a) Loose wire connections. a) Check and tighten all wiring connections. b) Flame sensor grounded. b) Be certain ame sensor lead is not grounded or insulation or ceramic is not

c) Incorrect gas pressure. c) See installation manual, Form I-MAPSIII&IV, Paragraph 9.2.2. d) Cracked ceramic at sensor. d) Replace sensor.

1. Gas pressure too high or too low. 1. See installation manual, Form I-MAPSIII&IV, Paragraph 9.2.2.

2. Burner not grounded 2. Make certain integrated circuit board is grounded to ignitor.

3. Circuit board not grounded. 3. Make certain integrated circuit board is grounded to furnace chassis.

4. Faulty integrated circuit board 4. If 24 volt is available to the circuit board and all other causes have been

5. Combustion air proving switch not closing. 5.

6. Faulty combustion air proving switch. 6. Replace combustion air proving switch.

7. Flame sensor grounded. 7. Be certain ame sensor lead is not grounded or insulation or ceramic is not

8. Cracked ceramic at sensor 8. Replace sensor.

9. Incorrect polarity. 9. Reverse line volt leads to integrated circuit board.

1. Incorrect valve outlet pressure. 1. Check valve outlet pressure. See Installation Form I-MAPSIII, Paragraph 9.2.2.

2. Cycling on limit control. 2. Check air throughput.

1. Circuit open. 1. Check wiring and connections.

2. Defective integrated circuit board. 2. Replace board.

3. Defective motor. 3. Replace motor.

1. Low or high voltage supply. 1. Correct electric supply.

2. Defective venter motor or capacitor. 2. Replace defective parts. Recommend replacing capacitor when replacing motor.

See Paragraph 4.1.3.

phased (L1 to hot lead L2 to neutral).

eliminated, replace board.

5. Reset lockout by interrupting control.

a) Remove obstructions from vent. b) Replace faulty tubing to pressure switch.

replace valve.

cracked. Replace as required.

eliminated, replace board.

a) Make sure unit is properly vented. b) Remove obstructions from vent. c) Replace faulty tubing to pressure switch.

cracked. Replace as required.

See Paragraph 4.1.3.

6.2.2.1 Troubleshooting the non-modulating furnace with Modulating Gas Control on Sizes

1000, 1200, 1400, and 1600

Check the Lights on the DSI Integrated Control Module (Ignition System Circuit Board)

The ignition system circuit board monitors the operation of the heater and includes two LED signal lights that indicate

normal operation and various abnormal conditions. If the heater fails to operate properly, check this signal to determine

the cause and/or to eliminate certain causes. See operating sequence in Paragraph 4.2.2.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 37

Page 38

6.0 Troubleshooting (cont'd)

6.2 Troubleshooting Heat Section (cont'd)

6.2.2 General Troubleshooting - Gas Heat Section (cont'd)

6.2.2.1 Troubleshooting the non-modulating furnace (cont'd)

Operating and Troubleshooting Indicator Lights on Control Module used on the nonmodulating furnace on Sizes 1000, 1200, 1400, and 1600

Do not attempt to repair the DSI integrated control module (circuit board); the only eld replaceable component is the

fuse. IMPORTANT: When using a multimeter to troubleshoot the 24 volt circuit, place the meter’s test leads into the 5 or 9 pin connectors located on the ignition control. Do not remove connectors or terminals from the electrical components. Doing so can result in misinterpreted readings due to the ignition control board’s fault mode monitoring circuits.

Control Status - Green LED Codes

Steady ON ...... Normal Operation, No call for heat

Fast Flash ....... Normal Operation, Call for heat

1 Flash ............ System Lockout, Failed to detect or sustain ame

2 Flashes ........ Pressure Switch Did Not Close within 30 Seconds of Venter Motor

3 Flashes ........ High Limit or Flame Rollout Switch Open

4 Flashes ........ Pressure Switch is Closed Before Venter Motor is Energized

Steady OFF .... Blown fuse, No Power, or Defective Board

Flame Status - Yellow LED Codes

Steady ON ...... Flame is sensed

Slow Flash ...... Weak ame (current below 1.0 microamps ± 50%)

Fast Flash ....... Undesired Flame (valve open and no call for heat)

Ignition Module Troubleshooting Flow Chart

YES

Is there

minimum flame

current at the control

module?

Check connections to

flame sensor or

moisture in bulkhead

connector.

current at the flame

YES

Is there

minimum flame

sensor?

Replace control

module.

Check gas pressure

and supply voltage. If

either are low, correct

YES NO

and repeat startup.

Does gas

ignite?

Is the

flame sensor

corroded?

Is the sensor

located in flame

correctly?

Repositon

flame sensor.

YES

position correct in the

Trial for Ignition

Call for Heat

YES NO

YES

Is the ignitor

gas flow?

Reposition

spark ignitor.

Is there a

spark across gap at

ignitor?

Clean flame

sensor.

Replace flame

sesnsor.

YES NO

Check wiring and

Is gas

flowing?

connections to

gas valve.

Is there

spark voltage at

control?

Is there

24V P1-2 to power

control?

Check wiring and/or 24VAC

transformer output.

Replace

gas valve.

YES

YES NO

Is there

24VAC at the gas

valve?

Is there

24VAC from gas

valve output on control

module

to chassis?

YES

Check high

voltage wire

continuity.

Replace control module.

Replace ignition control module.

6.2.2.2 Troubleshooting the Heat Section Control Module (deep modulation board) used with Modulating Gas Control

The control module (P/N 257246) that operates the furnace in a MAPSIII Cabinet D system has a built-in, self-diagnostic capability. The control continuously monitors its

own operation and the operation of the system. The LED on the control indicates the

current state, warnings, failures, and test modes. IMPORTANT NOTE: The troubleshooting information applies to the control board that

is standard on MAPSIII D Cabinet Models RDCB and RDDB manufactured beginning 8/2011. A Model RDCB or RDDB manufactured prior to 8/2011 may have this board.

The ignition board is identied as "96" in the Serial No. on the heat section rating plate.

Serial No. Sample: 3 BKH 789 BK 08 N 96 7D

If the ignition code in the serial number is 96, the following troubleshooting information applies. If the ignition code is 90, 91, 92, or 93, contact your representative or distributor or search RezSpec.com for a previous version of this manual.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 38

Page 39

Normal Furnace Operation Display

LED Display Heat Mode Description

OFF Mode (OFF) System Idle - Control board has power, no faults found, no call for heat.

System is purging the heat exchanger – No gas on, no ame, venter motor runs for the

PURGE Mode (Pur)

IGNITION Mode (Ign)

WARM-UP Mode (HEA)

- (Board Self Check)

RUN Mode (run) Normal modulating operation.

Ignition Retry (rEt)

specied purge timings. Purge cycles occur immediately before and after each burner

operation. System is initiating burner operation – Ignitor energized, modulating valve moved to

ignition setting, gas on. Maintained for the trial-for-ignition period and the ve-second ame stabilization period.

Period between Ignition and Run – System checks completed before modulation control begins.

System has had a failed ignition attempt or has lost ame during burner operation and

is beginning another ignition cycle.

Deep Modulation (Option AG70) Ignition Board is in the Heat Section (See FIGURE 12, page 25.)

IQ Controller Signal Input Terminals (J4)

Main Board Supply Power Input

Spades (L1 T1 and L2 T5)

Board Status

Voltage Output

to IQ (J7)

Board Power

and Signal (J6)

Control Board

Fuse (3A)

Plug Connection for Board Control Points (J8)

• Ball Valve Actuator Power, Drive Voltage, and Feedback Signal

• Off Board Digital Venter Air Pressure Switch and Unit

Primary Limit Switch

Gas Manifold PSI Transducer Plug 3-wire (red, black, and green) Wiring Connection (J13)

On board Air Pressure Sensor for Monitoring Inducer Pressure. Venter Sensing Tubing is connected from Venter housing to "LO" pressure input point on air sensing transducer.

J9, J10, J3, and J2 are not currently used.

Inducer Motor Main Power Connection Spades (IND-L2 T3 and IND-L1 T2)

Inducer Motor Capacitor Spade Connection (AUX-L2 T6)

Flame Sensor Spade Connection (T8)

ID Plug (unique by heat section size)

3 Character LED Display used to show deep modulation board codes for status, alarm, and error information.

Gas Heat Section Modulating Control FUNCTIONAL ALERTS

Code Alert Description Probable Causes Solutions

Failed ignition attempt (AO1)

Maximum number of allowed retries not met

The ame could not be

established during the trial for ignition period. This alert indicates the maximum number of retries has not been exceeded and furnace operation will continue with another ignition attempt.

See in the LOCKOUT ERRORS

section, pages 41-42.

See in the LOCKOUT ERRORS section, pages 41-42.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 39

Page 40

6.2 Troubleshooting Heat Section (cont'd)

6.2.2.2 Troubleshooting the Modulating Gas Control (cont'd)

Lost Flame

(AO2)

Insufcient

Combustion Air (AO3)

Furnace functional

Limited Low

Fire (AO4)

Gas Heat Section Modulating Control FUNCTIONAL ALERTS (cont'd)

The ame sensor signal has been lost after ame is established

during a call for heat. This alert is

displayed during the RECYCLE

period prior to the next ignition attempt.

Furnace cannot achieve

desired combustion air ow

due to blockage or high altitude operation resulting in a de-rate of the furnace.

Automatic adaptive program is currently limiting the lower range

of modulation at avoid ame loss at minimum re conditions. The

alert is displayed during the run

cycle once a ame-out condition has triggered the Limited Low

Fire function. This function is reset by cycling power to the board.

A. Flame sensor coated 1. Clean ame rod sensor.

B. Flame sensor improperly mounted or grounded

C. Unstable ame pattern 1. Verify that the spacing between the burner body and the

D. Insufcient intermediate gas

manifold pressure through main gas safety valve

E. Insufcient gas manifold

pressure to burner through modulating ball valve assembly

A. High altitude operation 1. Normal operation. Furnace automatically de-rates for high

B. Partially blocked vent 1 Check air inlet and outlet for blockage.

C. Leak in sensing hose 1. Check sensing hose for cracks, crimps, or loose

D. Low Line Voltage 1. Check the line voltage to the control board. Voltage should

E. Faulty venter assembly 1. Verify that the venter assembly is functioning properly by

A. Low gas line pressure 1. Ensure gas supply is connected to furnace and check for

B. Insufcient intermediate gas

manifold pressure through gas safety valve

C. Faulty burner operation 1. Check burner orice for proper size and blockage.

D. Faulty ame sensor 1. Check ame rod wiring and connections.

E. Improper alignment of the modulating actuator and the gas ball valve.

F. Blocked or improper venting 1. Check air inlet and outlet for blockage.

G. Improper jumper connection

on IQ UI-12 causing AO-4 to show on BacView as alarm and disables heat sequence.

1. Check ame sensor wiring integrity and ceramic for cracks.

2. Re-install / replace ame sensor.

burner shield is equal across the entire length of the burner.

2. Check that the seals between the heat exchanger header

and heat exchanger tubes are sound; refer to Paragraph

4.1.1.

3. Ensure that the heat section door gasket is in place and the doors are properly aligned

1. Check for faulty gas valve wiring.

2. Check 24 VAC to gas valve assembly.

3. Check inlet pressure to safety gas valve.

4. Check outlet pressure from the safety gas valve.

5. Replace safety gas valve if faulty.

1. Check voltage to gas valve actuator. (2-10 VDC depending

on model)

2. Check alignment and set screw connection between ball valve and actuator. See Paragraph 4.3.

altitude conditions.

2. Check venting conguration for excessive venting length,

improper sizing, etc.

connections.

be within 10% of nameplate.

referring to the sensing pressure chart on page 33.

proper line pressure.

1. Check for faulty gas valve wiring.

2. Check 24 VAC to gas valve assembly.

3. Check inlet pressure to safety gas valve.

4. Check outlet pressure from the safety gas valve – adjust as needed.

5. Replace safety gas valve if faulty.

2. Check for proper alignment of ame rod.

3. Clean ame rod sensor.

1. Check that the alignment of the actuator to the ball valve is correct. The valve must be in the fully open position when

the actuator is energized (ACTUATOR DRIVE = 9.6 VDC or

greater).

2. Ensure that the setscrew on the actuator is tightened to the ball valve stem.

2. Check venting conguration for excessive venting length,

improper sizing, etc.

1. Verify that the IQ heating feedback input is set to receive the ignition board voltage output of 0-10VDC from terminals J7 by making sure jumpers are set to receive 0-10VDC signal on UI-12 of the IQ controller.

Weak Flame Signal (AO5)

The ame signal level is less

than optimal for this furnace.

Maintenance of the ame sensing

components is advised.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 40

A. Flame sensor coated 1. Clean ame rod sensor. B. Flame sensor improperly mounted or grounded

C. Unstable ame pattern 1. Verify that the spacing between the burner body and the

1. Check ame sensor wiring integrity and ceramic for cracks.

2. Re-install / replace ame sensor.

burner shield is equal across the entire length of the burner.

2. Check that the seals between the heat exchanger header

and heat exchanger tubes are sound; refer to Paragraph

4.1.1.

3. Ensure that the heat section door gasket is in place and the door is properly aligned.

Page 41

Gas Heat Section Modulating Control LOCKOUT ERRORS

Code Alert Description Probable Causes Solutions

Ignition Board Failure (888)

Failed Ignition (EO1)

Maximum Retries (3) Exceeded

Primary Limit

/ Fuse Failure (EO2)

Modulation

Valve Failure

(EO3)

Air Sensor Failure (EO4)

Pressure Sensor Reading Low

Ignition board start-up checks have detected an error.

The ame could not be

established during multiple trial-for-ignition periods (3). The maximum number of retries has been exceeded and the furnace is in a lockout condition. System Shutdown alarm lockout will need to

be reset through BacView interface or IQ controller will

need to be power cycled.

The control board safety fuse has blown or the primary temperature limit has opened indicating safe operating temperatures for this furnace have been exceeded.

The control lost the position feedback from the modulating gas valve actuator.

The air sensor reading is too low for operating conditions or the air pressure switch closed when the sensor indicates

low ow

The pressure switch MUST be open prior to venter activation.

A. Faulty transformer 1. Check 24-volt transformer for correct output.

2. Check connections and wiring to control board and other components connected to the 24 volt source.

3. Replace if necessary.

B. Faulty control board 1. Turn off power to the furnace, wait 30 seconds and turn

A. Insufcient gas line

pressure B Gas valve control turned

“OFF”

C. No spark from direct spark ignition

D. Insufcient intermediate

gas manifold pressure through gas safety valve

E. Insufcient gas manifold

pressure to burner through modulating ball valve assembly

F. Burners do not light 1. Check spark rod assembly for proper location, spark gap,

G. Burners light and remain lit for about 5 seconds

A. Improper circulating

airow

B. Primary limit switch failure 1. Check for an open primary limit switch at ambient

C. Fuse is blown 1. Check and replace fuse on the board.

D. Faulty primary limit switch wiring A. Faulty modulation valve actuator wiring

B. Modulation valve actuator failure

A. Faulty wiring or connections

B. Faulty pressure switch 1. Replace pressure switch.

C. Faulty pressure sensor, located on the board

power back on. Re-try ignition sequence and see if the

system responds.

2. Replace control board if necessary.

1. Insure gas supply is connected to furnace and check for proper line pressure.

1. Turn gas valve to the “ON” position

1. Check ignition voltage (115 VAC from board to

transformer) and wiring.

2. Check 24 VAC transformer for DSI board.

1. Check for faulty gas valve wiring.

2. Check 24 VAC to gas valve assembly.

3. Check inlet pressure to safety gas valve.

4. Check outlet pressure from the safety gas valve – adjust as needed.

5. Replace safety gas valve if faulty.

1. Check voltage to gas valve actuator. (7 – 10 VDC

depending on model)

2. Check alignment and setscrew connection between ball valve and actuator (See procedure in Paragraph 4.3.).

etc.

2. Verify that the spacing between the burner body and the burner shield is equal across the entire length of the burner.

3. Check burner orice for proper size and blockage.

1. Check ame rod wiring and connections.

2. Check for proper alignment of ame rod.

3. Clean ame rod sensor.

1. Check lter / replace if dirty.

2. Check for improperly sized duct system.

3. Check for faulty blower motor.

4. Check for faulty blower motor wiring.

temperature.

2. Make sure fuse socket is tight, crimp fuse terminals if necessary.

1. Check primary limit wiring continuity from the switch to the control board.

1. Ensure wiring is connected per unit wiring diagram.

2. Check for loose pins or bad connections.

3. Check for frayed wiring or shorts to ground.

1. Ensure actuator has 24 V power.

2. Ensure actuator is receiving signal from the control board

(2-10 VDC).

3. Check for actuator feedback to the control board (2-10

VDC)

1. Check pressure switch wiring.

2. Check inducer wiring.

3. Check for plugged or disconnected vacuum hoses.

1. Replace board.

Air Sensor Failure (EO5)

Pressure Sensor Reading High

The air sensor reading is too high when the venter is off or the air pressure switch open when the sensor indicates

high ow.

The pressure switch MUST close to initiate an ignition sequence.

A. Faulty wiring or hose connections

B. Blocked or improper venting

C. Faulty pressure switch 1. Replace pressure switch.

1. Check pressure switch wiring.

2. Check venter motor wiring.

3. Check for broken or disconnected vacuum hoses.

1. Check air inlet and outlet for blockage.

2. Check venting conguration for excessive venting length,

improper sizing, etc.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 41

Page 42

6.2 Troubleshooting Heat Section (cont'd)

6.2.2.2 Troubleshooting the Modulating Gas Control (cont'd)

Gas Heat Section Modulating Control LOCKOUT ERRORS (ccont'd)

Code Alert Description Probable Causes Solutions

Gas Sensor Failure (EO6)

Pressure Sensor Reading Low

Gas Sensor Failure (EO7)

Pressure Sensor Reading High

Improper Flame Signal (EO8)

No Firing Rate Input (EO9)

Invalid I.D. Plug (Eid)

The gas transducer reading is too low compared to the expected value for the modulating gas valve actuator position.

When the furnace is operating at 75% or higher -- greater than 8 VDC analog input voltage - the manifold pressure sensor must read

1.4" w.c. or higher

The gas transducer reading is too high compared to the expected value for the modulating gas valve actuator position.

When the furnace is operating at 75% or lower - less than 8 VDC analog input voltage -the manifold pressure sensor must read 2.8" w.c. or lower.

Control senses ame present

when the gas valve is commanded off.

Call for heat is sensed (R & W

closed) but ring rate is below dened voltage threshold for

furnace operation.

The installed I.D. plug is not valid for this control board.

A. Modulating actuator/ball valve not properly aligned

B. Line pressure too low 1. Ensure line pressure is properly adjusted for the gas and

C. Intermediate regulated pressure to low

D. Wrong gas pressure sensor installed.

E. Gas pressure sensor faulty

A. Modulating actuator / ball valve not properly aligned

B. Line pressure too high 1. Ensure the line pressure is properly adjusted for the gas

C. Intermediate regulated pressure too high

D. Wrong gas pressure sensor installed

E. Gas pressure sensor faulty

A. Flame remains lit in “Off”

cycle

A. Faulty wiring into the

“Analog +” and “Analog –“

terminals

B. No signal from source. 1. Check ring rate input voltage – must be greater than 1.5

A. Incorrect I.D. plug installed 1. Ensure I.D. plug is correct for the furnace – check label.

1 Perform modulating system gas valve alignment

procedure; see Paragraph 4.3.

application. Correct as needed.

1. Ensure the safety gas valve(s) are properly adjusted

to the specied outlet pressure. Adjust per the installation

instructions as necessary.

1. Ensure the proper gas transducer - either natural gas or propane - is installed. Replace as needed.

1. Ensure gas manifold transducer is installed properly and wired per the unit wiring diagram. Replace as necessary.

1. Perform modulating system gas valve alignment

procedure; see Paragraph 4.3.

and application. Correct as necessary.

1. Ensure the safety gas valve(s) are properly adjusted

to the specied outlet pressure. Adjust per the installation

instructions as necessary.

1. Ensure gas sensor -- either natural or propane -- is installed. Replace as necessary.

1. Ensure gas sensor is installed properly and wired per the unit wiring diagram. Replace as necessary.

1. Gas valve leaks - check wiring to remove continuous 24V

to gas valve.

2. Gas valve is stuck open – remove, repair, or replace gas valve.

1. Ensure wiring is connected per unit wiring diagram.

2. Check for loose pins or bad connections.

3. Check for frayed wiring or shorts to ground.

VDC.

2. Troubleshoot controller providing ring rate input to the

deep modulation ignition control board.

2. Ensure I.D. plug is properly inserted into the mating connector on the control board.

3. With the I.D. plug installed, cycle power to the furnace. The board will display the I.D. plug identity upon power-up.

4. Install correct I.D. plug as needed.

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 42

Page 43

INDEX

Ball Valve and Actuator in

Gas Control Option AG70

30 Braze 14 Burner 21 Cleaning the Burner 23

Burner/Venturi Assembly 23

R410-A Refrigerant Charge

by Model Size and

Compressor 16 Charge the System 15 Coil Maintenance 7 Combustion Air Proving

Switch 32 Compressor Handling 11 Compressor Maintenance 10 Compressor Oil Charge 12 Compressors by Circuit 12 Condenser Fans 6 Condensing Coil Cleaning 7

Control Locations 4

Control Panels in the Electric

Heat Section 34

Damper Motor 19 Dampers and Damper

Controls 19 Digital Controller and

Sensors 19, 20

Variable Frequency Drive 20

DSI Integrated Control

Module 27

Heat section (electric) 3 electric elements 3 Electric Heating Elements 33 Electric Heat Section 5 Electric Heat Section

Maintenance - Models

RECB and REDB 33 Evacuate the Circuit 14 Evaporator Coil Cleaning 7

Condenser Fan 6 Filters 5 Filters from Outside Air Hood

5 Flame Sensor 24

Furnace Operation LED

Display 26

Gas Heat Section 21 Gas Manifold Pressure

Switch 31 Gas Pressure Safety

Switches 32 Gas Train for Modulating

Control (Option AG70) 30

Gas Valves 30

HAZARD INTENSITY

LEVELS 2

Heat Exchanger 21 Heat Section Controls 25 Outside Air Hood 5

Hot Gas Bypass Valve 20

ID Plug 39 Deep Modulation (Option

AG70) Ignition Board 39

Ignition Control Module

(Deep Modulation Board) 26

Ignition System for

Modulating Furnace with Gas Control Option AG70 26, 28

Ignitor 24

Limit Contro 33 Locations of Access Panels,

Standard and Optional Controls, and Service Ports 4

Maintenance Requirements

3 Maintenance Schedule 3 Manifold Pressures for Gas

Modulation System 31 Models RDCB & RDDB with

a gas heat section 3 Models RECB & REDB with

an electric heat section 3 Modulating Gas Control

Sequence of Operation 27

Modulating Reheat 21 Modulating System Gas

Valve (Ball Valve and

Actuator) Alignment 31 Adjust gas modulation 31 Motor and Blower 6

Re-Assemble the Heat

Exchanger Panel, Burner,

Gas Train, and Venter 25

REFERENCES 44 Refrigerant Pressure and

Temperatures 9

SCR Controller 33

Sensor Locations 20

Spark Board 26 Spark Gap 24 Motor Starter 20 Subcooling 17 Subcooling 9, 18 Subcooling 17 Recommended subcooling 9 Superheat 18

SUPERHEAT 9 Recommended superheat 9 Superheat 17 Dirty Filter Switch 5

Temperature/Pressure

Conversion Chart 10

Thermal Expansion Valves

Ignition Module

Troubleshooting Flow Chart 38

Troubleshooting - Electric

Heat Section, Models RECB and REDB 36

Troubleshooting - Gas Heat

Section, Models RDCB and RDDB 37, 38

Troubleshooting Ignition

Control System on the downstream (nonmodulating) furnace on Sizes 1000, 1200, 1400, and 1600 38

Troubleshooting - RCB, RDB,

RCDB, RDDB, RECB, REDB 35, 36

Troubleshooting Gas Heat

Section 36

Troubleshooting Ignition

Control System on the downstream (nonmodulating) furnace on Sizes 1000, 1200, 1400, and 1600 37, 38

Dual Single-Stage Operating

Gas Valve 30 Venter Assembly 22 Venter Maintenance 21 Venter Motor and Wheel 24 Venter Wheel Position 24 Voltage Imbalance 16 Voltage Protection 20

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 43

Page 44

REFERENCES

The Installation Manual, Control Instructions, this Operation/Maintenance Manual, and applicable supplier instructions are shipped with the unit. The literature listed below is currently available or will be soon at www.RezSpec.com or from your Reznor® Representative (1-800-695-1901).

Installation Manual, Form I-MAPSIII&IV for Cabinets A, B, C, & D Control Instructions, Form CP-MAPS D15/D16/D17/D18 Replacement Parts, Form P-MAPSIII&IV

Record installation information on the back of the

installation manual, Form I-MAPSIII&IV, for Cabinets A, B, C, & D.

Keep all booklets for future reference.

www.ReznorHVAC.com (800) 695-1901

Form O-MAPSIII Cabinet D, P/N 222918R9, Page 44

Trademark Notes: Reznor least the United States. All other trademarks are the property of their respective owners.

0514 Form O-MAPSIII Cabinet D (Version D.2)

, Tcore

, and MAPS

are registered in at

Reznor MAPS III User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual