Thermo Pride OH5-85DE User manual

MO-434
ECN 5647-MA 200813
ECM OPERATION MANUAL
FOR USE WITH MODELS:
OH5-85DE OL5-85FDE OL5-85RDE
OH11-105DE OL11-105FDE OL11-105RDE
OH2-56DE OL2-56FDE OL2-56RDE
OC5-85DE OC2-56DE OH5-85DXE
: IF YOU DO NOT FOLLOW THE SAFETY PRECAUTIONS BELOW AND IN THIS MANUAL, A
FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY, OR LOSS OF
LIFE.
DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN THE VICINITY OF
THIS OR ANY OTHER APPLIANCE.
INSTALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED INSTALLER, SERVICE AGENCY
OR THE GAS SUPPLIER. (REFERRED TO IN THESE INSTRUCTIONS AS A QUALIFIED HEATING
CONTRACTOR).
PLEASE READ THESE INSTRUCTIONS PRIOR TO INSTALLATION, INITIAL FIRING, AND BEFORE
PERFORMING ANY SERVICE OR MAINTENANCE. THESE INSTRUCTIONS MUST BE LEFT WITH THE
HOMEOWNER AND SHOULD BE RETAINED FOR FUTURE REFERENCE BY QUALIFIED SERVICE
PERSONNEL.
THERMO PRODUCTS, LLC.
BOX 2 7
DENTON, NC 272 9
MADE IN USA

All installations and services must be performed by qualified service personnel.
i
INDEX
SECTION BEGINNING PAGE
I. FURNACE SPECIFICATIONS (SHIPPED SETTINGS) 1
II. BLOWER CONTROL INFORMATION 4
A. TERMINAL DEFINITIONS & FIELD WIRING 4
B. WIRING & SWITCHES 5
C. INPUTS 9
D. OUTPUTS 9
E. OPERATING MODES 10
F. CFM TABLES 12
G. ECM SPECIFIC REPLACEMENT PARTS 1
III. ECM TROUBLESHOOTING 1
A. DIAGNOSTIC FEATURES 1
B. GENERAL GUIDELINES TO TROUBLESHOOTING GE ECM 14
C. TROUBLESHOOTING CHARTS 17

All installations and services must be performed by qualified service personnel.
1
I. FURNACE SPECIFICATIONS SHIPPED SETTINGS)
OL SERIES
MODEL NO. OL2-56 OL5-85 OL11-105
HEAT INPUT RATE IN BTU/HR
70,000 106,250 126,000
HEATING CAPACITY IN BTU/HR
56,000 85,000 101,000
HEIGHT OF CASING 4- /4” 4 -1/4” 46-1/2”
WIDTH OF CASING 19” 25” 25”
DEPTH OF CASING 48” 50-1/4” 54-1/2”
WARM AIR OUTLET 17 x 17 20 x 20 20 x 20
RETURN AIR INLET 17 x 17 20 x 14 20 x 16
DIA. OF FLUE OUTLET 5” 6” 6”
FLOOR-CENTER OF FLUE 29-1/4” 6” 8-1/2”
FLOWRATE from .2” & .5” w.c.
EXTERNAL STATIC PRESSURE COOLING COOLING COOLING
@2 TON SWITCH SELECTION CFM) 800 800 800
@2-1/2 TON SWITCH SELECTION CFM) 1000 1000 1000
@3 SWITCH SELECTION CFM) 1200 1200 1200
@3-1/2 TON SWITCH SELECTION CFM) 1400 1400 1400
HEATING HEATING HEATING
@70deg SWITCH SELECTION CFM) 7 7 11 4 1 5
APPROX TEMPERATURE RISE °F) 70 70 70
BLOWER MOTOR HP 1/2 1/2 1/2
NOZZLE SIZE .55 .75 .90
NOZZLE SPRAY ANGLE PATTERN 80º Hollow 80º Hollow 80º Hollow
LARGEST RECOMMENDED
AIR CONDITIONER .5 Ton .5 Ton .5 Ton
SIZE OF FILTERS 16” x 20” 20” x 20” 20” x 25”
NOTES:
1. Heating capacity based on annual fuel utilization efficiency rated by manufacturer.
2. On all outlet and inlet dimensions, the first dimension is width.
. To permit largest recommended air conditioning (at .5 static pressure), selection of the highest motor speed is
required.
4. Electrical characteristics at 115 volts, 60 Hz., 1 phase (less than 15 amps, for all models).
5. All specifications are subject to change without notice.

All installations and services must be performed by qualified service personnel.
2
OH SERIES
MODEL NO. OH2 OH5-85 OH11-105 OH5-85DXE
HEAT INPUT RATE IN BTU/HR
70,000 106,250 126,000
85,000
106,250
HEATING CAPACITY IN BTU/HR
56,000 85,000 101,000
74,000
85,000
HEIGHT OF CASING 52” 56” 59-1/2” 56”
WIDTH OF CASING 19” 24” 24” 24”
DEPTH OF CASING 27” ” 4” ”
WARM AIR OUTLET 17 x 17 22 x 20 22 x 20 22 x 20
RETURN AIR INLET 18 x 14 2 x 14 25 x 16 25 x 16
DIA. OF FLUE OUTLET 5” 6” 6” 6”
FLOOR-CENTER OF FLUE TOP TOP TOP TOP
FLOWRATE from .2” & .5” w.c.
EXTERNAL STATIC PRESSURE COOLING COOLING COOLING COOLING
@2 TON SWITCH SELECTION CFM) 800 800 800 726
@2-1/2 TON SWITCH SELECTION CFM) 1000 1000 1000 924
@3 SWITCH SELECTION CFM) 1200 1200 1200 1276
@3-1/2 TON SWITCH SELECTION CFM) 1400 1400 1400 1474
4 TON 1600
HEATING HEATING HEATING HEATING
@70deg SWITCH SELECTION CFM) 7 7 11 4 1 5
905
1121
APPROX TEMPERATURE RISE °F) 70 70 70 72
70
BLOWER MOTOR HP 1/2 1/2 1/2 /4
NOZZLE SIZE .55 .75 .90 .70
NOZZLE SPRAY ANGLE PATTERN 80º Hollow 80º Hollow 80º Hollow 45º W
LARGEST RECOMMENDED
AIR CONDITIONER .5 Ton .5 Ton .5 Ton 4 Ton
SIZE OF FILTERS 20” x 16” 25” x 16” 25” x 16” 20” x 25”
NOTES:
1. Heating capacity based on annual fuel utilization efficiency rated by manufacturer.
2. On all outlet and inlet dimensions, the first dimension is width.
. To permit largest recommended air conditioning (at .5 static pressure), selection of the highest motor speed is
required.
6. Electrical characteristics at 115 volts, 60 Hz., 1 phase (less than 15 amps, for all models).

All installations and services must be performed by qualified service personnel.
OC SERIES
MODEL NO. OC2-56 OC5-85
HEAT INPUT RATE IN BTU/HR
70,000 106,250
HEATING CAPACITY IN BTU/HR
56,000 85,000
HEIGHT OF CASING 57-1/2” 56”
WIDTH OF CASING 19” 24”
DEPTH OF CASING 27” ”
WARM AIR OUTLET 17 x 17 16 x 20
RETURN AIR INLET 17 x 17 22 x 20
DIA. OF FLUE OUTLET 5” 6”
FLOOR-CENTER OF FLUE TOP TOP
FLOWRATE from .2” & .5” w.c.
EXTERNAL STATIC PRESSURE COOLING COOLING
@2 TON SWITCH SELECTION CFM) 800 800
@2-1/2 TON SWITCH SELECTION CFM) 1000 1000
@3 SWITCH SELECTION CFM) 1200 1200
@3-1/2 TON SWITCH SELECTION CFM) 1400 1400
HEATING HEATING
@70deg SWITCH SELECTION CFM) 7 7 11 4
APPROX TEMPERATURE RISE °F) 70 70
BLOWER MOTOR HP 1/2 1/2
NOZZLE SIZE .55 .75
NOZZLE SPRAY ANGLE PATTERN 80º Hollow 80º Hollow
LARGEST RECOMMENDED
AIR CONDITIONER .5 Ton .5 Ton
SIZE OF FILTERS 17” x 10” 20” x 12”
NOTES:
1. Heating capacity based on annual fuel utilization efficiency rated by manufacturer.
2. On all outlet and inlet dimensions, the first dimension is width.
. To permit largest recommended air conditioning (at .5 static pressure), selection of the highest motor speed is
required.
7. Electrical characteristics at 115 volts, 60 Hz., 1 phase (less than 15 amps, for all models).
8. All specifications are subject to change without notice.

All installations and services must be performed by qualified service personnel.
4
BLOWER CONTROLLER INFORMATION
A. TERMINAL DEFINITIONS & FIELD WIRING
Burner Harness Connector P1
Pin 1 – Limit switch connection.
Pin 2 – 120 VAC Line connection.
Pin – Burner pilot contact.
Pin 4&5 – 120 VAC Neutral connection.
Pin 6 – Burner pilot contact.
Pin 7&8 – From oil primary control.
Pin 9 – Limit Switch Input (LSI).
Field Wiring to Burner
Pilot (Tstat) Neutral Line
Harness Wires
Beckett Connections
Riello Connections
Yellow Wires White Red
T-T terminals White Black
T-stat terminals White Black
Thermostat/Humidistat connections
"C" Common/ground
"W" Thermostat call for heat
"R" 24 VAC to thermostat
"G" Thermostat call for fan
"Y" Thermostat call for cool
“DEHUM” Humidistat call for dehumidification (TXV systems ONLY)
Thermostat/Humidistat connections for 2-Stage control
"C" Common/ground
"W1" T-Stat call for heat (low fire)
"W" T-Stat call for heat (high fire)
"R" 24 vac to T-Stat
"G" T-Stat call for fan
"Y" T-Stat call for cool
“DEHUM” Humidistat call for dehumidification (TXV systems ONLY)
ECM control outputs
Pin 1 - Speed Common Pin 4 – Blower Enable
Pin 2 - Speed Output Pin 5 – COOL Enable
Pin – Motor CFM Pin 6 – “R” Output
Male quick connect terminals.
"S1- ” 120 VAC Hot
“N1-7” 120 VAC Neutral
“EAC” Electronic Air Cleaner (120 VAC) connection.
“HUM” Humidifier connection (120 VAC).
"FAN" Fan On Signal
“X” 24VAC from transformer.
“C” 24VAC common from transformer.
"CC" Compressor Contactor
"CC_COM" Compressor Contactor Common

All installations and services must be performed by qualified service personnel.
5
B. WIRING & SWITCHES
HIGHBOY/LOWBOY
Figure 1: BLOWER WIRING

All installations and services must be performed by qualified service personnel.
6
: TURN OFF THE ELECTRICAL POWER to the furnace before attempting to isconnect blower
wiring.
COUNTERFLOW
Figure 2: BLOWER WIRING

All installations and services must be performed by qualified service personnel.
7
: TURN OFF THE ELECTRICAL POWER to the furnace before attempting to isconnect blower
wiring.
OH5-85 DXE
2-STAGE
Figure 3: BLOWER WIRING

All installations and services must be performed by qualified service personnel.
8
: TURN OFF THE ELECTRICAL POWER to the furnace before attempting to isconnect blower
wiring.
Figure 2: BOARD LAYOUT WITH SWITCHES
BLOWER
CFM

All installations and services must be performed by qualified service personnel.
9
C. Inputs
Power supplies
Line voltage is applied between the "S1" and "N1" quick connect terminals.
24 VAC Class II Transformer secondary voltage supplied to X and C
Limit Switch
The 120VAC optically isolated limit switch input is connected on pin P2-1 & 9. Refer to the Heat Mode
section for the control operation.
Thermostat call for heat "W"
24 VAC thermostat input. A call for heat is recognized when the thermostat connects "W" to "R". This
input has an indicator LED that will light when the control receives a call for heat. Refer to the Heat
Mode section for the control operation.
Thermostat call for heat “W2”
24 VAC thermostat input. A call for heat is recognized when the thermostat connects "W2" to "R". This
input has an indicator LED that will light when the control receives a call for heat. Refer to the Heat
Mode section for the control operation.
Thermostat call for cool, "Y"
24 VAC thermostat input. A call for cooling is recognized when the thermostat connects "Y" to "R. This
input has an indicator LED that will light when the control receives a call for cooling. . Refer to the Cool
Mode section for the control operation.
Thermostat call for dehumidification "DEHUM”
24 VAC thermostat input. A call for dehumidification is recognized when the humidistat connects
"DEHUM" to "R". This input has an indicator that will light when the control receives a call for
dehumidification. Refer to the Cool Mode section for the control operation.
Thermostat call for fan "G"
24 VAC thermostat input. A call for fan is recognized when the thermostat connects "G" to "R". This
input has an indicator LED in that will light when the control receives a call for fan. Refer to the Fan
Mode section for the control operation.
D. Outputs
ECM Control
The control controls a multiple speed ECM motor through the 6-pin P connector. This connector
provides connection for ECM Speed common (Pin 1), Speed output (Pin 2), Blower Enable (Pin 4), Cool
Enable (Pin 5) and “R” output (Pin 6).
Oil Burner
Control
The control provides dedicated contacts to operate the T-T input of an oil primary control.
Rating shall be class 2 - 24 VAC pilot duty @ 24 VAC (< 200mA).
Power

All installations and services must be performed by qualified service personnel.
10
The switched 120VAC power from the LIMIT switch passes through the board between Pins 1&2
of connector P1.
Compressor contactor
The control provides switched 24VAC to operate a compressor contactor. Rating shall be class 2 - 24
VAC pilot duty @ 24 VAC (< 200mA).
EAC (electronic air cleaner)
The control provides a 120VAC output for an electronic air cleaner. This output is energized whenever the fan
motor is energized (either low, heat or cool speed). Connection is made via male quick connect terminal
labeled "EAC".
Humidifier
The control provides a 120 VAC output for a humidifier. Connections are made to a male quick connect
terminal labeled "HUM". The control does not switch this output, it provides a pass-through connection from
P1-7 from the switched primary voltage of the Burner Module.
Status LED
A red LED is provided to indicate any thermostat input has been recognized by the microprocessor on the
control. See Diagnostic Features for a function description of operation.
Thermostat Input LEDs
Four green LEDs are placed beneath their respective thermostat connections (W, Y, G and DEHUM) and
operate whenever a call is present. See Diagnostic Features for a function description of operation.
Motor CFM LED
This green LED will flash once for every 100CFM the blower is producing.
E. Operating Modes
Standby Mode
All outputs are off and the control is waiting for a thermostat demand. The thermostat inputs, and limit
switch are continuously monitored. The control initiates action when a thermostat call is received or limit
switch opens.
Fan Mode
A call for fan ("G") is received from the thermostat. If no other mode is calling for blower operation, the
control will choose a “Low” speed value from the position of DIP switch SW1 positions 4 through 6, as
shown in the CFM Tables and operate the fan at that speed. The fan mode will be operated as long as the
"G" input is calling and neither the Heat mode nor the Cool mode is calling for blower operation. When the
Heat and Cool modes call for blower operation, their respective outputs will take over after their respective
turn-on time delays have expired. The speed Output is present until the fan call is satisfied.
Cooling Mode
A call for cool ("Y") is received from the thermostat. If the heat mode is not active or the anti-short cycle
delay is not in effect, the control will energize the “CC” terminal. After a 10 second delay blower ramps up to
the “COOL” speed determined by the position of DIP switch SW1 (positions 4 through 6) determine a speed as
shown in CFM Tables.
When the call for cool is satisfied, the “CC” terminal is de-energized and the cooling off delay of 45 seconds is
started. Forty-five seconds later the blower speed ramps toward zero and the control reverts to Standby Mode.

All installations and services must be performed by qualified service personnel.
11
Dehumidification Operation
If a call for dehumidification is received while the Cool Mode is active, blower speeds will be reduced.
The speed value will be selected from the DEHUM column of the CFM Tables. This input may only be
used on systems using a thermostatic expansion valve (TXV) on the evaporator.
Anti-Short Cycle Operation
To prevent compressor short cycling, a call for cooling will be ignored for four minutes after the
termination of any cooling call. The anti-short cycle delay is also in effect at power-up.
Heat Mode
When a call for heat ("W") is received from the thermostat, if the “Cool” mode is not already active, the “T-T”
terminal is energized and the blower on delay is started. The on-off pattern of DIP switch SW2 (positions 1
and 2) select one of four blowers on delay values (see Table 1). When the delay time has elapsed, a speed
value is read from DIP switch SW1 positions 1 through (see the CFM Tables) and the blower is ramped up
to that speed. The 2-Stage control will be operated by t-stat through W1 and W2. For 2-stage control with a
single stage t-stat, call for heat will go through W2. When W2 is energized, low fire is activated for 15
minutes. If a call for heat still exists, high fire will be activated and will continue until the demand for heat
has been satisfied.
Counterflow units, in addition, will run at a low blower speed shortly after the burner is brought on. They will
continue at that speed until the delay time has elapsed.
The control remains in steady heat mode until the thermostat is satisfied. When the call for heat signal is
removed, the “T-T” terminal is de-energized and the blower off delay is started. The on-off pattern of DIP
switch SW2 (positions and 4) select one of four blower off delay values (see Table 1). When the delay time
has elapsed, the blower is ramped toward zero.
Table 1: ON and OFF Blower Delay Time Switch Settings
DIP SWITCH 2 SECTION
STATE
BLOWER DELAY
TIMES
2 1 4 ON - SEC OFF - MIN
OFF OFF 0
OFF ON 60
ON OFF 120 Factory Set
ON ON 240
OFF OFF 2
OFF ON 4
ON OFF 6 Factory Set
ON ON 8
Motor Blower Speed
Three blower speed outputs are provided. A “G” call for fan will provide the Low speed only. A “W”
heat call will provide the Heat speed only. A “Y” cooling call will provide the Cool speed only.
In the case of thermostat calls for “Y” and “W” together, blower speed selection will be determined by the
input that was first initiated. In the case where the control is in a cooling mode with both “Y” and “W”
inputs energized and then the “Y” input is removed, the cooling blower off time will be executed prior to
the control switching into a heating mode. In the case where the control is in a heating mode with both
“Y” and “W” inputs energized and then the “W” input is removed, the heating blower off time will be
executed prior to the control switching into a cooling mode. In the case where a call for fan “G” already
exists and either a “W” or a “Y” call is initiated, the blower speed will switch to the respective “W” or a
“Y” speed following the blower on delay for that call.

All installations and services must be performed by qualified service personnel.
12
Six dip switches select Speed values for heat, cool, fan and dehumidification blower speeds (see the CFM
Tables).
Blower On and Off Delays
Four Heat blower on and four blower off delays are selected by two dip switches for each function. Refer to
Table 1 for specific delay values.
Speed Selection values
Three dip switches select 8 cooling speeds. Dependant fan, and dehumidification speeds are selected by
the same switches, their tabular values are enacted when their function is called.
Three additional dip switches select 8 heating speeds which are enacted when heat is called. This allows
independent selection of heating and cooling capacity parameters. See the CFM Tables for speeds.
F. CFM TABLES
The following tables contain blower speed settings and their respective air flowrates for the ECM blower motor.
To change air flowrates from that of the shipped settings, use the respective SW1 dipswitch on the furnace’s
integrated control board (see Figure 2).
COOLING SPEEDS HEATING SPEEDS & TEMPERATURE RISE
°F Rise CFM °F Rise CFM °F Rise CFM
COOL
LOW
DEHUM
3-OFF
6-OFF
2-OFF
5-OFF 560 1-OFF
4-OFF
3-OFF
6-OFF 2-OFF
5-OFF 1-ON
4-ON
3-OFF
6-OFF 2-ON
5-ON
840
1-OFF
4-OFF
3-OFF
6-OFF 2-ON
5-ON 980 1-ON
4-ON
3-ON
2-OFF
6-ON 1-OFF
5-OFF
1120
3-ON
4-OFF 2-OFF
1-ON
Facto y shipped
3-ON
settings
2-ON
1-OFF
3-ON
2-ON
1-ON
Ope ating Conditions
A e NOT App oved
7002.5 1000 500
1400 700
3 1200 600
ALL UNITS
2 800 400
SW 1
switch
settings Tons
CFM
4
3.5
SW1
switch
settings
OH2, OL2, OC2 OH5, OL5, OC5 OH11, OL11
82 636
75 696
69 756
63 828 82 966
1125
69 1148 77 1230
58 900 75
63 1260
841050
70 1350
56 1400 63 1500
1500 800
ADDITIONAL OH11, OL11 SETTINGS ONLY

All installations and services must be performed by qualified service personnel.
1
OH5 2-STAGE
OH5 2-STAGE
Facto y shipped
settings
G. ECM SPECIFIC REPLACEMENT PARTS
Part Name OH5/OH2 OH11 OL5/OL2 OL11 OC5/OC2 OH5
2-STAGE
ECM Motor AOPS7443/
AOPS7449
AOPS7444 AOPS7445/
AOPS7450
AOPS7446 AOPS7448/
AOPS7447
AOPS7454
Control Board 350915 350915 350915 350915 350915 350184
Motor Power Harness 350917 350917 350918 350918 350917 350917
Motor Control Harness 350920 350920 350921 350921 350920 350183
Burner Harness 350916 350916 350916 350916 350928 350182
Transformer 350464 350464 350464 350464 350464 350464
III. ECM TROUBLE SHOOTING
A. DIAGNOSTC FEATURES
The control board is equipped with 4 green Input Status LEDs and 1 red Board Status LED. These are intended to
provide a quick view into furnace performance without requiring a voltmeter.
The green Input Status LEDs are driven by the “Y”, “W”, “G”, and “DEHUM” inputs and are located directly
below those inputs. They will light to indicate the presence of these signals.
S 1
SETTING TONS
CFM
COOL LO
6 OFF
5 OFF
4 ON 2 726 352
6 OFF
5 OFF
4 ON
2.5 924 462
6 OFF
5 ON
4 ON
3 1276 638
6 ON
5 OFF
4 OFF
3.5 1474 726
6 ON
5 OFF
4 ON
4 1600 814
S 1
SETTING
LO FIRE
CFM RISE
HIGH FIRE
CFM
RISE
3 OFF
2 ON
1 OFF
800 81 1008 78
3 OFF
2 ON
1 ON
905 72 1121 70
3 ON
2 OFF
1 OFF
960 68 1200 66

All installations and services must be performed by qualified service personnel.
14
The red Board Status LED has two functions:
It will light when the board recognizes a valid input signal and will stay lit until all valid signals are removed.
This is intended to show that the board is functioning and able to respond to input signals.
It will flash rapidly while120VAC is missing from the LIMIT switch. This is intended to give a quick visual
indication of the High LIMIT switch.
B. GENERAL GUIDELINES TO TROUBLESHOOTING GE ECM – DRIVEN SYSTEMS
: Disconnect power from unit before removing or replacing connectors, or servicing motor.
Wait at least 5 minutes after disconnecting power before opening motor.
SYMPTOM CAUSE/PROCEDURE
Motor rocks slightly when starting  This is normal start-up for ECM
Motor won’t start
 No movement
 Check power at motor
 Check low voltage (24 VAC R to C) at motor
 Check low voltage connections
(G,PWM,W,R,C,) at motor
 Check for unseated pins in connectors on motor
harness
 Test with a temporary jumper between R – G
 Check motor for tight shaft
 Perform motor/control replacement check
 Run Moisture Check
 Motor rocks, but won’t start  Check for loose or compliant motor mount
 Make sure blower wheel is tight on shaft
 Perform motor/control replacement check
Motor oscillates up & down while being tested off
of blower
 It is normal for motor to oscillate with no load on
shaft.
Motor starts, but runs erratically
 Varies up and down or intermittent  Check line voltage for variation or “sag”
 Check low voltage connections
(G,PWM,W,R,C,) at motor, unseated pins in
motor harness connectors
 Check “Bk” for erratic CFM command (in
variable speed applications)
 Check-out system controls – T’stat?
 Perform Moisture Check
 “Hunts” or “puffs” at high CFM (speed)  Does removing panel or filter reduce “puffing”?
 Reduce restriction
 Reduce max airflow
 Stays at low CFM despite system call for cool or
heat CFM
 Check low voltage (T’stat) wires and connections
 Verify fan is not in delay mode – wait until delay
complete
 “R” missing/not connected at motor
 Perform motor/control replacement check
 Stays at high CFM  “R” missing/not connected at motor
 Is fan in delay mode? – wait until delay time
complete
 Perform motor/control replacement check
 Blower won’t shut off  Current leakage from controls into G,Y or W?

All installations and services must be performed by qualified service personnel.
15
Check for Triac switched t’stat or solid state
relay
Excessive noise  Determine if it’s air noise, cabinet, duct or motor
noise – interview customer, if necessary
 Noisy blower or cabinet  Check for loose blower housing, panels, etc.
 High static creating high blower speed?
 Check for air whistling thru seams in ducts,
cabinets or panels
 Check for cabinet/duct deformation
 “Hunts” or “puffs” at high CFM (speed)  Does removing panel or filter reduce “puffing”?
 Reduce restriction
 Reduce max airflow
Evidence of Moisture
 Motor failure or malfunction has occurred and
moisture is present
 Replace motor and perform Moisture Check
 Evidence of moisture present inside air mover  Perform Moisture Check
DO DON’T
 Check-out motor, controls, wiring and
connections thoroughly before replacing motor
 Automatically assume the motor is bad.
 Orient connectors down so water can’t get in
 Install “drip loops”
 Locate connectors above 7 and 4 o’clock
positions
 Use authorized motor and control model #’s for
replacement
 Replace one motor or control model # with
another (unless an authorized replacement)
 Keep static pressure to a minimum:
 Recommend high efficiency, low static
filters
 Recommend keeping filters clean
 Design ductwork for min static, max
comfort
 Look for and recommend ductwork
improvement, where necessary, in
replacement
 Use high pressure drop filters – some have ½”
H2O drop!
 Use restricted returns
 Size the equipment wisely  Oversize system then compensate with low
airflow
 Check orientation before inserting motor
connectors
 Plug in power connector backwards
 Force plugs
Moisture Check
 Connectors are orientated “down” (or as recommended by equipment manufacturer)
 Arrange harnesses with “drip loop” under motor
 Is condensate drain plugged?
 Check for low airflow (too much latent capacity)
 Check for undercharged condition
 Check and plug leaks in return ducts, cabinet
Comfort Check
 Check proper airflow settings

All installations and services must be performed by qualified service personnel.
16
 Low static pressure for lowest noise
 Set low continuous-fan CFM
 T’stat in bad location?
Figure 3: ECM PIN CONNECTORS
Troubleshooting table above and Figure 2 adapted from GE Industrial Systems publication GED-7161C,
“Troubleshooting GE ECM – Driven Systems”.

All installations and services must be performed by qualified service personnel.
17
C. TROUBLESHOOTING CHARTS
CONFIRM IF EITHER BLOWER
WHEEL IS RUBBING AGAINST
HOUSING OR MOTOR SHAFT
IS SPINNING FREELY, REPAIR
OR REPLACE AS NECESSARY.
DOES BLOWER SPIN FREELY?
IS THERE 115V
SUPPLIED TO MOTOR?
CHECK 115V SUPPLY,
CONNECTION FUSES,
SERVICE SWITCH AND
DOOR SWITCH.
CHECK HARNESS
CONNECTIONS
AND WIRE.
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
DISCONNECT 16 PIN
HARNESS FROM
MOTOR. IS THERE 12VDC
ACROSS PIN12 & PIN1
AND PIN12 & PIN3
AT THE HARNESS PLUG?
CHECK CONNECTION ON HARNESS AND MOTOR,
RECONNECT HARNESS TO MOTOR, IF
CONNECTIONS ARE GOOD AND MOTOR STILL
DOES NOT RUN REPLACE MOTOR.
THIS GUIDE SHOULD BE USED IN THE CASE OF A STOPPED OR MANFUNCTIONED ECM
BLOWER MOTOR. THE FOLLOWING SHOULD HELP ESTABLISH THE TYPE OF
MALFUNCTION OR DEVIATION FROM THE NORMAL BLOWER OPERATION.
TO USE THIS DIAGRAM, YOU JUST NEED TO FOLLOW THE INSTRUCTIONS IN THE BOXES.
CHECK 24VAC
SUPPLY
TO INTEGRATED CONTROL.
IS THERE 24VAC
ACROSS R &
B/C ON THE
INTEGRATED
CONTROL?
REPLACE
INTEGRATED
CONTROL.
TURN THERMOSTAT MANUAL FAN
SWITCH ON (IF AVAILABLE) OR JUMPER
BETWEEN R & G ON INTEGRATED CONTROL.
IS THERE VOLTAGE GREATER THAN
12VDC BETWEEN PIN15 & PIN1?
CHECK CONNECTIONS AND WIRES
AT INTEGRATED CONTROL, IF OK
REPLACE INTEGRATED CONTROL.
DISCONNECT 16PIN
HARNESS FROM
INTEGRATED CONTROL.
IS THERE 12VDC ACROSS
PIN 6 & PIN 1
AT THE CONROL?

All installations and services must be performed by qualified service personnel.
18
BLOWER Off-
Delay Active?
Sequence of Ope ation
BURNER On
1. A/C Off
2. COOL mode Off
3.BLOWER Off-Delay Sta ted
4. Status LED Off
BLOWER
= LOW
BLOWER = COOL
COOL
Mode On?
Y
Active?
On-Delay
Ended?
Yes Yes
Yes
Yes
No No No
No
DEHUM
Active?
BLOWER = LOW
1. BLOWER Off (No Delay)
2. Status LED Off
1. HEAT mode On
2. BLOWER = HEAT
3. Status LED Flashes
1. COOL mode On
2. Blowe On-Delay Sta ted
3. Condense On
4. Status LED On (continuous)
1. FAN mode On
2. BLOWER = LOW
3. Status LED On (continuous)
G Active?
Y Active?
LIMIT
Active?
FAN Mode
On?
G
Active?
W Active?
1. HEAT mode On
2. Blowe On-Delay Sta ted
3. Bu ne On
4. Status LED On (continuous)
Yes Yes
Yes
Yes
Yes
Yes
No No
No
No
No
No
Yes
No
1.BURNER Off
2. HEAT mode Off
3. BLOWER Off-Delay Sta ted
4. Status LED Off
HEAT
Mode On?
W
Active?
LIMIT
Active?
On-Delay
Ended?
Yes
Yes
Yes
Yes
No No No No