electronically commutated motors

E l e c t r o n i c a l l yCommutated Motors

History 1977–1991

○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○

The

ory

of O

pera

tion

| E

CM

-1™

Mot

or

| E

CM

-2™

Mot

orE

CM

-2™

Tro

uble

Sho

oter

Kit

|

CT

M H

igh

Effi

cien

cy M

otor

5 W

ire

EC

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Out

door

Fan

Mot

or |

6

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1

Contents

Theory of Operation ............................................. 1ECM-1™ Motor ..................................................... 4

ECM-1™ Troubleshooting ..................................... 5ECM-2™ Inputs and Dip Switch Functions .......... 6

Quick Check Motor Will Not Run .......................... 16ECM-2™ Will Not Run ........................................... 21

Cooling Air Flow ................................................... 25

Heating Air Flow ................................................... 32Trouble Shooter Kit ............................................... 40

CTM High Efficiency Motor .................................. 445 Wire ECM™ Outdoor Fan Motor ....................... 52

6 Wire ECM™ Outdoor Fan Motor ....................... 626 Wire ECM™ Outdoor Fan Motor Troubleshooting 66

AC MOTOR THEORY

• Rotating Magnetic Fields

• Squirrel Cage Rotor - RequiresPower to create Magnetic Fields

• Efficiency - These type motorsefficency range from 35% - 50%Example: 50% per 1 HP powerrequired

WHAT IS ECM™?

Motor

• An Electronically Commutated Motor

• Three Phase Wound Stator

• Permanent Magnet Rotor

Theory of Operation

SQUIRREL CAGE

PERMANENT MAGNET

2

Theory of Operation

MOTOR SPEED• 2 Pole Motor • 4 Pole MotorPOLE DISTANCE = 180° POLE DISTANCE = 90°

1 CYCLE = 360° DISTANCE 1 CYCLE = 180° DISTANCE

• Frequency is measured in cycles per second, also called Hertz

• R.P.M. is measured in revolutions per minute

• Synchronous Motor R.P.M. =

• Motor Impedance is measured in OHMS and goes up as motor RPM goes up

• Motor Torque goes down as RPM goes up

• Synchronous Motor Torque is minimal

• Slip is the difference between synchronous motor RPM and Rated Motor RPM

• Maximum Current

• Motor Speed Varied by Changing Power and Frequency

AC Frequency in Hertz x 120Number of Poles in Motor

MOTOR CONTROL

• Motor Speed Is Controlled By The Drive Output Frequency

• Motor Torque Is Controlled For Specific Requirement By Varying Output Current

• Rotor Position and RPM Sensed By Motor Back EMF

• Performance and Efficiency Are Optimitized By Motor Drive

• Motor Is Protected Under Abnormal Load Conditions

3

Theory of Operation

VARIABLE SPEEDELECTRIC SYSTEM BLOCK DIAGRAM

The motor drive uses the latest technology inhigh current high voltage power switchingelectronics. The block diagrams show the powerfactor correction inductor, high frequency E.M.I.filter, full wave bridge rectifier, D.C. capacitor,microprocessor control circuit and the solid statepower switches for phase A, B and C.The power switches are drawn as mechanicalswitches for ease of explanation only. To showcurrent flow through motor, start at the powerswitch A and close its switch to the negativeterminal and close power Switch B to the positiveterminal and current can flow through two legs ofthe motor windings. Continue to open and closepower switches between their positive andnegative terminals to show how the motor statoris electrically commutated.

In actuality, there are periods of times in a three-phase cycle that the current will also be enteringtwo legs at the same time and leave through thethird leg.The time at which the switches are closed andopened to each entering leg is not the same.Remember, that current flows from negative topositive and current cannot flow in both directionsthrough any leg of the motor winding at the sametime. Three-phase current flow through the motorcan be simply explained this way.When in operation, the power electronic switcheswill be operated at different speeds to generate thefrequency (in Hertz) to cause the motor to run atdifferent speeds.

VARIABLE SPEED MOTORELECTRICAL SYSTEM BLOCK DIAGRAM

4

ECM-1™ Motor

ECM-1™

5

ECM-1™ Troubleshooting

VOLTS A/C

MOTOR LEADS

MOTOR

W1

W2

W3

B

O

R

Y1

Y2

BK

T

G

VOLTS A/C

1. Is there 24 V.A.C. betweenterminals “R” and “B” at airhandlers, or furnace?

YES: #2.

NO: Check 24 V.A.C. fuse and power to airhandler. Repair as required.

Possible component faults which could causefuse to blow.

Field wiring.Indoor fan relay.Thermostat.Switchover valve coil.O.D.S in the outdoor unit.

2. ECM-1™ to check for motor operation use jumper asfollows.

Step 1 Unhook field wiring from terminal board.Step 2 Jumper “R” to “G” and “BK”. Blower should

run at cooling high speed. black wire tap.Step 3 Jumper “R” to “G”. Blower should run at low

speed, white wire tap.Step 4 Jumper “R” to “G” and “W1”. Blower should

run at red wire heat speed tap.

Will motor run and change speed?

YES: Motor runs and changes speed, fault is in the fieldwiring or thermostat.

NO: If motor will not run, check all motor to terminalboard wiring. If wiring is OK, perform check No. 3.

ECM-1™

3. Check for power to the motor drive assembly,and can blower be freely spun. 115 V.A.C. forfurnaces. 230 V.A.C. for air handlers.

YES: If the voltage is correct and the blower willspin freely, replace motor and drive assembly.

NO: Restore power or free-up motor and checkfor proper operation.

6

ECM-2™ Inputs and Dip Switch Functions

ECM-2™

7


MOTOR CONTROL BOARDS

1 2 3 4 5 6 7 8ON

OFF

Y

CFMFAN

YOBKR G W1 W2 BLO

RETRO FIT KIT – CNT 1654 FURNACE – CNT 1537

PACKAGE UNIT BRD 0986

AIR HANDLER

ON

OFF

T R BK O Y G W1 W2 W3 B

R

B

CFM

FAN

Y LO

1 2 3 4 5 6 7 8 ON

OFF


B

R

CFM FAN

Y LO

1 2 3 4 5 6 7 8

J

BKJUMPER

CNT 1538 CNT 1866

CNT03600

8


The ECM™-2 motor is a Field ProgrammableMotor. The field programming is done with eightDip Switches on the motor control board. Themotor’s computer has eleven inputs and oneoutput. The eight Dip Switched and four of thecomputer inputs are used to program the coolingairflow, heating airflow and a time delay or rampcycle. The other seven inputs are used to turn themotor on or off, and command to run at aprogrammed CFM for heating or cooling. The oneoutput from the computer is used to turn thegreen CFM L.E.D. on and off on the motor controlboard. By counting the number of flashes theCFM program can be checked. Four differentinput commands can be sent to the motorcomputer with 24 V.A.C. by using the Dip switcheson the motor control board. 24 V.A.C. is suppliedto the motor computer for power and it is alsoused as a timing reference.

Dip Switch #2 will cause an in time command tobe received by the motor computer. The motorwill now run at it’s factory program for an intime command.

Dip Switches #1 and #2 closed will cause a doubletime command to be received by the motorcomputer, it will then run at it’s factory programfor a double time command.

1

2

B

24 VAC

R

D1

D2

2. DOUBLE COMMAND

ECM-2™ MOTOR MOTOR CONTROL BOARD

POWERTIME REFERENCE

1

2

B

24 VAC

R

D1

D2

1. IN TIME COMMAND


POWERTIME REFERENCE

1

2

B

24 VAC

R

D1

D2

3. OUT OF TIME COMMAND


POWERTIME REFERENCE

Dip Switch #1 closed will cause a out of timecommand to be received by the motor computer,it will then run at it’s factory program for a out oftime command.

When Dip Switch #1 and #2 are open nocommand will be received on this input by themotor computer, it will then run at it’s factoryprogram for a no command input.

1

2

B

24 VAC

R

D1

D2

4. NO COMMAND

POWER


TIME REFERENCE

9

ECM-2™ CONTROL INPUT


Air Flow Priority

The ECM-2™ motor will run at the called for CFM. If two or more calls are being received at the same time,G, Y and W1, for example a heat pump or cooling unit with an air handler, the ECM-2™ motor will run atthe highest speed call it is receiving, Y or W1.

A gas furnace ECM-2™ motor will run at the W1 or W2 airflow and will have priority over the " Y"airflow call.

TERMINAL PIN NO. FUNCTION

BK #10 Humidistat input for single, or two speed systems. Two speedsystem may be a two speed compressor or a two compressorsystem. If a humidistat is not installed, a jumper must be installedbetween “R” and “BK”. A XV 1500 variable speed system BK is theinput for the PWM blower speed command not humidistat.

W1 #2 CFM, blower speed, for low heat. Packaged Gas/Electric W1 andW2 are also used for a on or off command forthe motor. See Note: 1, 2 and 3 (on the next page).

W2 #13 CFM, blower speed for high heat. W2 on gas furnaces or W3 on airhandlers. Packaged Gas/Electric W2 is only blower on/offcommon. See Note: 1, 2 and 3 (on the next page).

G #15 On or off command for the motor. Air flow will be 50%of cooling Y CFM programmed.

YLO #6 CFM, blower speed, for low speed cooling on a two speedsystem, or two compressor system. See Note: 1, 2 and 3.

G1 #6 Package unit air flow will be 100 % cooling Y CFMprogrammed. G1 is only on Board #BRD0986.

Y #14 CFM, blower speed, for high speed cooling on a two speedsystem, or cooling CFM for a single speed system.

CFM #16 LED, will flash the number of times programmed by the Dipswitches in the cooling or heating cycle. Cooling CFM isprogrammed by Dip switches # 1 and # 2 tonnage times dipswitch # 3 and # 4 CFM per ton. Heating CFM is programmed byDip switches # 7 and # 8.

B #1, 3, & 8 Common 24 V.A.C.

O #9 Cooling cycle humidistat enable. Single or two speed systemonly. On a cooling system, “Y” must be jumpered to “O” forhumidistat operation.

R #12 Power and timing reference for ECM-2™ motor computer andpower to the Dip switches.

10


ECM-2™ CONTROL INPUT

Dip Switches

SWITCH PIN NO. FUNCTION

#1 & # 2 #5 Tonnage of outdoor unit. Package units these switches are notfunctional.

# 3 & # 4 #7 CFM per ton. 350, 400 or 450 CFM.

# 5 & # 6 #4 Are used to set up indoor blower time delay at the end of acooling cycle. If a delay or ramped on cycle is programmed, aheat pump or cooling only installation, the heating cycle bloweroff cycle will also be affected. The cooling air flow, CFM, will bereduced by 50%. A gas furnace or Package gas electric installa-tion, the ignition control will control the amount of time theblower is on at the end of the heating cycle. See ECM-2™ MotorOperation Chart for type equipment installed. On a variable speedsystem # 5 & # 6 must be in their off position.

# 7 & # 8 #11 CFM for low heat and high heat, 2 stage gas furnace or threestage electric heat. Package gas electric units these switches donot change heating air flow.

Note:

#1 YCZ050F: First stage heating or Cooling is 63% of second stage heating or cooling air flow.#2 YCZ036F: First stage heating or Cooling is 67% of second stage heating or cooling air flow.#3 YCZ060F: First stage heating or Cooling is 56% of second stage heating or cooling air flow.

11

RAMPED OPERATION – Dip Switch No. 5 andNo. 6 ON, works in both the cooling and heatingcycle. A call on “Y” and “G” is all that is needed toget a ramped ON and OFF cycle in either theheating or cooling cycle.COOLING HUMIDISTAT OPERATION – Will beenabled when a call on “O” is received by themotor computer. Cooling only units - a jumpermust be installed between “Y” an “O” at the MotorControl Board (ECMC™) plug. “BK” terminal isjumpered to “R” terminal on the Motor ControlBoard and this jumper must be cut to connect acooling humidistat.AIR FLOW PRIORITY is the highest speed call itis receiving, “Y” or “W”. If “Y” and “W” are bothturned ON at the same time (heat pumpoperation), the air flow will be the highest of thetwo and the “W” will cause the ramped ON cycleto be canceled.BLOWER TIME DELAY to OFF is controlled by theECM-2™ motor and Dip Switch No. 5 and No. 6 onthe (ECMC™) Motor Control Board. If a delay isprogrammed, 90 or 180 seconds, it will work inboth the heating and cooling cycles if the ECM-2™motor sees a call on “Y” and “G”. When theECM-2™ motor sees a call on “W” and “G”, thetime delay to OFF is canceled.FAN CONTINUOUS OPERATION – The airflow is50% of the cooling air flow. If cooling air flow isrequired for continuous fan operation, jumper G1pin to G pin at the (ECMC™) motor control boardplug. A factory installed jumper pigtail, (BK), isconnected to G1 pin for this purpose.

AIR HANDLERS BUILT BEFORE JUNE, 1994 –”O” is the ramp, on time delay and humidistatenable input.AIR HANDLERS BUILT AFTER MAY, 1994 – ”O"is needed only for the cooling humidistat enableinput.RAMPED OPERATION – Dip Switch No. 5 andNo. 6 ON, works in both the cooling and heatingcycle. A call on “0”, “Y” and “G” on air handlersbuilt before 6/94 or a call on “Y” and “G” on airhandlers built after 5194, is all that is needed to geta ramped ON and OFF cycle in either the heating orcooling cycle. If a cooling humidistat is notinstalled on air handlers built before June, 1994, ajumper must be installed between “R” and “BK”terminals.COOLING HUMIDISTAT OPERATION – Will beenabled when a call on “O” is received by themotor computer. Cooling only units – a jumpermust be installed between terminals “Y” and “O”at the Motor Control Board. When the humidity ishigh, the humidistat’s switch will be open and theblower air flow will be reduced 20%.AIR FLOW PRIORITY is the highest speed call itis receiving, “Y” or “W”. If “Y” and “W” are bothturned ON at the same time (heat pumpoperation), the air flow will be the highest of thetwo and the “W” will cause the ramped ON cycleto be cancelled. “W1” and “W3” are the heating airflow input terminals.BLOWER TIME DELAY to OFF is controlled by theECM-2™ motor and Dip Switch NO. 5 and No. 6 onthe Motor Control Board. If a delay isprogrammed, 90 or 180 seconds, it will work inboth the heating and cooling cycles if the ECM-2™motor sees a call on “Y” and “G”. When theECM-2™ motor sees a calls on “W” and “G”, thetime delay to OFF is cancelled.FAN CONTINUOUS OPERATION – The airflow is50% of the cooling airflow. If cooling air flow isrequired for continuous fan operation, removefield installed wires from “Y” terminal on the lowvoltage terminal board and wire nut themtogether. Then connect “G” terminal to “Y”terminal with a jumper.

100% IF NECESSARY

50%

80%

50%

OFFOFF

1 Minute

DEHUMIDIFYWARM AIR HEATING

FAST COIL COOLINGFAST COIL HEATING EFFICIENCY

7.5Minutes

3Minutes

HEAT PUMP & COOLINGPACKAGE UNIT

ECM-2™ MOTOR OPERATION

AIR HANDLER ECM-2™MOTOR OPERATION


12

BLOWER ON/OFF OPERATION, is “G”, “W1” or “W2”.RAMPED OPERATIONS, Dip Switch No. 5 andNo. 6 ON, will work in the Cooling Cycle Only.A call on “Y” and “G” together is all that isneeded to get a ramped ON and OFF cycle. Thismotor computer program is different from afurnace for it does not need “O” input to enablea ramped cycle.COOLING HUMIDISTAT OPERATION – “BK”terminal is jumpered to “R” terminal, at the(ECMC™) Motor Control Board #BRD0986CNT1866. This jumper must be cut to install acooling humidistat.HEATING AIR FLOW for W1 or W2, is the sameair flow as “YLO” or “Y” programmed. Switches#7 and #8 are not operational on these units.HEAT EXCHANGER COOL-DOWN CYCLE – Airflow will go to 50% of the cooling air flow. Theheating cool-down time is controlled by theignition module.COOLING CYCLE – Blower Time Delay to offis controlled by the ECM-2™ Motor and Dip SwitchNo. 5 and No. 6 on the (ECMC™) Motor ControlBoard. The ignition module cooling time delaydip switch must be set to O seconds if rampedoperation or a time-delay cycle is selected.FAN CONTINUOUS OPERATION – The airflowis 50% of the cooling air flow. If cooling air flow isrequired for continuous fan operation, jumperG1 pin and G pin at the (ECMC™) motor controlboard plug. A factory installed jumper pigtail,(BK), is connected to G1 pin for this purpose. Thisfactory jumper is only on motor control board#BRD00986

A Call on “Y” and “G” together. The indoorblower will run at 100%. “O” is the ramp, or timedelay and humidistat enable input. This “O” inputmust be received by the ECM-2™ Motor Computerfor these cycles to operate. Cooling only unitsjumper “Y” to “O” at the low voltage MotorControl Board.RAMPED OPERATION, Dip Switch No. 5 andNo. 6 ON, will work in the cooling cycle only. Acall on the “Y”, “G” and “O” together must bepresent for a ramped ON and OFF cycle. Ifa humidistat for cooling is not used, “BK” terminalmust be jumpered to “R” terminal. If not, only80% of the cooling airflow will be delivered.COOLING HUMIDISTAT OPERATION – “BK”and “R” terminals are connected to the humidistat.When the indoor humidity is high, the humidstat’sswitch will be open and the blower air flow will bereduced 20%.AIR FLOW PRIORITY is “W1” or “W2”, not thehighest air flow of “Y” or “W1” or “W2”. A DualFuel installation, a furnace and a heat pump,the airflow is compressor “Y” airflow exceptduring the defrost cycle. Then the blower willrun at W1 airflow when the furnace is on.COOLING CYCLE – Blower Time Delay to offis controlled by the ECM-2™ Motor and Dip SwitchNo. 5 and No. 6 on the Motor Control Board. TheWhite-Rodgers Ignition Control Dip Switch #1must be turned on, O seconds, when a rampedor time-delay cycle is selected.HEAT EXCHANGER COOL-DOWN CYCLE – Theair flow will go to 50% of the cooling air flow.Heating cool-down time is controlled by the White-Rodgers Ignition Control, Dip SwitchesNo. 2 and No. 3.FAN CONTINUOUS OPERATION – The air flowis 50% of the cooling air flow. If cooling air flow isrequired for continuous operation, removefield installed wires from “Y” terminal on thelow voltage terminal board and wire nutthem together. Then connect “G” terminal to“Y” terminal with a jumper.

DEHUMIDIFY

FAST COIL COOLING

100% IF NECESSARY

50%

80%

50%

OFFOFF

1 Minute

EFFICIENCY

7.5Minutes

3Minutes

PACKAGE GAS ELECTRICECM-2™ MOTOR OPERATION

FURNACE ECM-2™MOTOR OPERATION


13


FURNACE MOTOR CONTROL BOARD SCHEMATICCNT 1537

P2P2P2P2P2P2P2P2

D1

D2

D3

D4

D5

D6

D7

D8

1

2

3

4

5

6

7

8

BRW2W1OGYLOYBK

12345678

DIP SWITCHES

16 WIRECONNECTION

TO ECM

L1

L5

LED

L2 FAN

TERMINALBLOCK

LED N/C

D14 R3

R4 R1 R2C1

D9

FACTORY TEST PINS

TP1

TP2

TP3

TP5

FACTORY TEST PINS

TP6

TP4

TP7

CFMLED

L4

LEDL3

LED

SEEDIAGRAM

“A”

SEEDIAGRAM

“B”

P2P2P2P2P2P2P2P2

COMPUTER

TR

R B/C24 VAC IN

INTEGRATED FURNACE CONTROLTYPICAL CONNECTION

TH

12345678

DIAGRAM “B”

16 WIRECONNECTION TO ECM

DIAGRAM “A”

OD UNIT SIZEAIRFLOW ADJUSTOFF-DELAY OPTONSAUX HT. AIRFLOWCOMMONREFERENCECOMMONW1 CFMOG FAN ON/OFFYLO CFMY CFMBKW2 CFMCFM LIGHT -CFM LIGHT +

PI 5PI 7PI 4PI 11PI 1PI 12PI 3PI 2PI 9PI 15PI 6PI 14PI 10PI 13PI 8PI 16

W1 INW2 INGR OUTG OUTN.C.W2 CFM OUTB OUT

K2

K3 K1


1

8

From Dwg 21B860551

AIR HANDLER AND PACKAGE UNIT MOTOR CONTROLCNT03600

SEEDIAGRAM

“A”

14


AIR HANDLER MOTOR CONTROL BOARD SCHEMATICCNT 1538

P2P2P2P2

D1

D2

D3

D4

D5

D6

D7

D8

1

2

3

4

5

6

7

8

BRTW1OGYLOYBKW2W3

123J

DIP SWITCHES

16 WIRECONNECTION

TO ECM

L1

L5

LED

L2 FAN

TERMINALBLOCK

LED

D15 R3

R5

R2 R1

C1

D10

FACTORY TEST PINS

TP1

TP2

TP5

FACTORY TEST PINS

TP4

TP3

CFMLED

L4

LEDL3

LED

SEEDIAGRAM

“A”


DIAGRAM “A”

OD UNIT SIZEAIRFLOW ADJUSTOFF-DELAY OPTONSAUX HT. AIRFLOWCOMMONREFERENCECOMMONW1 CFMOG FAN ON/OFFYLO CFMY CFMBKW2 CFMCFM LIGHT -CFM LIGHT +

57411112329156141013816

+

57411112329156141013816

W1W2W4J – INTERLOCK

AUXILLARY HEAT CONNECTOR

K1

C2+ R4

N/C

K113 9

R6 C3R B

K1

1

16

D9

4 8

R4

D1

D2

D3

D4

D5

D6

D7

D8

1

2

3

4

5

6

7

8

BRTW1OGYLOYBKW2W3

DIP SWITCHES

16 WIRECONNECTION

TO ECM

L1

L5

LED

L2 FAN

TERMINALBLOCK

LED

D15 R3

R5

R2 R1

C1

D10

FACTORY TEST PINS

TP1

TP2

TP5

FACTORY TEST PINS

TP4

TP3

CFMLED

L4

LED

SEEDIAGRAM

“A”

57411112329156141013816

+

W2

AUXILLARY HEAT CONNECTOR

K1

C2+ R4

N/C

K113 9

R6 C3R B

K1

1

16

D9

4 8

R4

W1

J – INTERLOCK

W3

From Dwg 21B800338

CNT 1866

From Dwg 21B800338

15


From Dwg 21B664167

PACKAGE UNIT MOTOR CONTROL BOARD SCHEMATICBRD 0986

DS

J

D1

D2

D3

D4

D5

D6

D7

D8

1

2

3

4

5

6

7

8RBR

W1W1OGG1

Y

BK

W2W2

DIP SWITCHES

16 WIRECONNECTION

TO ECM

L1

5W

L2 FAN K14 8

G LED

R10

R5 C1

D10

D11R7

R9R8C4 K2

CFMLED

SEEDIAGRAM

"A"


DIAGRAM “A”

OD UNIT SIZEAIRFLOW ADJUSTOFF-DELAY OPTONSAUX HT. AIRFLOWCOMMONREFERENCECOMMONW1 CFMOG FAN ON/OFFY G1 CFMY CFMBKW2 CFMCFM LIGHT -CFM LIGHT +


K29

K21

8

K213

11

K113 9

R6 C3

D9R4

R1C2 K1

1

16


16

Quick Check Motor Will Not Run

ECM™’S CANNOT BETESTED UNLESSUNDER LOAD!

17


MOTOR CONTROL BOARDS

1 2 3 4 5 6 7 8ON

OFF

Y

CFMFAN

YOBKR G W1 W2 BLO

RETRO FIT KIT – CNT01654 FURNACE – CNT01537

AIR HANDLER

ON

OFF


R

B

CFM

FAN

Y LO

1 2 3 4 5 6 7 8 ON

OFF


B

R

CFM FAN

Y LO

1 2 3 4 5 6 7 8

J

BKJUMPER

CNT01538 CNT01866

PACKAGE UNIT BRD 0986CNT03600

18


ECM-2™ QUICK CHECKBlower Motor Will Not Run

These service procedures will work on ECM-2™ motors and their motor control board or a gasfurnace integrated Furnace Control IFC and their 16 Wire Low Voltage Control Cable. The gas furnace,IFC, will not turn on the ECM-2™ Blower Motor in the heating cycle until the burners have been onfor 45 seconds.

1. Jumper 24 V.A.C. “R”Terminal to “G” terminal onthe Low Voltage Terminalboard.

Does motor run?

NO: Go to step #2.

YES: Motor runs,check thermostatand thermostat wire.

2. Unplug 16 wire low voltage harnass from themotor control board. Jumper 24 V.A. C., topins #12, #15 and common pins #1 and #3.

Does the motor run?

NO: Go to step #3.YES: Replace themotor control boardon Air handlers, orPackage units.On Gas Furnaces, whichuse a CNT02223 furnaceignition control and a plugon the motor controlboard CNT01537, goto step #5. Furnaces withignition controls whichhave the motor controlbuilt in, replace thefurnace ignition control.

24 V.A.C.

19


3. Unplug 16 wire low voltage harness from the motor. Jumper 24 V.A.C. to motor low voltage plugpins #12 and #15 and pins #1 and #3 which are common.

Does motor run?

NO: Go to step #4.

YES: Fault is in the16 wire low voltageharness. Repair orreplace it.

4. Is the line voltage to the motor high voltage power plug pin #4 and pin #5 correct?

Furnace ECM-2™ motor correct voltage is 120 V.A.C. and there must be a jumper wire in this plugbetween pins #1 and #2.

Air handler ECM-2™ motor correct voltage is 220 V.A.C.

NO: Correct line voltage fault.

YES: Live voltage correct and themotor will not run. Check motorwinding resistance.ECM-2™ motor windings willread like a three phase motor.All three legs will readthe same resistance.If the motor is free to turnand the motor resistanceis correct then replace themotor module.

24 V.A.C.

20


Use these steps if the gas furnace uses a ignition control #CNT0223

5. Plug the 16 wire low voltage harness from the motor back into the motor control board. Jumper“G” in pin to “G” out pin of the White-Rodgers module which plugs into the low voltage motorcontrol board Does the motor run?

GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED

JUMPER TO W/R PINS“G” IN & “G” OUT

GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED

JUMPER TO PLUG “G” IN & “G” OUT

JUMPER FROMSTEP # 1

CNT01537

YES: Replace White-Rodgersignition module.

NO: Move the jumper to themetal part of the low voltagemotor control board plug.Does the motor run?

YES: White-Rodgers ignitionmodule pins not making contactwith motor control board plugs.Clean pins & plugs by unpluggingand plugging board onto pins orreplace both if necessary.

NO: Repair or replace the motorcontrol board.

CNT01537 MOTOR CONTROL BOARD

21

ECM-2™ Will Not Run

ECM™-2Blower Motor Will Not Run

1. Jumper “R” terminal to “G” on the motor control board Is the Fan Red LED on?

NO: Go to step #2.

YES: Go to step #5.

2. Is there 24 V.A.C. between terminal “R” and “B” on the motor control board?

NO: Check and repair as needed.Power to transformer, ortransformer or fuse.

YES: Go to step #3.

22


4. Is there 24 V.A.C. at the motor low voltage control pin #12, R timing reference and pin #1 common.NO: Check for 24 V.A.C. at the other end of the low voltage control wire harness at the motor controlboard plug at pins #12, R timer reference and pin #1 common. If voltage is not present, replace motorcontrol board, if 24 V.A.C. is present at this end of the harness fault is with the harness, repair orreplace.

YES: Go to step #5.

3. Is there 4.0 Volts D.C. at the motor low voltage control plug pin #15, G Fan On/Off, and pin #3common? If 7 to 8 Volts D.C. is read, check these low voltage control plug connections at the motor,if connections are O.K. Check motor winding resistance. ECM-2™ motor windings will read like athree phase motor. All three legs will read the same resistance. If the motor is free to turn and themotor resistance is correct then replace the motor module. “R” terminal to “G” still jumpered fromstep #1.

NO: Go to step #6 if 0 volts is read. If voltage is low, less than 3 volts D.C., unplug low voltage controlplug from the motor and again read the voltage between pin #15 and pin #3. If voltage now is 7 to 8volts D.C., replace the motor, if Voltage is still low go to step #6.

YES: Go to step # 4.

Check motor winding resistance. ECM-2™ motor windings will read like a three phase motor. All threelegs will read the same resistance. If the motor is free to turn and the motor resistance is correct thenreplace the motor module.

23


6. Unplug the 16 wire low voltage harness from the motor control board. Is there 7 to 8 Volts D.C. atthe motor control board plug between pin #15, G fan On/Off and pin #3 common? “R” terminal to“G” terminal still jumpered from step #1.

NO: Replace motor control board on an airhandler or package unit. If trouble shootinga furnace which uses a CNT02223 furnaceignition control and a plug on the motorcontrol board CNT01537 go to step #7.Furnaces with ignitioncontrols which havethe motor control boardbuilt in, replace thefurnace ignition control.

YES: Fault is in the16 wire low voltageharness or plugspin #15 or #3.

5. Is the line voltage to the motor high voltage power plug pin #4 and pin #5. correct?

Furnace ECM-2™ motor correct voltage is 120 V.A.C. and there must be a jumper wire in this plugbetween pins #1 and #2, Air handler ECM-2™ motor correct voltage is 220 V.A.C.

NO: Correct line voltage fault.

YES: Line voltage correct and motor willnot run, check motorwinding resistance. ECM-2™motor windings will readlike a three phase motor.All three legs will read thesame resistance. If themotor is free to turnand the motorresistance is correctthen replace themotor module.

24


7. Plug the 16 wire low voltage harness from the motor back into the motor control board. Jumper“G” in pin to “G” out pin of the White-Rodgers module which plugs into the low voltage motorcontrol board. Does the motor run?

YES: Replace White-Rodgers ignition module.


YES: White-Rodgers ignition modulepins not making contact with motorcontrol board plugs. Clean pins andplugs by unplugging and plugging boardonto pins or replace both if necessary.

NO: Leave this jumper in place and goback to step #6. If correct voltage is stillnot present repair or replace motorcontrol board. If correct voltage is nowread, fault is in 16 wire low voltage harness.

GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED


GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED

JUMPER FROMSTEP # 1

CNT01537


25

Cooling Air Flow

ECM-2™Correct Cooling Air Flow Can Not Be Obtained, Green CFM L.E.D.

Will Not Flash The Correct Number Of Times Programmed. Ramped(Enhanced) Cycle Turned Off Or Has Timed Out.

1. Is there 24 Volts A.C. between terminals “B” and “G” and “B” and “Y” at the low voltage motorcontrol board terminals? The red fan L.E.D. and red “Y” L.E.D. should be on. Package unit motorcontrol board #BRD0986 does not have a “Y” L.E.D. Motor control board #CNT03600 all L.E.D.s aregreen.

YES: Go to step #2 if thered “Y” L.E.D. is on.If the red “Y” L.E.D. isnot on, go to step #6.Package units go tostep #3.

NO: Fault is in thethermostat orthermostat wires.

26

Cooling Air Flow

2. Is the red “BK” L.E.D. on?Motor control boards CNT01654,CNT01537, and CNT01538 havea BK L.E.D. All other motorcontrol boards do not havea BK L.E.D. go to step #3.

YES: Go to #5.

NO: Go to #3.

YES: Go to step #4. If Humidistat operation or the ramped cycle does not work.

NO: If a humidistat is installed and it’s switch or it’s wiring is open, the cooling air flow will be reducedby 20%. If the outdoor unit is an air conditioner a jumper must be installed between “Y” and “O”terminals at the motor control board for humidistat or ramped cycle operation. Heat pump installation“O” from the thermostat must be connected to “O” terminal on the motor control board for humidistator ramped cycle operation. If a humidistat is not installed a jumper must be installed between “R” and“BK” terminal at the motor control board.

3. Is there 24 V.A.C. between terminals “B” and “BK” at the motor control board?

27

Cooling Air Flow

4. Is there +4 Volts D.C. between the motor low voltage control plug pin #10 humidistat input and pin#3 common? Motor control boards that do not have a BK L.E.D. this voltage will be 24 V.A.C.

YES: If air flow is low, go to step #6. If air flow is high (CFM will not go down when humidistat opens)or ramped cycle will not work, go to step #5.

NO: Is there +4 volts between the motor control board low voltage plug pin #10 and pin #3?

YES: Fault is in the 16 wire low voltage harness, repair or replace.

NO: Fault is in the motor control board, repair or replace the board.

��

��

��

��

��

��

28

5. Is there 24 V.A.C. between the motor low voltage control plug pin #9 (Humidistat or ramp cycleenable) and pin #3 common?

A Package Gas Electric unit: The voltage must be 0 V.A.C. at pin #9, for Humidistat or Ramp cycleoperation. Air Handler manufactured after 6-1994 will not need 24 V.A.C. at pin #9 for ramp cycleenable.

YES: If air flow, CFM, will not go down any when humidistat opens or ramped cycle will not work, andmotor low voltage control plug is clean and tight fitting, replace the motor module. If air flow, CFM, isincorrect, go to step #6.

NO: Is there 24 V.A.C. between the motor control board low voltage plug pin #9 and pin #3?


NO: Fault is in the motor control board, repair or replace.

Cooling Air Flow

24

VOLTS A.C.

24

VOLTS A.C.

CONNECT TO PIN #9

CONNECT TO PIN #3

CONNECT TO PIN #9

8 169

1

8 1

9

OFF

ON

T R BK O Y Y LO G W1 W2 W3 B

CFM

FAN

R

B

1 2 3 4 5 6 7 8

CONNECT TO PIN #3

29

Cooling Air Flow

6. Is there +4 Volts D.C. between the motor low voltage control plug pin # 14 (cooling blower speedand pin #3 common?

YES: Go to step #7.

NO: Is there +4 Volts D C between the motor control board low voltage plug pin #14 and pin #3?



30

Cooling Air Flow

7. Cooling air flow is programmed by dip switches number 1, 2, 3 and 4. Dip switches number 1 and 2are used to program the tonnage and are connected to the motor by wire #5. Dip switches number3 and 4 are used to set the CFM per ton and are connected to the motor by wire #7. 24 V.A.C. mustbe present at the motor control board terminals “R” and “B” for this test. Turn one switch on at atime and then off. If the correct voltage cannot be read at the low voltage motor control plug, thencheck for voltage out of the motor control board. If voltage is present at the output pins at themotor control board plug, fault is in the 16 wire low voltage control harness. If no voltage can beread at the output of the motor control board then the board is defective. If the voltages are correctat the low voltage motor control plug and the switches are set to their correct position and thegreen L.E.D. does not flash the required number of times go to step #8.

Switch #1 on +12 V.D.C. PIN #5 Switch #3 on +12 V.D.C. PIN #7Switch #2 on –12 V.D.C. PIN #5 Switch #4 on –12 V.D.C. PIN #7

24 V.A.C.

31

Cooling Air Flow

8. Is there any voltage, A.C. or D.C. present between terminal “B” and “W1” (W2 furnaces), (W 3 onair handlers) at the motor control board? If voltage is present, 1.5 volts or higher, the motor may bedelivering the heating airflow. Air handlers and Package heat pumps ECM-2™ motor will run at thehighest air flow requested, if two or more air flows are being requested at the same time. A GasFurnace unit, the ECM-2™ motor will run at the heating air flow requested, if two or more air floware being requested at the same time.

YES: Fault is in the thermostat or thermostat wiring.

NO: Replace the module.

32

Heating Air Flow

ECM-2™Correct Heating, W1 Or W2 Or W3 Airflow Cannot Be Obtained,

Green L.E.D. Will Not Flash The Correct Number Of TimesProgrammed. The Ramped (Enhanced) Cycle Is Turned Off By The

ECM-2™ When Ever It Receives A Call On W1 Or W2 On A GasFurnace Or A Package Gas Electric Unit Or A Call On

W1 Or W3 On An Air Handler.

1. Is the Low heat CFM Green L.E.D. flash rate correct?

YES: Go to Step #2.

NO: Go to Step #3.

33

Heating Air Flow

2. Is the High heat CFM Green L.E.D flash rate correct?

YES: If the Green CFM L.E.D. is flashing correctly but the motor is cutting off or airflow is low, checkthe total duct static. If total duct static is too high the motor may throttle back or cycle off.

NO: Is there 24 V.A.C. between terminals “B” and W2, on gas furnace or W3 on an air handler, at thelow voltage motor control board?

YES: Go to step #5.

Note 1: Packaged Gas Electric units may use W2 on some models and W3 on models that use a motorcontrol board CNT01866 or CNT0366.

PACKAGE GAS ELECTRIC: *Check the indoor blower relay “F-HI” and the ignition control modulefor 24 V.A. C. at it’s terminal HI Voltage should be present at this terminal approximately 30 secondsafter the burner has gone to high fire.

*Units that use a motor control board BRD0986, CNT01866, or CNT03600 check for 24 V.A.C. comingfrom the ignition control.

Fault is in the thermostat orthermostat wires.

NO: AIR HANDLERFURNACEPACKAGE HEAT PUMP

VOLTS A.C.

34

Heating Air Flow

3. Is there 24 V.A.C. between terminals “B” and “W1” at the low voltage motor control board?

YES: Go to step #4.

Fault is in the thermostat orthermostat wires.

NO: AIR HANDLERSFURNACEPACKAGE HEAT PUMP

PACKAGE GAS ELECTRIC: *Check the indoor blower relay “F-LO” and the ignitor control modulefor 24 Volts A.C. at it’s terminal LO. Voltage should be present at this terminal 45 seconds after ignitionhas been achieved.

*Units that use a motor control board BRD0986, CNT01866, or CNT03600 check for 24 V.A.C. comingfrom the ignition control.

35

Heating Air Flow

4. Is there 24 V.A.C. between the motor low voltage control plug pin #2 (Low heat blower speed) andpin #3 common?

YES: Go to step #2 if problem is with high heat airflow. If problem is with low heat airflow, go tostep #6.




36

Heating Air Flow

5. Is their 24 V.A.C. between the motor low voltage control plug pin #13 (high heat blower speed) andpin #1 common?

YES: Go to step #6.



Fault is in the motor control board,repair or replace.

NO: AIR HANDLERPACKAGE HEAT PUMPPACKAGE GAS ELECTRIC

VOLTS A.C.

VOLTS A.C.

Furnaces that use a CNT02223 furnace ignition control and a plug on the motor control boardCNT01537 go to step #8. Furnaces with ignition controls which have the motor control built in,replace the furnace ignition control.

37

Heating Air Flow

6. Heating air flow is programmed by dip switches number 7 and 8. Dip switches number 7 and 8 areconnected to the motor by wire #11 24 V.A.C. must be present at the motor control board terminals“R” and “B” for this test. Turn one switch on at a time and then off. If the correct voltage cannot beread at the low voltage motor control plug then check for voltage out of the motor control board. Ifvoltage is present at the output pins at the motor control board plug, fault is in the 16 wire lowvoltage control harness. If no voltage can be read at the output of the motor control board then theboard is defective. If the voltages are correct at the low voltage motor control plug and theswitches are set to their correct position and the green L.E.D. does not flash the required number oftimes go to step #7.

Switch #7 on +12 V.D.C. PIN #11

Switch #8 on –12 V.D.C. PIN #11

Note 1: Package Gas Electric Units dip switches number 7 and 8 do not change the heating airflow.These units’ airflow for heating and cooling are the same.

24 V.A.C.

38

Heating Air Flow

7. Is there any voltage, A.C. or D.C. present between terminal “B” and “YLO” “B” and “Y” at themotor control board? If voltage is present, 1.5 volts or higher, the motor may be delivering thecooling airflow. Air handlers and package heat pumps the ECM-2™ motor will run at the highest airflow requested, if two or more air flow are being requested at the same time. A Gas Furnace unit,the ECM-2™ motor will run at the highest heating air flow requested not the highest air flowrequested if two or more air flow are being requested at the same time.

YES: Fault is in the thermostat or thermostat wiring.

NO: Check motor winding resistance. ECM-2™ motor windings will read like a three phase motor. Allthree legs will read the same resistance. If the motor is free to turn and the motor resistance is correctthen replace the motor module.

Note 1: With Packaged Gas Electric Units the heating airflow is the same as the cooling airflow.

39

Heating Air Flow

8. Plug the 16 wire low voltage harness from the motor back into the motor control board. Jumper“G” in pin to “G” out pin of the White-Rodgers module which plugs into the low voltage motorcontrol board. Does the motor run?

YES: Replace White-Rodgers ignition module.


YES: White-Rodgers ignition modulepins not making contact with motorcontrol board plugs. Clean pins andplugs by unplugging and plugging boardonto pins or replace both if necessary.

NO: Leave this jumper in place and goback to step #6. If correct voltage is stillnot present repair or replace motorcontrol board. If correct voltage is nowread, fault is in 16 wire low voltage harness.

GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED


GINW2W1

ROUT

GOUT

W2CFM

BOUT

NOT USED

JUMPER FROMSTEP # 1

CNT01537


40

Trouble Shooter Kit

TROUBLESHOOTING ECM-2™ MOTORWITH TROUBLESHOOTING CIRCUIT BOARD

AND 4 WIRE TEST CABLE

ECM-2™ TROUBLESHOOTER KITOrder Pub. No. 34-3403-01

Purpose: Verify proper signals are being received by the motor control board and are beingsent to the ECM-2™ Motor by the 16 wire low voltage motor harness.

1. Turn power off2. Disconnect all low voltage field wiring,

set all dip switches to “OFF”.3. Disconnect the 16-pin connector at the

ECM-2™ Motor. Plug in the “Troubleshooter”to the harness.

4. Turn on power.5. The troubleshooter “R” L.E.D. on the board

should be on.6. If the troubleshooter “R” L.E.D. is not

on, check for 24 volts A.C. at the motorcontrol board.

7. If 24 volts A.C. is not present, troubleshootand repair as needed.

8. If 24 volts A.C. is present, check the trouble-shooter “R” L.E.D. and check continuity of the16 wire cable, pin 1 to pin 1, through pin 16. Iftroubleshooter “R” L.E.D. is good and 16 wirecable pin #1 and pin #12 are good, repair orreplace motor control board.

9. The green “C.F.M.” L.E.D.’s should beflashing on the motor control board andtroubleshooting board. If the green CFML.E.D. on the motor control board does notflash, check the troubleshooter “CFM” L.E.D.and continuity of the 16 wire harness, pin #8and #16. If troubleshooter “CFM” L.E.D.and harness are good, replace motorcontrol board.

41

Trouble Shooter Kit

Dip Switch Operation

10. In order, turn on dip-switches 1 through 8,one at a time.

11. Verify that the corresponding L.E.D. on thetroubleshooter is being turned on: Dip switch1 on, L.E.D. DS-1 is on.

12. Turn off dip switches 1 through 8 and verifyeach LED goes off.

13. If the correct L.E.D.’s do not turn on and off inthe proper sequence, check continuity of the16 wire harness with ohmmeter: pin 1 goesto pin 1, pin 2 to pin 2, etc. through pin 16. Ifharness is good, replace motor controlboard. If harness is bad, repair or replace.

Low Voltage Thermostat Operation

14. Verify thermostat signals by jumping“R” to each of the low voltage terminalconnections, on a package unit use the wirenut connectors, as follows: BK, O, Y YLO, G,W1, W2, W3. See exceptions below for airhandlers, furnaces, package gas electric orretro fit motor control boards. Thecorresponding L.E.D. on the troubleshootershould light when “R” is applied. VerifyL.E.D.’s on motor control board lightaccording to the applied signal: BK, Y YLO,fan. If L.E.D. on motor control board does notlight and 16 wire harness is good, replaceboard.

Furnace

W2 will not light W2 L.E.D. on the troubleshooterdue to White-Rodgers ignition control’s normallyopen switch.Package Gas Electric Units

Package gas electric units L.E.D. W1 andW2 will not light due to the ignition control nor-

mally open switch. Jumper at the motor controlboard plug, pin W1 and W2, should cause L.E.D.’son troubleshooter to light.If L.E.D. Y LO comes on when R to G is jumperedfactory jumper 47B, G2 terminalto G terminal, has been connected. L.E.D.BK will come on when power is appliedunless cooling humidistat is installed andit’s switch is open.Air Handler

Air handler W2 terminal board does not lightL.E.D. W2 on the troubleshooter air handler – W3terminal does.Retro Fit Motor Control Board

Retro fit motor control board W2 is notconnected and will not light W2 ontroubleshooter.Package – Heat Pump or CoolingUnits

If L.E.D. Y LO comes on when R to G is jumperedfactory jumper 47B, G2 terminalto G terminal, has been connected. L.E.D.BK will come on when power is appliedunless cooling humidistat is installed andit’s switch is open.

42

Trouble Shooter Kit – Check L.E.D.s

To Test Jumper 24 V.A.C. ToL.E.D. No. Pin No & Pin No. Operation

DS-1 5 1 Both L.E.D. ON

DS-2

DS-3 7 1 Both L.E.D. ONDS-4

DS-5 4 1 Both L.E.D. ONDS-6

DS-7 11 1 Both L.E.D. ON

DS-8

R 12 1 R L.E.D. ON

W2/W3 13 1 W2/W3 L.E.D. ON

W1 2 3 W1 L.E.D. ON

O 9 3 O L.E.D. ON

G 15 3 G L.E.D. ON

YLO 6 3 YLO L.E.D. ON

BK 10 3 BK L.E.D. ONY 14 3 Y L.E.D. ON

CFM 16 8 CFM L.E.D.Flash ON/OFF

Jumper 24 V.A.C. to the following Pin Numbers:

9 10 11 12 13 14 15 161 2 3 4 5 6 7 8

End view of Socket on TroubleshooterEnd view of Socket on Trouble Shooter

43

Trouble Shooter Kit

1. Disconnect power to unit.2. Remove 16 pin connection from ECM-2™ motor.3. Plug in 16 pin connector “4 wire test”

cable to ECM-2™ motor.4. Check power plug at motor and

verify that it is installed andproperly seated.

5. Connect Red wire to “R” atmotor control board.

6. Connect Blue wire to “B” atmotor control board.

TROUBLESHOOTING WITH“4 – WIRE TEST” CABLE – GO/NO GO

1. Turn on power to unit.2. Motor should come on and

run continuous fan speed.3. If motor does not run, verify

24 V.A.C. is present betweenR & B. If 24 V. A.C. or correct linevoltage is not present,troubleshoot and repair as needed.

Furnace ECM-2™ motor correct voltage is 120 V.A.C. and there must be a jumper wirein this plug between pins #1 and #2.

Air handler ECM-2™ motor correct voltage is 220 V.A.C.

44

CTM High Efficiency Motor

CTM

45

The CTM High Efficiency Motor is part of the General Electric ECM™Motor Products offering using ECM™ technology without its full matrixof programming and control options. The airflow characteristics aresimilar to a PSC motor. As static increases, air flow goes down. As rpmincreases, amperage goes down. The motor is controlled by usingpre-programmed 24 V.A.C. input taps. Taps 1 through 4 are alwaysprogrammed.

The CTM High Efficiency Motor has many of the same features as theECM-2™ Variable Speed. Features like (1) a Brushless DC motor/perma-nent magnet rotor, (2) the same power conversions in the control mod-ule (Creates three-phase voltage from single phase line voltage), (3) thesame efficiency as the ECM-2™, (4) is programmed for each unit appli-cation, and (5) has soft (controlled) starting.

The CTM High Efficiency Motor also has several unique features. Mostimportantly, the motor focuses on maintaining a constant torque via thecontrol module which is optimized around providing constant torque.Because the motor does not have the same flexibility of the VariableSpeed motor, a simpler interface is used.


The CTM High Efficiency Motor has 2 major components:

• A three phase permanent magnet rotor motor.• Power control module.

46


Connections – Line Voltage - 3/16” x 0.020 male Quick Connect terminalsGas Furnaces – 120 V.A.C. (L = Line, G = Ground, N = Neutral)Air Handlers – 230 V.A.C. (L = Line 1, G = Ground, N = L2) G not used, end bell ground is used.

Line Voltage Connections

Low Voltage Connections

Connections – Low Voltage - 1/4” x 0.036 male Quick Connect terminalsC = 24 V.A.C. Common1 = 24 V.A.C. input (always programmed) 4 = 24 V.A.C. input2 = 24 V.A.C. input 5 = 24 V.A.C. input3 = 24 V.A.C. input

*Note – terminals are programmed for each unit application. Each program is unique and may not re-quire the use of all 5 terminals. Taps 1 through 4 are always programmed. When 24 V.A.C. is applied toan un-programmed tap no rotation will occur.

47


*Note - when 24 V.A.C. is applied to an un-programmed tap no rotation will occur.Presently, the motor and control modules are not available separately. If motor assembly is replacedunder warranty, return complete assembly.

Apply Correct Line Voltage to motor terminals "L" and "N". 24 V.A.C. should be applied to Tap 1 andCommon (C). Tap 1 is always programmed. 24 V.A.C. can also be applied to the other speed taps if de-sired, one at a time.Note: Speed tap 5 does not operate on all motors.If motor does not operate, order a replacement.

TROUBLESHOOTINGMotor and Module as one piece only

120 V.A.C.or

240 V.A.C.

24 V.A.C.

48


COOLING OFF DELAY OPTIONAIR HANDLERS AND FURNACES

This option allows the indoor fan to continue to run for a short time after the outdoor unit shuts off forincreased cooling efficiency.

AIR HANDLERSELECTRONIC TIME DELAY RELAY (ETDR)

Air Handlers with the CTM High Efficiency Motor utilize a solid state control board called an ETDR.The ETDR is a 45 second timed-off delay control board. The control board uses a double pole-doublethrow relay (K1).

The K1 relay controls two outputs through the normally open contacts (N.O.);The J Circuit - electric heat interlock, and24 V.A.C. G output to the CTM High Efficiency Motor.

49


To enable the Timed-off Delay,Disconnect T3 wire from G circuitConnect T3 wire to R circuit as shown inFigure 2.

When thermostat G demand is removed from T7,the T3 terminal remains energized enabling the 45second timed-off delay circuit. Relay K1 will stayenergized allowing motor to operate for 45 sec-onds.

Refer to unit diagram for complete unit wiring.

From the Factory, the ETDR is wiredso the delay option is not active.When voltage is applied to T3 and T7,from the thermostat G terminal, theK1 normally open contacts close en-ergizing the J Circuit and 24 V.A.C.output to the motor. When the ther-mostat G demand is removed, the K1contacts open de-energizing both cir-cuits. See Figure 1.

Figure 2

Figure 1

50


TYPICAL AIR HANDLER WIRING DIAGRAM

51


TYPICAL FURNACE WIRING DIAGRAM

Furnaces with the CTM High Efficiency Motor utilize the Integrated Furnace Control (IFC). The IFC isshipped from the factory with the Cooling Off Delay set to “0” seconds, the switch (S-1, SW1) in the“ON” position. To activate the 0 second fan Off Delay option, move the switch to the “OFF” position.Refer to the diagram on unit for switch location.

52

5 Wire ECM™ Outdoor Fan Motor

5 WIRE ECM™

53


TROUBLESHOOTING

1. Fan motor will not run.Use Chart # 1.

2. Fan will not change speeds or is running at the wrong speed.Use Chart # 2.

3. Fan motor is changing speeds up and down and the fanthermostat is not switching back and forth.Go to Chart # 1, Step # 5.

54


CHART #1ECM™ Outdoor Fan Motor Will Not Run

2. Caution – line voltage isnot switched by the contactor. Check linevoltage to motor brown and black wires.Is the correct line voltage present?

NO: Repair as needed.YES: Go to Step #3.

1. Is the motor shaft free?NO: Free up motor or replace.YES: Go to Step #2.

55


3. Is there 24 V.A.C. present between pins Y and B on thefan control board?

NO: Is the compressor contactor picked up?If not, repair as needed.YES: Go to Step #4.

4. Is the red L.E.D. on the fan controlboard on?

NO: Outdoor fan thermostat is in the hot position orthe L.E.D. circuit on the fan control board has failed.D.C. voltage in Steps #5 and #6 shouldbe 16 – 24 V. D.C.Go to step #5.YES: Outdoor fan thermostat isin the cold position.D.C. voltage in Steps #5 and #6should be 8 – 12 V. D.C.Go to Step #5.

56


5. Is the correct D.C. voltage present betweenterminals A and C on the fan control board?

NO: Replace fan control board.YES: Go to Step #6.

6. Is the correct D.C. voltagepresent between the blue andyellow motor leads?

NO: Repair motor plug orwires going to the fan controlboard terminals A and C.YES: Replace motor.

VOLTS D.C.

VOLTS D.C.

57


CHART #2ECM™ Outdoor Fan Motor Will Not Change Speeds

1. Outdoor fan motor must be running for thetest. Is the red L.E.D. on the fan controlboard on?

NO: Outdoor fan thermostat is in the hot posi-tion, or has failed, or the L.E.D. circuit on the fancontrol board has failed. Go to Step #4.YES: Outdoor fan thermostat is inthe cold position switch closed.Go to Step #2.

2. Take one of the wires off the outdoor fanthermostat. The red L.E.D. on the fan controlboard will go out. Does the outdoor fanmotor go to high speed?

NO: If the red L.E.D. is still on, fault is in theunit’s wiring going to the fan control board. If thered L.E.D. is out, Go to Step #3.YES: Check the outdoor fan thermostat forproper operation.

58

3. Read the D.C. voltage between terminalsA and C on the fan control board.Plug the wire removed from thethermostat in Step #2 back on theoutdoor fan thermostat.The red L.E.D. must come on again,if not jumper both wires together on theoutdoor fan thermostat. Again, readthe D.C. voltage between terminalsA and C on the motor control board.Did the D.C. voltage drop to about half?

NO: Replace motor control board.YES: Replace the outdoor fan motor.


59


4. Jumper the two wires together on the outdoor fanthermostat. Does the red L.E.D.on the fan control board come on?

NO: Check for 24 V. A.C. between terminals T2 and B on thefan control board. If 24 V. A.C. is present and the L.E.D.is out, replace the fan control board. If 24 V. A.C. is notpresent at terminals T2 and B, fault is in the unit’s wiring.YES: If the outdoor fan motor changes speed, check the out-door fan thermostat for proper operation. If the outdoor fanmotor does not change speed, go to Step #5.

VOLTS A.C.

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5. Read the D.C. voltage betweenterminals A and C on the fan control board,record this voltage. Remove the jumperinstalled in Step #4 on the outdoor fanthermostat. Again read the D.C. voltagebetween terminals A and C on the fancontrol board. Is the D.C. voltage nowabout double the recorded voltage?

NO: Replace fan control board.YES: Replace fan motor.


61


OUTDOOR ECM™ FAN MOTOR CONTROL BOARD

62


6 WIRE

63


The 6 wire variable speed outdoor fan motor is used on the high efficiency heat pumps and coolingunits. These motors are two speed ECM motors. They can be turned on /off and the speed changedfrom high to low or low to high using either a 24 V.A.C. signal or a PWM D.C. call signal

Cooling models the variable speedoutdoor fan motor speed is controlledby the outdoor thermostat ODT-A andthe 24 V.A.C. Y call from the system’s In-door thermostat.

The motor is turned on when 24 V.A.C signal from the indoor thermostat is applied to the motor’s yel-low wire. The motor will now run at high speed. During motor operation 24 V.A.C. is applied to the yel-low wire at all times. The motor’s blue wire is connected to the 24 V.A.C. common.

64


The outdoor thermostat ODT-A switches themotor from high to low speed by applying anadditional 24 V.A.C. to the motor’s white wire.The outdoor thermostat ODT-A switches at 76degrees F to low speed and will switch backto high speed at 80 degrees F.

Heat Pump models the variable speedoutdoor fan motor is turned on and its speedis controlled by the units defrost control. Thedefrost control has an output terminal whichsends a Pulse Width Modulation, PWM,signal to the variable speed outdoor fanmotor. The PWM signal is applied to themotor’s yellow wire. The motor will turn onwhen it sees a PWM signal.

ODT

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This PWM signal is D.C. and can be read with a standard Volt Ohm Meter set to the DC Voltage posi-tion. The motor’s blue wire is connected to the 24 V.A.C. common which is also the D.C. common. Thehigh speed signal is a 79% PWM signal and it will read approximately 15 V.D.C...The low speed signal is a 29% PWM signal and it will read approximately 6 V.D.C.

66

6 Wire ECM™ Outdoor Fan Motor Troubleshooting

Caution: All models of variable speed outdoor fanmotors have High Voltage power applied to themwhen the outdoor unit’s disconnect is turned on.

1. Ensure that the motor shaft turns freely.Keep in mind that the variable speed motorwill have a different feeling from a standardball bearing motor.

2. Check the line voltage being applied to themotor, check it past the motor polarizedplug. Voltage should be + or – 10% of thename plate voltage.

Motor turns freely

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3. Connect 24 V.A.C. to the ECM motor’s low voltage yellow wire and its blue wire on the motor sideof its polarized plug. When you have low voltage and high voltage to the motor it should start andrun. Does the motor start and run.

YES: Go to step # 4 if this unit is switching the motor speed from high to low speed with 24 V.A.C. Ifthe unit is a heat pump, the motor is okay. The defrost control should be supplying a PWM D.C. volt-age call to the motor the motor. Check the defrost control for the PWM D.C. voltage call. See pages 63& 64 for details.NO: Replace motor

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4. Disconnect the 24 V.A.C. from the motor’s low voltage yellow wire. The motor will now stop. Nowconnect together the 24 V.A.C. to the motor’s low voltage yellow wire and the motors low voltagewhite wire, the 24 V.A.C. common still connected to the motor’s blue wire. Does the motor nowstart and run at low speed?

YES: Motor is ok, check the units ODT-A for a 24 V.A.C. call. Heat pumps that have a defrost controlwhich supplies a PWM D.C. call signal do not use the motor’s white low voltage wire.NO: Replace motor.


Note: 6 Wire White Wire notused when a PWM D.C.call is used.

Note: On Heat Pump Models only-5 wireswill be used between the controlbox and the motor plug.

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Literature Order Number

File No. Pub. No. 34-3402-04 3/06

Supersedes Pub. No. 34-3402-03 1/03

Stocking location PI

P.O. Box 9010Tyler TX 75711-9010http://www.trane.com

Since Trane has a policy of continuous product improvement, it reserves the right to change design andspecifications without notice.© 2006 American Standard All rights reserved

A Business of American StandardCompanies.

electronically commutated motors

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