108
SERVICING
CONTROL CONNECTOR
"Motor Half“
(Viewed from connector end)
THERMOSTAT HEAT INPUT(S): R, W1, W2
First, low voltage readings are measured with the 16-pin wire
harness disconnected from the motor. A diagram of the har-
ness and pin locations is provided below. Voltage measure-
ment is AC or DC as specified in the chart below under the
(Volts) column. Set your voltage meter to the proper AC or
DC reading as requested below.
VARIABLE SPEED (ECM) MOTOR TEST
(High Stage Heat Call)
ECM Motor Not Coming On
In order for the heating fan speed to operate, the integrated
control board has to receive a low-stage (W1) and (W2) call
from the thermostat. The control board now starts the heat
sequence, bringing on the burners. After the control board
goes through its timing sequence, the following signals
should be seen at the end of the 16 pin harness going to the
motor while the burners are firing.
Unplug the 16-pin harness from the ECM motor. Set volt
meter to read AC volts. Place your voltage meter on Pin
1(Common) and Pin 2 (W1), you should be reading 13 AC
volts, if the (W2) is calling you should see 24 AC volts. Next,
check between Pin 1 (Common) and Pin 12 (R), you should
read 24 AC volts. Finally, check between Pin 1(Common)
and Pin 15 (G), you should read 13 AC Volts.
You MUST have all of these low voltage readings before the
ECM motor will come on. If you DO NOT have these read-
ings you may have a 16-pin wire harness or integrated con-
trol board problem.
Make sure you have high voltage at the 5-pin connector go-
ing to the motor as discussed earlier.
We highly recommend using the GE TECMate PRO™ model
ECM motor tester. This low cost test instrument will verify
whether the motor itself is good.
ADJUST +/-
Y 1
COOL
COMMON 2
COMMON 1
OUT +
EM HT/W2
24VAC (R)
BK/Pwm (Speed)
O (Rev Valve)
8
16
(1) This input must be active for motor to operate.
(2) 0 VAC indicates humidistat is calling for dehumidification.
(3) These two pins form an output circuit that powers the CFM LED on the ignition control or interface board.
(4) Dipswitch settings determine measure voltage.
(5) Voltage is measured with 16-wire harness disconnected from motor. Voltage measurement is AC or DC as specified in the chart.
Description Pin
Volts
(5)
Signal Indicates
Com, C1 1 0 VAC Common
W/W1 2
≥
13 VAC
W1 = ON
Com, C2 3 0 VAC Common
0 VAC Delay Tap = A
≥
10 VDC
Delay Tap = B
≤
-10 VDC
Delay Tap = C
24 VAC Delay Tap = D
0 VAC Cool Tap = A
≥
10 VDC
Cool Tap = B
≤
-10 VDC
Cool Tap = C
24 VAC Cool Tap = D
Y1 6 0 VAC Y1 = OFF
0 VAC Adjust Tap = A
≥
10 VDC
Adjust Tap = B
≤
-10 VDC
Adjust Tap = C
24 VAC Adjust Tap = D
Out -
(3)
8 0 VDC Common
O90 VACO = OFF
Bk/PWM
(2)
10 24 VAC No Dehumidification
0 VAC Heat Tap = A
≥
10 VDC
Heat Tap = B
≤
-10 VDC
Heat Tap = C
24 VAC Heat Tap = D
R 12 24 VAC R = ON
EM/W2 13 24 VAC EM/W2 = ON
Y/Y2 14 0 VAC Y/Y2 = OFF
G
(1)
15
≥
13 VAC
G = ON
Out +
(3)
16 0-3.5 VDC CFM LED
Thermostat Input(s): R, W1, W2
Delay
(4)
4
5
Cool
(4)
Adjust
(4)
7
11
Heat
(4)
To Next Page
Loading...
