GSZH5 Service Manual

81
SERVICING
1
2
3
4
5
Lines 1 and 2 will be connected
for 12OVAC Power Connector
applications only
Gnd
AC Line Connection
AC Line Connection
}
11
1 9
2
3
4
5
6
7
8 16
15
14
13
12
10
OUT - OUT +
ADJUST +/-
G (FAN)
Y1 Y/Y2
COOL
EM Ht/W2
DELAY
24 Vac (R)
COMMON2
HEAT
W/W1
BK/PWM (SPEED)
COMMON1 O (REV VALVE)
16-PIN ECM HARNESS CONNECTOR
If you do not read voltage and continuity as described, the
problem is in the control or interface board, but not the
motor. If you register voltage as described, the ECM power
head is defective and must be replaced.

WARNING





1. Disconnect the 5-pin and the 16-pin connectors from
the ECM power head.
2. Remove the 2 screws securing the ECM power head
and separate it from the motor.
3. Disconnect the 3-pin motor connector from the power
head and lay it aside.
4. Using an ohmmeter, check the motor windings for
continuity to ground (pins to motor shell). If the
ohmmeter indicates continuity to ground, the motor is
defective and must be replaced.
5. Using an ohmmeter, check the windings for continuity
(pin to pin). If no continuity is indicated, the thermal
limit (over load) device may be open. Allow motor to
cool and retest.
16-pin
connector
5-pin
connector
3-pin motor
connector

MBE Motor
This section references the operation characteristics of the
MBE/AEPF models motor only. The ECM control board is
factory set with the dipswitch #4 in the “ON” position and
all other dipswitches are factory set in the “OFF” position.
When MBE/AEPF are used with 2-stage cooling units,
dipswitch #4 should be in the “OFF” position.
For most applications, the settings are to be changed
according to the electric heat size and the outdoor unit
selection.
The MBE/AEPF products use a GE/Regal Beloit ECMTM
motor. This motor provides many features not available on
the traditional PSC motor. These features include:
•  󰀩
• Constant CFM
• Soft Start and Stop
• Improved Humidity Control
Motor Speed Adjustment
Each ECM™ blower motor has been preprogrammed for

Cooling/Heat Pump mode or Electric Heat mode. These 4
distinct levels may also be adjusted slightly lower or higher
if desired. The adjustment between levels and the trim
adjustments are made by changing the dipswitch(s) either
to an “OFF” or “ON” position.