Condensing Unit & Heat Pump R410A Service Manual
98
SERVICING
WARNING
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
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 connuity
to ground (pins to motor shell). If the ohmmeter indicates
connuity to ground, the motor is defecve and must be
replaced.
5. Using an ohmmeter, check the windings for connuity (pin
to pin). If no connuity 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 secon references the operaon characteriscs of the MBE/
AEPF models motor only. The ECM control board is factory
set with the dipswitch #4 in the “ON” posion and all other
dipswitches are factory set in the “OFF” posion. When MBE/
AEPF are used with 2-stage cooling units, dipswitch #4 should be
in the "OFF" posion.
The MBE/AEPF products use a General Electric ECMTM motor.
This motor provides many features not available on the
tradional PSC motor. These features include:
• Improved Eciency
• Constant CFM
• So Start and Stop
• Improved Humidity Control
MOTOR SPEED ADJUSTMENT
Each ECM™ blower motor has been preprogrammed for
operaon at 4 disnct airow levels when operang in Cooling/
Heat Pump mode or Electric Heat mode. These 4 disnct
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”
posion.
The MBE / aepf air handler motors have an electronic control
that contains an eight (8) posion dip switch. The funcon of
these dipswitches are shown in Table 1.
Dipswitch
Number
1
2
3 N/A
4 Indoor Thermostat
5 Cooling & Heat
6 Pump CFM
7
8
Function
Electric Heat
CFM Trim Adjust
Dipswitch Functions
Table 1
CFM Delivery
Tables 2, 3, 5 and 6 show the CFM output for dipswitch
combinaons 1-2, and 5-6.
Model Switch 1 Switch 2 CFM
OFF
OFF
1,200
ON
OFF
1,000
OFF
ON
800
ON ON 600
OFF
OFF
1,600
ON
OFF
1,400
OFF
ON
1,200
ON ON 1,000
OFF
OFF
2,000
ON OFF 1,800
OFF ON 1,600
ON ON 1,200
MBE1200
MBE1600
MBE2000
Electric Heat Operation
Table 2