Replacing The Motor Module; Testing The Motor; Motor Module Installation - Lennox EL180UHNE Series Unit Information

Replacing the Motor Module

1. Disconnect electrical power to unit.
2. Remove unit access panel.
3. Unplug the two harnesses from the motor control mod­
ule. See figure 13.
Unplug the Two Harness Connection
TWO HARNESS
CONNECTIONS
FIGURE 13
4. Remove the two hex head bolts securing the motor
control module to the motor (see figure 14).
Remove the Hex Head Bolts
REMOVE BOTH HEX
HEAD BOLTS
FIGURE 14
5. Slide the motor control module away from the motor to
access and disconnect the internal three wire connec­
tor. It is not necessary to remove blower motor itself.
Set both hex head bolts aside.
Testing the Motor (Figure15)
If any motor fails the below tests, do not install the new con­
trol module. The motor is defective and it also must be re­
placed. The new control can fail if placed on a defective mo­
tor.
1. Using an ohmmeter check the resistance from any one
of the motor connector pins to the aluminum end plate
of the motor. This resistance should be greater than
100k ohms.
2. Check the resistances between each of the three mo­
tor connector pins. These should all read approximate­
ly the same resistance within an ohm.
3. Check to see if the blower wheel spins freely.
MOTOR
MOTOR CONTROL MODULE
Measurement range in
Scale
words
two megohm-two million
2 M
ohms
two hundred kilo-ohm-two
200 K
hundred thousand ohms
twenty kilo-ohm-twenty
20 K
thousand ohms
two kilo-ohm two-thousand
2 K
ohms
200 two hundred ohms

Motor Module Installation

All replacement motor control modules look similar; how­
ever, each module is designed for a specific motor size. It is
very important to make sure that you are using the correct
replacement motor control module. USE OF THE WRONG
MOTOR CONTROL MODULE MAY RESULT IN UNEX­
PECTED UNIT OPERATION.
1. Verify electrical power to unit is disconnected.
2. Connect three-wire harness from motor to control
module.
3. Mount new motor control module
to motor using two hex head bolts
removed in figure 14. Torque bolts
to 22 inch pounds or 1/16
turn as exampled to the right.
4. Reconnect the two harnesses to
the motor control module.
5. The electrical connectors of the motor should be facing
down to form a drip loop (figure16). This will directs
moisture away from the motor and its electric connec­
tions on the motor.
BACK OF CONTROL
MODULE
Page 16
Motor Test
FIGURE 15
TABLE 8
ohms
0 - 2,000,000
0 - 200,000
0 - 20,000
0 - 2,000
0 - 200
11 12
10
th
clock
9
8
7
6
Drip Loop
CONNECTOR
ORIENTATION
BETWEEN 4 AND 8
O'CLOCK
DRIP LOOP
FIGURE 16
1/16
TURN
1
2
3
4
5