Carrier NDK33BN0KB, Operation & Service Manual

Page: 196 / 270

62-61753-21 7-80
Alarm
NO.
Steps ALARM / CAUSE CORRECTIVE ACTION
P189 CHECK EVAPORATOR FAN MOTOR (Continued)
460 VAC
CIRCUIT
5 Check Amp Draw of 1EVCON Evap Fan Motor Circuit
a. With the unit running in either
HEAT or COOL use a clamp on
ammeter to check the current draw
of all 3 legs.
Must be within range shown in Section 2.11 for all
three legs.
b. Check fuses for evaporator fan
motor.
F18, F19, and F20 must not be blown.
c. Check voltage at 1EVCON con-
tacts.
Must be within range shown in Section 2.11 for L1-L2,
L1-L3, and L2-L3.
Must be within range shown in Section 2.11 for T1-T2,
T1-T3, and T2-T3.
6 Check Evaporator Fan Motor
a. With the unit off, visually check fan
motor and blower wheel.
No visual physical damage.
No blockage to blower wheels.
Blower wheels spin freely.
Remove and replace if required.
b. With the unit off, check the re-
sistance of the evaporator fan mo-
tor windings.
See Section 2.11 for correct resistance.
Resistance (Ohms) must be in range.
No continuity from any high voltage lead to ground.
7 CheckEvaporator Fan Motor Connections
a. Inspect high voltage fan motor
connections at evaporator.
No corrosion, water damage or burning / discoloration.
Remove, repair, or replace if required.
8 Verify Accuracy of AC Current Sensor
a. Place SROS in the OFF position .
Put microprocessor in PC Mode.
See Note 5 Page 7.2 .
Must have 0 AC1 Amps and 0 AC2 Amps in Unit Data
List.