62-11785 7–50
P00189 CHECK EVAPORATOR FAN MOTOR - CONTINUED
460 VAC CIRCUIT
5. Check Amp Draw of 1EVCON Evaporator 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 2.9 for all three legs.
b. Check fuses F36, F37, and F38. Verify correct fuse, check fuse holder for damage, see Figure
2.3. Replace fuse as required. Clear alarms, restart and check for repeat alarm(s).
c. Check voltage at 1EVCON contacts. Must be within range shown in Section 2.9 for L1-L2, L1-L3,
and L2-L3. Must be within range shown in Section 2.9 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. Verify there is no visual physical
damage, no blockage to blower wheels, and they spin freely. Remove and replace if required.
b. With the unit off, check the resistance of the evaporator fan motor windings. See
Section 2.9
for
correct resistance. Resistance (Ohms) must be in range. No continuity from any high voltage lead to
ground.
7. Check Evaporator Fan Motor Connections - 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. Put microprocessor in PC Mode. Refer to Note 2 in Notes Section. Must have 0 AC1 Amps and 0
AC2 Amps in Unit Data.
b. Use a clamp- on ammeter to measure current draw of all 3 legs of the T side of PSCON/PSCON2.
Meter reading should be the same as Unit Data: Compare meter reading to Unit Data in PC Mode.
Compare meter reading to Unit Data with unit under load.
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