Service manual

7−88
62-11389
Alarm
NO.
Steps Alarm/Cause Corrective Action
P187 CHECK HEATER 1 CIRCUIT - Continued
460
VAC
CIR-
CUIT
6 Check Amp Draw of 1HTCON1 Heater Circuit
a. With the unit running and calling for
Heat, 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 heater elements. F10, F11, and F12 must not be blown.
c. Check voltage at 1HTCON1 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.
7 Check Heater Elements
a. Check heater elements with the unit
Off.
No visual physical damage.
Remove and replace if damaged.
b. Check heater element resistance. Check from “T” terminals on 1HTCON1 contactor.
See section 2.11 for correct resistance.
8 Check Heater Element Connections
a. Inspect high voltage heater con-
nections at evaporator.
No corrosion, water damage or burning /
discoloration.
Remove, repair, or replace if required.
b. Disconnect heater element plug. Heater resistance per Section 2.11.
Remove and replace heaters if required.
a. Inspect plugs, plug seal and con-
nectors.
No corrosion, water damage or burning /
discoloration.
Remove and replace if required.
9 Verify Accuracy of AC Current Sensor
Put microprocessor in PC Mode. Re-
fer to section 5.3 page 5−3.
Must have 0 AC1 Amps and 0 AC2 Amps in Unit
Data.