Carrier NDK33BN0KB, Operation & Service Manual

Page: 194 / 270

62-61753-21 7-78
Alarm
NO.
Steps ALARM / CAUSE CORRECTIVE ACTION
P188 CHECK HEATER 2 CIRCUIT (Continued)
460 VAC
CIRCUIT
6 Check Amp Draw of 1HTCON2 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 1HTCON2 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 Ohms Check from "T" terminals on HTCON2 contactor. See
Section 2.12 for correct Ohm ratings.
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.
9
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.