Carrier NDK33BN0KB, Operation & Service Manual

Page: 193 / 270

62-61753-21 7-77
Alarm
NO.
Steps ALARM / CAUSE CORRECTIVE ACTION
P188 CHECK HEATER 2 CIRCUIT
This device is checked twice in Pretrip - once in Test 2 and again in Test 8.

TRIGGER-ON TEST 2: Normal amps for the 1HTCON2 contactor coil are 0.05 to 2.0 Amps
(12 VDC). The circuit tests outside this range.

TRIGGER-ON TEST 8: Normal amps for the 1HTCON2 heaters are 1.0 to 3.5 Amps (460 VAC). The
circuit tests outside this range.

UNIT CONTROL: Engine and standby operation: Pretrip will fail and display "PRE-TRIP FAIL AND
COMPLETED".

RESET CONDITION: Auto Reset if Pretrip is started again, or alarm may be manually reset via key-
pad or by turning the unit off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, clear the
alarm(s). (
See Note 1 Page 7-1 ) Operate the unit through the appropriate modes to see if any active alarm oc-
curs. Continue with the steps below as necessary.
1 Determine Which Test Triggered This Alarm
a. Review active alarm list. Make a note of all alarms.
b. Clear active alarm list.
c. Restart and monitor Pretrip. Stop Pretrip during Test #3 by holding = Key for
6 seconds.
d. Review active alarm list for Alarm
188.
If alarm is present, follow steps 2 thru 4 If alarm is not
present, follow steps 5 thru 10.
12 VDC
CIRCUIT
2
Check 1HTCON2
a. Inspect heater contactor coil and
wire connections.
No damage to coil.
No damaged or corroded pins.
b. Check contactor coil resistance. Refer to Section 2.12.
3 Check 1HTCON2 Amp Draw
a. Check 1HTCON2 amp draw. Use Component Test Mode (Section 5.1.2) to test.
Refer to Section 2.12 for amp values. View current
draw in Data List.
4 Check 1HTCON2 Wiring
a. Inspect harness & control box
connector pins & terminals. (See
wiring schematic Section 10.)
See Note 2 & Note 5 on Page 7.2 .
No physical damage to harness.
No damaged or corroded pins.
5
Check Evaporator High Temperature Switch (EVHTS)
a. Inspect for open EVHTS per wiring
schematic Section 10.
If open, replace switch as required.
Additional steps on the next page.