Loss of the Dimming Function of the Annunciator Lights

TASK 33-14-00-810-803-A
Loss of the Dimming Function of the Annunciator Lights

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 33-14-00-710-001	Operational Test of the Lights
ASM 331402
ASM 331403
AIPC 331408
AMM 33-14-51-000-001	Removal of the Essential Transformers
AMM 33-14-51-400-001	Installation of the Essential Transformers
Annunciator Light Test and Dimming

3. Fault Confirmation
Subtask 33-14-00-710-054-A

A. Test
(1) Do the operational test of the annunciator light test system AMM 33-14-00-710-001.

4. Fault Isolation
Subtask 33-14-00-810-057-A

A. If the dimming is not operative for all annunciator lights related to a same transformer

make sure that the INT LT/ANN LT switch (33LP) is in the DIM position.
make sure that there is 115VAC at pin A/B of the related transformer ASM 331403.

(1) If there is 115VAC

replace the related XFMR-ESS [31LP] or XFMR-ESS [35LP] or XFMR-SYS 2 [36LP] or XFMR-SYS 1 [37LP] AMM 33-14-51-000-001 and AMM 33-14-51-400-001.

(2) If there is no 115VAC

make sure that there is 28VDC between pins A/X1 and A/X2 of the related relay (38LP) or (39LP) or (41LP) or (42LP) ASM 331403.

(a) If there is 28VDC

replace the related RELAY-BRT/DIM, SYS 1 CTL (38LP) or RELAY-BRT/DIM, SYS 2 CTL (39LP) or RELAY-BRT/DIM, ESS CTL [41LP] or RELAY-BRT/DIM, ESS CTL [42LP] AIPC 331408.

1 If the fault continues

do a check and repair the wiring from the related relay, pin A/A1 to the related transformer pin A/B ASM 331403.

2 If the fault continues:

a If there is 28VDC:

replace the RELAY-ESS/EMERGENCY (40LP).
. If the fault continues:
do a check and repair the wiring between pin A/X1 and pin A/A1 of the relay (40LP).

b If there is no 28VDC:

do a check and repair the defective wiring of the relay (40LP) between:
. pin A/X2 and the ground terminal
. pin A/X1 and the first terminal block.

(b) If there is no 28VDC

do a check and repair the defective wiring from the relay
. pin A/X2 to the ground terminal
. pin A/X1 to the first terminal block ASM 331403.

Subtask 33-14-00-810-058-A

B. If the dimming is inoperative for all annunicator lights

(1) If there is 28VDC

do a check and repair the wiring from the pin 3A of the INT LT/ANN LT switch (33LP) to the first terminal block ASM 331403.

(2) If there is no 28VDC

(a) If the fault continues

do a check and repair the wiring from pin 1A of the INT LT/ANN LT switch (33LP) to the first terminal block ASM 331402.

Subtask 33-14-00-710-055-A

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:31:54 UTC