Static Inverter Voltage and Frequency Indications Lost or Incorrect

TASK 24-28-00-810-803-A
Static Inverter Voltage and Frequency Indications Lost or Incorrect

1. Possible Causes

STAT INV [3XB]
BAT-1 [2PB1]
BAT-2 [2PB2]
C/B-EMER/GEN/REF [27WV]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242402
AMM 24-28-00-710-001	Operational Test of the Static Inverter when the Aircraft Electrical Circuits are Energized from the External Power
AMM 24-28-51-000-001	Removal of the Static Inverter
AMM 24-28-51-400-001	Installation of the Static Inverter
ASM 243501
AMM 24-38-51-000-001	Removal of the Batteries
AMM 24-38-51-400-001	Installation of the Batteries

3. Fault Confirmation
Subtask 24-28-00-865-050-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	SDAC/1/SPLY	3WV	F04
105VU	ELEC/STAT INV/CNTOR/CTL	14XB	G02
105VU	ELEC/STAT INV/BUS 901XP/SPLY	12XB	H02

Subtask 24-28-00-710-054-A

B. Test

do the operational test of the static inverter and the DC ESS BUS supply AMM 24-28-00-710-001.

4. Fault Isolation
Subtask 24-28-00-865-051-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
106VU	EMER/GEN/REF	27WV	B05
106VU	AC ESS/BUS/EMER/CNTOR/SPLY	15PC	C08

Subtask 24-28-00-810-056-A

B. If the test shows the voltage in amber and:
(1) The voltage is more than 120VAC:

replace the STAT INV [3XB] AMM 24-28-51-000-001 and AMM 24-28-51-400-001.

(2) The voltage is less than 110VAC:

do a check of the voltage of the batteries during the test.

(a) If the voltage is more than 22VDC:

replace the STAT INV [3XB] AMM 24-28-51-000-001 and AMM 24-28-51-400-001.

(b) If the voltage is less than 22VDC:

replace the BAT-1 [2PB1] and BAT-2 [2PB2] AMM 24-38-51-000-001 and AMM 24-38-51-400-001.

Subtask 24-28-00-810-057-A

C. If the test shows the frequency indication in amber:

replace the STAT INV [3XB] AMM 24-28-51-000-001 and AMM 24-28-51-400-001.

Subtask 24-28-00-810-058-B

D. If the test shows that amber crosses replace the voltage and frequency indications:

do a check of the status of the circuit breaker (27WV).

(1) If the circuit breaker is closed:

do a check for 115VAC at the pin 2 of the circuit breaker (27WV).

(a) If there is 115VAC:

do a check and repair the wiring between:
. the pin 2 of the circuit breaker (27WV) and the first branch point,
. the branch point and the pins AE/8B of the SDAC 1 (1WV1) and the SDAC 2 (1WV2) ASM 242402.

(b) If there is no 115VAC:

do a check and repair the wiring between the pin 1 of the circuit breaker (27WV) and the pin 1 of the circuit breaker AC ESS/BUS/EMER CNTOR/SPLY (15PC) ASM 243501.

(2) If the circuit breaker is open:

close it.

(a) Do a check of the wiring for a short to ground between the pin 2 of the circuit breaker (27WV) and the first branch point ASM 242402.
1 If the wiring is not correct:

repair it.

2 If the wiring is correct:

replace the C/B-EMER/GEN/REF [27WV] .

Subtask 24-28-00-710-055-A

E. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:44 UTC