(b)  
GRD PWR switch

(2)  
When the No. 1 generator control unit (GCU) is changed start engine No. 1. When the No. 2 GCU is changed start engine No. 2. (AMM 71-09-100/201).

(3)  
On the P5-13 panel, put the AC meter selector switch to the GEN position of the GCU being tested. Make sure the following indications are shown:

(a)  
The AC VOLTS meter shows 0 volts.

(b)  
The AC FREQ shows 0 Hz.

(4)  
On the P5-5 panel, make sure the following lights are OFF:

(a)  
LOW OIL PRESSURE

(b)  
HIGH OIL TEMP

(5)
On the P5-4 panel, put the GEN switch of the GCU being tested to ON then OFF.

(6)
On the P5-13 panel, push the RESID VOLTS switch, make sure the following is shown:

(a)  AC voltmeter shows 10 to 21 volts.

(7)  
On the P5-4 panel, make sure the following lights are ON:

(a)  
TRANSFER BUS OFF

(b)  
BUS OFF

(c)  
GEN OFF BUS

(8)  
On the P5-4 panel, put the GEN switch of the GCU tested to ON. Make sure the following lights for the generator being tested are OFF:

(a)  
TRANSFER BUS OFF

(b)  
BUS OFF

(c)  
GEN OFF BUS

(9)  
On the P5-13 panel, make sure the following is shown:

(a)  
AC voltmeter shows 115 ±5 volts.

(b)  
Frequency meter shows 400 ±5 Hz.

(10)
On the P5-4 panel, put the BUS TRANS switch to AUTO, make sure the following lights are OFF:

(a)
Left and right TRANSFER BUS OFF

(b)
Left and right BUS OFF

NOTE: Voltage indicates the control (field) relay has closed.
544 
May 01/99  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  24-21-81 Page 401 

NOTE: The GEN OFF BUS light will remain ON for the engine not being tested.
(11) On the P5-13 panel, make sure the following is shown:
(a)
AC voltmeter shows 115 ±5 volts.

(b)
Frequency meter shows 400 ±5 Hz.

B. Airplanes without electrical load shedding, do the following:
(1)
On the P5-8 panel, put the HYD PUMPS B ELEC 1 and 2 switches ON.

(2)
On the P5-8 panel, make sure the LOW PRESSURE lights are OFF.

(3)
On the P5-13 panel, make sure the following is shown:

(a)
AC voltmeter shows 115 ±5 volts

(b)
Frequency meter shows 400 ±5 Hz.

(4)
On the P5-4 panel, make sure the AC AMPERES shows a current.

(5)
On the P5-5 panel, make sure the following lights for the GCU being tested are OFF:

(a)
LOW OIL PRESSURE

(b)
HIGH OIL TEMP

(6)
Restore airplane to normal.

C. Airplanes with electrical load shedding, on the P5-8 panel, do the following for the GCU tested:
(1)
Put the HYD PUMPS B ELEC switch for the GCU being tested to ON.

(a)
If the No. 1 GCU is tested, put the HYD PUMPS B ELEC 1 switch to ON.

(b)
If the No. 2 GCU is tested, put the HYD PUMPS B ELEC 2 switch to ON.

(2)
Make sure the LOW PRESSURE light is OFF.

(a)
If the No. 1 GCU is tested, the left LOW PRESSURE light is OFF.

(b)
If the No. 2 GCU is tested, the right LOW PRESSURE light is OFF.

(3)
On the P5-5 panel, make sure the following lights are OFF:

(a)
LOW OIL PRESSURE

(b)
HIGH OIL TEMP

(4)
Put the other HYD PUMPS B ELEC switch to ON.

(a)
If the No. 1 GCU is tested, put the HYD PUMPS B ELEC 2 switch to ON.

(b)
If the No. 2 GCU is tested, put the HYD PUMPS B ELEC 1 switch to ON.

(5)
Make sure the LOW PRESSURE light remains ON.

(a)
If the No. 1 GCU is tested, the right LOW PRESSURE light remains ON.

(b)
If the No. 2 GCU is tested, the left LOW PRESSURE light remains ON.

(6)
Put the HYD PUMPS B ELEC switch for the GCU being tested OFF.

(a)
If the No. 1 GCU is tested, put the HYD PUMPS B ELEC 1 switch to OFF.

(b)
If the No. 2 GCU is tested, put the HYD PUMPS B ELEC 2 switch to OFF

(7)
Make sure the LOW PRESSURE light comes ON.

(a)
If the No. 1 GCU is tested, the left LOW PRESSURE light comes ON.

(b)
If the No. 2 GCU is tested, the right LOW PRESSURE light comes ON.

(8)
Make sure the other LOW PRESSURE light goes OFF.