S 864-006

 (2)  
Remove the DO-NOT-CLOSE tags and close these circuit breakers on the P11 panel:

 (a)  
11H17, FLT CONT SHUTOFF TAIL LEFT

 (b)  
11H18, FLT CONT SHUTOFF TAIL CENTER

 (c)  
11H28, FLT CONT SHUTOFF TAIL RIGHT

 S 864-009
 (3)  Remove the DO-NOT-CLOSE tag and close this circuit breaker on the P6 panel.
 (a)  6A1, BAT BUS DISTR
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 S 714-011
 (4)  AIRPLANES WITH FIELD OFF SWITCHES INSTALLED ON GENERATOR FIELD AND HYDRAULIC CONTROL PANEL; Test the generator field and hydraulic control panel installation as follows:
 (a)  
Make sure that the two GEN CONT switches on the P5 panel are off (out position).

 (b)  
Make sure that the APU GEN CONT switch on the P5 panel is off (out position).

 (c)  
Push the BAT switch on the pilots' overhead panel P5 to ON (latched-in position).

 (d)  
The white left and right FIELD OFF lights on the generator field and hydraulic control panel must come on.

 (e)  
The white APU FIELD OFF light on the generator field and hydraulic control panel must come on.

 (f)  
Push the BAT switch on P5 panel to off (out position).

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 FAULT SENSING - DESCRIPTION AND OPERATION
_________________________________________
 1.  General_______
 A.  The electrical power system is protected against source overloads and faults occuring during power distribution. Source power is continuously monitored and disconnected if its quality is unacceptable. System failure information is stored in the built-in-test equipment (BITE) of the control units. This can be accessed from the bus power control unit (BPCU).
 2.  Component Details (Fig. 1)_________________
 A.  Current Transformer Assemblies
 (1)  
Twelve current transformer assemblies are used to sense differential faults, and source overloads. The transformers are located in the main ac, ac tie, APU generator, and external power feeder and distribution system. Data monitored by the current transformers is sent to the generator control units (GCUs), or the bus power control unit.

 (2)  
The current transformers operate at frequencies between 340-440 Hz ac power. They are rated for continuous operation with primary currents up to 250 amps/phase.

 (3)  
The following table lists the names and locations of the current transformers in the system.

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MAINTENANCE MANUAL

Current Transformers Component Locations
Figure 1 (Sheet 1)

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T112 LEFT TIE BUS DPCT
T127 LEFT OVERLAP CURRENT TRANSFORMER
T105 LEFT GENERATOR DPCT NO. 1
FWD
LEFT GENERATOR POWER PANEL P31 B
T113
RIGHT TIE
BUS DPCT

T128
RIGHT OVERLAP
　
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