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direction. A low resistance in both directions indicates a short. A high
resistance in both directions indicates an open rectifier.
Figure 19
Test Rotating Rectifier with Ohmmeter
Test Lamp:
Connect the leads of a test lamp, consisting of standard
flashlight batteries and a flashlight and built, as shown in Figure 20,
across the rectifier in one direction. Then reverse the leads. The lamp
should illuminate in one direction but not the other. If the lamp
illuminates in both directions, the rectifier is shorted. If the lamp does
not illuminate in either direction, the rectifier is open.
Figure 20 Test Lamp
Replace defective rectifiers with rectifiers of the same operating
characteristics as rectifiers installed in the generator at the factory.
Order rectifiers by part number, including the model and type of
exciter as well as the generator serial number.
Surge protectors may be included on the rotating rectifier assembly.
Disconnect one lead of the surge protector, and connect the leads of
an ohmmeter or makeshift test lamp, consisting of standard flashlight
batteries and a flashlight and built as shown in Figure 20, across
the surge protector in either direction. If the light comes on, the
surge protector is defective. Order surge protectors by part number,
including the model and type of exciter as well as the generator serial
number. Following replacement, make sure that the revolving field,
exciter armature, and rotating diode leads are properly secured.
Disassembly of Generator
The following disassembly procedures are meant to be a general guide.
Procedures for your generator may vary.
Remove the outlet box covers and disconnect the generator load leads.
Tag the leads and terminals to make certain the leads are correctly
connected when the unit is reassembled. Disconnect the other electrical
connections (current transformers, potential transformers, RTDs, AVR
and governor power supply inputs and outputs, and space heaters).
Shut down the oil supply system, and disconnect it from the generator
(if applicable).
CAUTION:
Do not pound on the
rectifier or armature windings.
WARNING:
Ensure the generator
has stopped and is de-energized before
disassembly. A rotating generator is
always producing some voltage and
contact with the leads or other devices
connected may result in serious injury or
death.
Cathode
Anode
Ohmmeter
Reverse
Diode
Standard
Diode
Содержание 4P10
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