Usage:
All SR 4 Generators With Outboard Exciters
- SUPPLEMENT: 04/24/89
SERVICE MAGAZINE; MARCH 27, 1989; PAGE 13; "Exciter Rotor Retaining Bolt Torque Specification" for all SR 4 Generators with outboard exciters. In the third line of the right hand column, put a mark through the word "plated." Replace the word "plated" with the words "exciter rotor."
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Reference: Service Magazine; October 3, 1988; Page 9; "Main Rotor Shaft Changed To Eliminate Loose Connecting Bolts" on SR 4 Generators with 580 and 680 Series Frame Numbers.
The exciter rotor is held on the main rotor by four bolts. These four bolts pass through the exciter rotor laminations, to the main rotor shaft. It is important that these four bolts are correctly tightened to prevent them from working loose. Put 9S3263 on the bolt threads before they are installed. If the exciter rotor is fastened to the shaft with four 5/16" bolts, they should be tightened to a torque of 35.4 N·m (26 lb ft). If the plated is fastened to the shaft with four 3/8" bolts, they should be tightened to a torque of 55.8 N·m (41 lb ft). After all four bolts have been tightened, check the torque on each bolt again to ensure correct bolt stretch, even if the exciter rotor lamination relax slightly.