Unregulated

When the aircraft is equipped with VR-1010-24-1A regulators allowed by Service Instruction 0766-354, Rev II, the overvoltage testing procedure is not achievable. The solid-state voltage regulators are not adjustable to a range (over 31.5v) that will adequately test the overvoltage relays. During a ground run and adjustment of the new voltage regulators, one failed and caused an overvoltage condition. It is this technicians opinion that the test procedure for the overvoltage relay should be changed to include removing and bench testing the overvoltage relays.

Editorial Staff

Sunday, September 30, 2018 at 12:00 AM ET

Verified

Key Takeaways:

Beechcraft Model 35-C33A Debonair
Shorted Voltage Regulator

Overvoltage warning light illuminated during operation. Installed new voltage regulator (p/n R1530B), started engine, switched on electrical system and the warning light came on. After troubleshooting with manufacturer’s service department, unit shorted internally, which the manufacturer would not warranty because they said the alternator was at fault. Replaced faulty new regulator with part number listed in parts manual—system works fine. This unit will not work with this system no matter what the manufacturer says.