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Unread 01-23-20, 01:29 AM
DrDave DrDave is offline
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Quote:
Originally Posted by cessnadriver View Post
Dr. Dave. Thanks for the reply. The newer C337s have a charging voltage of the mentioned 28.7. But mine C337 is a 1965 the maint. manual calls for 27.7 voltage. So when I contacted Zeftronics they said that was the ACU approved in their STC list? So I went with that one. DO I HAVE TO CHANGE TO THE HIGH VOLTAGE ACU? What about the STC approval?? I'll change the field wiring when I replace the switches. I do have another parts C337 that I could swap the circuit breaker panel, I didn't think of that! Although I did try to remove a couple of old C/Bs once and the screws attaching wires are REALLY tight and the screws are NOT very good quality. But you're right I should do the swap. QUESTION: The odd 8 AMP size in the panel are hard to find any chance I could replace them with the modern 7 1/2 AMP?? MANY THANKS. BILLS
BILLS:

A more complete answer would be that the battery installed in your plane in 1965 was a flooded lead-acid battery. In comparison to a Concorde sealed battery of today the charge voltage was about 0.6v lower than the specified charge voltages of the newer batteries. Running the older, lower voltage regulator will maintain the battery in an undercharged state. For best longevity the higher charge voltage of 28.5-29.0v is ideal in the 32-59 degree temperature range. Those numbers come from the Concorde manual. Since the manual is copyrighted I couldn't simply copy it.

Dave

Last edited by DrDave : 01-23-20 at 01:32 AM.
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