Bob;

 

My assumption is that the circuits coming off the bus are all protected near the bus; so putting protection on the feed wire near the bus doesn’t protect anything.  But I guess the discussion doesn’t mean much without a larger context.

 

Al G

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of bobperk90658@bellsouth.net
Sent: Thursday, December 06, 2007 10:41 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: circuit breakers

 

 

Sorry that I didn’t make my thoughts clear.  My thinking is that the cable is just an extension of the positive terminal of the battery.

If there is no possibility of the wiring shorting out to ground, (This could be what if’this to death) you can protect for the maximum amount of current your cable can conduct.    If there is any possibility that the cable could be shorted to ground then, yes protect at the source.  I would think that a plastic plane with the positive cable in an isolated raceway would present itself as a good candidate for the first scenario.  A switched disconnect could be inserted at the battery and remotely and manually opened for a fill good safety feature .   In any instillation you have a certain amount of unprotected wiring between the battery and the buss, this only extends that length.

In my mind the cable is just an extension of the positive battery terminal, especially if the cable is sized large enough to carry the entire load plus 100%.  This may go contrary to national wiring code but if you want control of the operation from the pilot seat then this is what is needed.

 

Bob Perkinson

 

Bob Perkinson

 

-------------- Original message from "Al Gietzen" <ALVentures@cox.net>: --------------

If you want to protect the wiring from the battery to the buss place a fuse or CB close to the buss. 

 

Bob Perkinson

 

Bob;

Not sure I understand that.  The protection of the wire should be near the source, not at the far end.

 

Al