Luxury Coach Lifestyles - View Single Post - Battery Disconnects
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Old 04-04-2012, 01:45 PM   #9
77newell
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Join Date: May 2008
Location: Just North of Detroit, a surprizingly great city
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Quote:
Originally Posted by prairieschooner View Post
As a side note, I would question disconnecting the Negative (-) side. With the numerous systems supplying 12 Volts DC (Batteries, Chargers, and Conveters) I suggest that it would be better to disconnect the Positive (+) side or use a Double Pole Circuit Breaker or similar device to be sure that both sides (+ & -) are disconnected.
From the perspective of electrical current it doesn't matter what side the disconnect is on, unless the current can freely travel from one battery pole out into the coach systems and back again there will be no flow. However, picture the following. I'm safety wiring the nuts on the lid of a battery box in a confined space. The disconnect switch was on the positive side. The wire is a bit wrapped up in my hand when it happens to touch a bit of the positive side of the battery. OUCH - expletive deleted, followed by more of the same. If the ground side of the battery is disconnected no harm occurs when any positive side wiring or shorts to the chassis happens. If the positive side has the disconnect switch any contact to ground (chassis) between the battery and the switch will result in lots of expletives deleted. When the disconnect is on the ground side about the worst that happens if the contact is made to the chassis between the battery and the disconnect is that power to the coach is comes on. This difference matters in only a few cases, but my scars from the burns would say when it matters it really matters.

77 newell, 2007 civic toad, happy campers
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