Power Light while on DC power

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   There is logic behind the rules in the NEC. Lots of smart people from many professions have collaborated to develop it over many many years, and it has avoided countless fires and saved countless lives. You can do whatever you want of course but just know that in doing so you are assuming you know better than all those experts. 
In this case the logic is that by placing all disconnects, switches, fuses, and circuit breakers in the ungrounded (positive) conductor you can count on the circuits being dead when those devices are open. If you put some disconnects one line and some in the other it is very easy to inadvertently get current flow when you don't expect it.

There is nothing "iffy" about the applicability of the NEC to RV's because of jurisdictional differences. The Code gets updated every 3 years and then has to be adopted by each authority having jurisdiction. So you can find one AHJ on one cycle and another on a newer one. 

But, keeping the neutral connected and grounded and switching the hot conductor has been in the Code from before anyone on this forum was born, it is fundamental to electrical safety strategy in North America. The only exceptions are some industrial applications where the equipment won't work properly unless its on a floating circuit, and then there has to be special ground fault detection equipment in place. So, no matter what jurisdiction you are in and what code cycle you are on, you are non compliant if you are switching the grounded (negative) conductor. 

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offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Topic: Power Light while on DC power Posted: 01 Nov 2020 at 11:19am
	There is logic behind the rules in the NEC. Lots of smart people from many professions have collaborated to develop it over many many years, and it has avoided countless fires and saved countless lives. You can do whatever you want of course but just know that in doing so you are assuming you know better than all those experts. In this case the logic is that by placing all disconnects, switches, fuses, and circuit breakers in the ungrounded (positive) conductor you can count on the circuits being dead when those devices are open. If you put some disconnects one line and some in the other it is very easy to inadvertently get current flow when you don't expect it. There is nothing "iffy" about the applicability of the NEC to RV's because of jurisdictional differences. The Code gets updated every 3 years and then has to be adopted by each authority having jurisdiction. So you can find one AHJ on one cycle and another on a newer one. But, keeping the neutral connected and grounded and switching the hot conductor has been in the Code from before anyone on this forum was born, it is fundamental to electrical safety strategy in North America. The only exceptions are some industrial applications where the equipment won't work properly unless its on a floating circuit, and then there has to be special ground fault detection equipment in place. So, no matter what jurisdiction you are in and what code cycle you are on, you are non compliant if you are switching the grounded (negative) conductor.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

mcarter Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 07 Apr 2016 Location: Greenbrier, TN Online Status: Offline Posts: 3419	Posted: 01 Nov 2020 at 10:18am
	Thanks OG, I'm happy the way I do things. The NEC is a fine "code", very iffy on RVs and jurisdiction is the responsibility of local authority, who can change or delete NEC guidelines. Basically I put the disconnect where it is most convenient and I don't have a preference.
	Mike Carter 2015 178 " I had the right to remain silent, I just didn't have the ability."

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 01 Nov 2020 at 9:20am
	No, disconnects, fuses, and circuit breakers should always go on the ungrounded conductors of any electrical system, never on the neutral (grounded) conductors. For 12Vdc systems that means the positive conductor get the fuses and disconnects. That is an National Electric Code requirement, which does apply to RVs. The reason is that if you disconnect the negative at the battery the whole negative side of the 12v circuit can be hot afterwards. Basically, you should wire up 12Vac systems just as you would a 120Vac system. I think the confusion comes from the recommendation to disconnect the negative first when replacing or otherwise maintaining a battery. That is not inconsistent, once you lift the battery negative conductor you should also remove the positive.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

BMJ Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 May 2020 Location: Virginia Online Status: Offline Posts: 24	Posted: 01 Nov 2020 at 8:12am
	Thanks!

mcarter Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 07 Apr 2016 Location: Greenbrier, TN Online Status: Offline Posts: 3419	Posted: 01 Nov 2020 at 7:37am
	On RVs I use the negative. On motorized vehicles I will use either, the Old NHRA rules said it had to be on positive side. Half a dozen of one and 6 of the other.
	Mike Carter 2015 178 " I had the right to remain silent, I just didn't have the ability."

JR Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 31 Aug 2018 Location: Manistee, MI Online Status: Offline Posts: 376	Posted: 01 Nov 2020 at 7:17am
	I would put it on the positive side of the battery and remember to get a switch large enough to handle the amperage you are using (minimum would be 30 amps).
	Jay 179/2019

BMJ Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 May 2020 Location: Virginia Online Status: Offline Posts: 24	Posted: 31 Oct 2020 at 11:20am
	Thanks.. put a disconnect switch on the negative battery terminal. Didn’t even think of the other transient pulls mentioned...thanks!

JR Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 31 Aug 2018 Location: Manistee, MI Online Status: Offline Posts: 376	Posted: 31 Oct 2020 at 10:55am
	There are many things that have a parasitic draw like: the CO2 alarm, the antenna booster (if not turned off), the tank level indicators, the radio, and tv. Also the brake break away switch if it tripped will drain the battery quickly. Your newly installed main battery cut off will shut all these down if you installed it up front by the battery (ies). Hope this helps.
	Jay 179/2019

BMJ Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 May 2020 Location: Virginia Online Status: Offline Posts: 24	Posted: 31 Oct 2020 at 10:18am
	Not sure why I have a battery drain with everything off...I just put main battery cut off... any other insights most appreciated

Buffalohunter Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 12 Oct 2019 Location: Bellingham, Wa Online Status: Offline Posts: 57	Posted: 12 Aug 2020 at 7:16pm
	So it’s a winegard 7542...somewhere around $30...still searching for a cheaper price, but is it really worth it in the long run? This is a 2020 and they couldn’t even put in a switch that works...at least for 2 years? Should have bought the extended warranty? Sold used...only 2 weeks off the lot then returned for a larger unit. Oh well the pod still serves its purpose and is fun. For now the light is out.
	R-pod-2020 189 2013 Toyota Tacoma