Post by charliemyers on Jun 7, 2018 6:32:23 GMT -8
vikx please feel free to delete this if it's wrong...that's what the rules for this 110 Electrical say. I won't feel insulted or take it personally.
This may be a slightly advanced 110 electrical topic, but it's a rather simple concept and is easy to deal with so I just want to toss this out there because I don't recall having come across a thread on VTT yet that deals with it (there probably are several posts, but I don't recall having seen one yet). Does anyone use a line breaker in their box as a "main" breaker? These subpanels that we use in campers usually lack a space for a main breaker, so I intend to feed the shore power into a line breaker in order to provide over current protection for the remainder of the circuits.
When I install a new 120V distribution panel in my '61 Compact that I'm currently rebuilding, I'm planning for a 30 amp service. Say for example I go to a camp ground that happens to only have 50 amp service available (chances are slim, yes, but with the trend in today's megagigornomous RV's I can see where it can happen) and I use an adapter to connect my 30 amp inlet to the camp ground's 50 amp service...in the event of some sort of catastrophic electrical failure if I'm not protected by a 30 amp breaker in my box, then my next layer of protection is the 50amp breaker owned by the campground. Now some of you might think that I'm sounding like the sort that's planning for a zombie apocalypse, but short circuits and other phenomenon do happen with electricity. Not a lot thank goodness, but it happens. And when that happens, I don't want my camper to burn down and ruin my weekend.
So how would I deal with it? Connect the incoming shore hot wire to a 30 amp line breaker. Connect the incoming shore neutral and ground wires to their respective buss bars. Use a 10 AWG (or larger) wire to jumper the two lugs in the breaker box as normal. Add any other "under 30 amp" breakers that I need for the circuits that I need. The total of your other breakers can add up to more than "main" breaker (completely acceptable by the code), but if your total draw exceeds the main breaker then that "main" breaker is going to trip which prevents your precious camper from becoming an instant heat source.
Is there anything completely wrong with this approach? If so please set me straight. I'm about 90% certain that I saw a post on Repairing Yesterday's Trailers with a box wired this way (doesn't mean that it's right), there's at least one post on the "airforums" (Airstreams & kin...again, doesn't mean that it's right), and I've talked to a number of electricians (much closer to being right) that have told me that it's not only a good idea, but apparently thousands upon thousands of the more recent RV's & campers came from the factory wired like this.
I'm not saying that this is a requirement or even a recommendation from the NEC (National Electric Code), but I do know that the NEC is all about making electrical "idiot proof" so that it's difficult for even advanced idiots to start a fire with your wiring. To me this is big step toward that goal. There might only be a .01% chance of a catastrophic event happening, but for an extra $10 for a "main" breaker with very little change in the way it's all connected...why not?
If anyone would like pictures, I can find some from other sources to point you toward. Or maybe over the weekend I can mock up the new breaker box that I have to help explain it if this post is still up in a few days. Sorry this is so long! I don't often have too much to say, but I guess on this topic, I did.
This may be a slightly advanced 110 electrical topic, but it's a rather simple concept and is easy to deal with so I just want to toss this out there because I don't recall having come across a thread on VTT yet that deals with it (there probably are several posts, but I don't recall having seen one yet). Does anyone use a line breaker in their box as a "main" breaker? These subpanels that we use in campers usually lack a space for a main breaker, so I intend to feed the shore power into a line breaker in order to provide over current protection for the remainder of the circuits.
When I install a new 120V distribution panel in my '61 Compact that I'm currently rebuilding, I'm planning for a 30 amp service. Say for example I go to a camp ground that happens to only have 50 amp service available (chances are slim, yes, but with the trend in today's megagigornomous RV's I can see where it can happen) and I use an adapter to connect my 30 amp inlet to the camp ground's 50 amp service...in the event of some sort of catastrophic electrical failure if I'm not protected by a 30 amp breaker in my box, then my next layer of protection is the 50amp breaker owned by the campground. Now some of you might think that I'm sounding like the sort that's planning for a zombie apocalypse, but short circuits and other phenomenon do happen with electricity. Not a lot thank goodness, but it happens. And when that happens, I don't want my camper to burn down and ruin my weekend.
So how would I deal with it? Connect the incoming shore hot wire to a 30 amp line breaker. Connect the incoming shore neutral and ground wires to their respective buss bars. Use a 10 AWG (or larger) wire to jumper the two lugs in the breaker box as normal. Add any other "under 30 amp" breakers that I need for the circuits that I need. The total of your other breakers can add up to more than "main" breaker (completely acceptable by the code), but if your total draw exceeds the main breaker then that "main" breaker is going to trip which prevents your precious camper from becoming an instant heat source.
Is there anything completely wrong with this approach? If so please set me straight. I'm about 90% certain that I saw a post on Repairing Yesterday's Trailers with a box wired this way (doesn't mean that it's right), there's at least one post on the "airforums" (Airstreams & kin...again, doesn't mean that it's right), and I've talked to a number of electricians (much closer to being right) that have told me that it's not only a good idea, but apparently thousands upon thousands of the more recent RV's & campers came from the factory wired like this.
I'm not saying that this is a requirement or even a recommendation from the NEC (National Electric Code), but I do know that the NEC is all about making electrical "idiot proof" so that it's difficult for even advanced idiots to start a fire with your wiring. To me this is big step toward that goal. There might only be a .01% chance of a catastrophic event happening, but for an extra $10 for a "main" breaker with very little change in the way it's all connected...why not?
If anyone would like pictures, I can find some from other sources to point you toward. Or maybe over the weekend I can mock up the new breaker box that I have to help explain it if this post is still up in a few days. Sorry this is so long! I don't often have too much to say, but I guess on this topic, I did.
