RV Electrical Safety - Page 6

Tango · 09-07-2015, 08:07 PM

Very...good...thinking. On stuff like electrical, if you are not an expert...HIRE ONE!

Samweld · 01-14-2021, 03:02 PM

Im an electrician in IA, I have a journeyman class A license currently and will soon be testing for my masters license, i was a mechanic before i was an electrician and have experience with DC and AC wiring. Im sure I wont have answers for everything but i will do my best to point you in the right / safe direction. Im new to this forum but happy to help.

musigenesis · 01-14-2021, 08:46 PM

I have one of the chinese diesel air heaters sitting in a box but before I can install it I need to set up a DC power source for it. I have a 15 amp inlet in the bus for shore power, and I need a transformer of some sort and some people here have suggested I should also have a car battery or something in the circuit to smooth out surges.

What sort of gear would you recommend for this, including any additional gadgets I might need and what sort of wire I should use? My bus is going to be mostly AC but I have this heater and also a few other gadgets that will need to run on 12V DC, like a stove vent fan, an on-demand propane water heater, a roof vent fan and a DIY toilet fan (and maybe a couple of other things) down the road.

Thanks for any suggestions! I really need to get off the schnide and order all the gear I need for the heater since it's getting colder, but so far my little electric space heater has been doing the trick.

Phatman · 01-14-2021, 09:57 PM

Hey Musigenesis. When you say you have a 15 amp inlet on shore power, are you saying you are plugged into a15 amp circuit at your house?

musigenesis · 01-14-2021, 10:02 PM

Quote:

Originally Posted by Phatman

Hey Musigenesis. When you say you have a 15 amp inlet on shore power, are you saying you are plugged into a15 amp circuit at your house?

I have this thing installed in my bus: https://www.amazon.com/gp/product/B08CV1SM7H/ which they call a "15A 125V" inlet. It's actually plugged into a 20 amp circuit at my house.

Phatman · 01-14-2021, 11:35 PM

Quote:

Originally Posted by musigenesis

I have this thing installed in my bus: https://www.amazon.com/gp/product/B08CV1SM7H/ which they call a "15A 125V" inlet. It's actually plugged into a 20 amp circuit at my house.

I am assuming that the 20 amp circuit is not a dedicated circuit. If it is, then why replace your cord with a #12 SJO cord? I am assuming that Amazon cord is just temporary? What is the wattage of the diesel heater? An AC to DC converter is only good for 2.5 to 3 amps. Radio Shack used to sell them. Don’t think they are in business anymore. Numark also makes one.

Samweld · 01-15-2021, 07:12 AM

somewhere on the heater there should be a place where it says how many amps of 12v dc or watts (which can be divided by 12 to get amps) that the heater needs for a fan (I'm assuming since its a diesel heater that the heat source would be the diesel).
once you know how many amps its asking for you can find the correct ac to dc converter/ power source.
as far as using a battery in line, you can hook up the heater to a battery but you would then need a charger for the battery, but that would allow you to use it without being hooked up to shore power.
does the heater come with a way to control it?
a thermostat?
depending on the size of the bus you probably won't need to run it constantly and you may want to be able to control it if that's even possible.
easiest way to get the specs should be a nameplate on the unit itself somewhere. if it's all in Chinese than it can usually still be deciphered because they all usually contain similar info.

Samweld · 01-15-2021, 07:29 AM

as far as wire:
wire size is determined by amperage
wire insulation is determined by voltage and what it needs to be resistant against (sun, abrasion, chemicals etc.)

I would recommend stranded wire over solid (so not romex)
and for most of what you mentioned you could probably get away with 12awg
stranded for the AC loads.

for circuit protection you can use residential circuit breakers.

I could really go down a rabbit hole on wiring your bus so I will stop for now but any other specific questions I can answer.

rossvtaylor · 01-15-2021, 08:55 AM

Quote:

Originally Posted by Samweld

I would recommend stranded wire over solid (so not romex)

I'm old enough to be old school. I learned to use only stranded wire in vehicles and have also done some work on aircraft (under the supervision of avionics techs), where only specific stranded cabling is permitted. So, while I'm with you on the preference for stranded wire the RVIA "code" now "allows" the use of Romex-type solid wiring. I'm not saying that makes it the best, but I do admit that I need to keep learning things and maybe solid wire's not as likely to fracture from vibration as I always thought.

Regardless of the wire type, I'd never use a twist-on wire connector in a vibrating vehicle...so no wire nuts for me, which are permitted under the RVIA guidelines. I much prefer Wago connectors or crimp connectors. We want our buses to be better than RVs, right?!

Samweld · 01-15-2021, 09:29 AM

So I just found out about the RVIA code in the last few days while reading some other electrical posts here, I plan on purchasing a copy of both the nfpa 1192 and the ansi/rvia Low volt standard. My preference for stranded wiring stems from similar experiences, I worked in racing for awhile and everything was stranded wire (with high heat resistance) and crimped fittings (soldering by itself was considered too brittle for the level of vibration). I would never put a wire nut in a moving vehicle unless it was my last last resort. I certainly won't argue that it is acceptable to use solid wire I have seen it done in lots of build videos. My experience with standards is that they tend to be the minimum expectation and in many instances its worth going above and beyond the code.
I personally won't be using any solid wire (not counting the data cabling which is solid but also 24awg)and I won't recommend it, but I also won't tell anybody they are "wrong" to use it.

lornaschinske · 02-18-2022, 08:27 PM

After much hoop jumping in order to post links (which I cannot do in a private message), I managed to locate my very old username and got a new password just to update my original post's links. Apparently my RVLife password wouldn't let me post anything in the forums. So here are the updated links in my original post....

For the RV Electrical Safety information, I suggest you buy Mike's book from Amazon amazon.com/No-Shock-Zone-Electrical-Safety-Michael-Sokol-ebook/dp/B00L2DWBD8/
The noshockzone.org is gone. You can find some of the articles here https://rvelectricity.com

DIY testers and how to use them https://www.myrv.us/electric/index.htm
30 amp DIY tester https://www.myrv.us/electric/Pg/tester_30amp.htm
50 amp DIY tester https://www.myrv.us/electric/Pg/tester_50amp.htm

Phred's Poop Sheets are here http://www.manmrk.net/tutorials/RV/phred/phredex.html

Good luck.

turf · 02-19-2022, 12:16 AM

Hey Lorna!!!

long time no see!
nice to see you back.

somewhereinusa · 02-19-2022, 05:48 AM

Hey Lorna.

cadillackid · 02-19-2022, 07:55 AM

Quote:

Originally Posted by rossvtaylor

I'm old enough to be old school. I learned to use only stranded wire in vehicles and have also done some work on aircraft (under the supervision of avionics techs), where only specific stranded cabling is permitted. So, while I'm with you on the preference for stranded wire the RVIA "code" now "allows" the use of Romex-type solid wiring. I'm not saying that makes it the best, but I do admit that I need to keep learning things and maybe solid wire's not as likely to fracture from vibration as I always thought.

Regardless of the wire type, I'd never use a twist-on wire connector in a vibrating vehicle...so no wire nuts for me, which are permitted under the RVIA guidelines. I much prefer Wago connectors or crimp connectors. We want our buses to be better than RVs, right?!

in the data cabling world.. there are certain Loops that are necessary in buildings at "flex points".. when cabling risers for high rise structures (yep your high rise office buildings flex.. a LOT!").. typical data wire is solid conductors.. Loops and slack points are p[laced to minimize tension and over-flex of wire at points diesginated as Bendy-joints by the building engineers..

seems the same would be true in a bus.. ie wire that goes from a solid wall around a corner or from wall to roof you would want to leave a "service loop" to allow for the bus to flex.. and any wire in a wall would not be pulled banjo-string tight..

my own personal preference though in walls would be BX just to give that extra layer of protection against rub through .. but im sure there's something in the code for protecting against rub through..

DeMac · 02-19-2022, 08:28 AM

While there are no expansion gaps on a bus, I also install burn loops, at devices and make wide turns around 90°s or when turning through stud holes. I'm into it. Mostly, there ought to be zero "flex" or movement to 95% of our raceways. There are few exceptions.
The NEC Chapter 3, “Wiring Methods and Materials,” helps us to understand why its safer than vibrating, bouncing, & rubbing. Anti-shorts, bushings, gromets, nipples & plumbers puddy all help with the friction.

Matencio · 03-26-2022, 08:16 PM

None of these are available...

Matencio · 03-26-2022, 08:29 PM

Let's see if you can help me. I have a 5500-watt generator from Westinghouse that I want to use. It has a 30 Amp receptacle. Do I use a two-headed cord for 30amp to run from the generator to the service into my breaker panel? I'm thinking I put a 30amp receptacle on the outside of the bus and then hardwire that directly to the main lugs in the breaker panel. From the panel, I run my home runs out running on 120 only unless this is capable of 240. It's a bus and I'm running six to eight circuits so I won't overload any circuits inside. The kitchen will have three circuits because there's a water heater- (one circuit) refrigerator and stove are propane. The microwave will have its own circuit and counter appliances will have their own circuit. The bedroom has its own circuit for lights and TV, office/living room has two circuits for two PC's/ monitors etc. TV and lights and bathroom has a circuit for lights and exhaust fan. Should I use a 200 amp breaker box or 100 amp.

TheHubbardBus · 03-27-2022, 09:55 AM

Quote:

Originally Posted by Matencio

Let's see if you can help me. I have a 5500-watt generator from Westinghouse that I want to use. It has a 30 Amp receptacle. Do I use a two-headed cord for 30amp to run from the generator to the service into my breaker panel? I'm thinking I put a 30amp receptacle on the outside of the bus and then hardwire that directly to the main lugs in the breaker panel. From the panel, I run my home runs out running on 120 only unless this is capable of 240. It's a bus and I'm running six to eight circuits so I won't overload any circuits inside. The kitchen will have three circuits because there's a water heater- (one circuit) refrigerator and stove are propane. The microwave will have its own circuit and counter appliances will have their own circuit. The bedroom has its own circuit for lights and TV, office/living room has two circuits for two PC's/ monitors etc. TV and lights and bathroom has a circuit for lights and exhaust fan. Should I use a 200 amp breaker box or 100 amp.

Please don't take this the wrong way, but many of the questions you ask indicate that you don't have the fundamental understanding (at this time) necessary to safely design and install your electric system. One of us could answer every one of your questions directly, and it would end up being the questions you never even knew to ask that would be your undoing. There's no reason you can't learn what you need to, and none of us 'know it all', but you do need to have a certain level of knowledge and experience under your belt before having specific questions answered is actually a help. I personally feel it would be irresponsible to answer your questions - knowing that you might very well go out & try to implement them - because it's clear you're just not 'there' yet. Again, the questions you don't know to ask are what are likely to cause an electrocution / fire hazard to yourself and your family.

If I were you, I'd seek out the counsel of a local electrician, to if nothing else guide you in your efforts & inspect your work, if not do it for you. Or perhaps you can find someone on the forum nearby to give you a helping hand (I'd offer, but you might as well be on another planet considering the distance between us). Or, if you have the time and are ambitious to learn, you can certainly expand your knowledge. I see in another thread you're a teacher so self-directed learning shouldn't be any issue for you. Here are a few links you may find useful.

Navy NEETS Intro to Electricity & Electronics

NFPA 1192: Standard for Recreational Vehicles

National Electric Code

Matencio · 03-27-2022, 10:17 AM

Thanks for the input. I was a journeyman and helper way back in the early 80's. I teach middle school now. I have some skills and many that will come back as I start working on electrical again. I've probably forgotten much because it was a long time ago. Right now I'm trying to get knowledge before I buy and build the bus out.

FYI, I will have an electrician do some of the work like tying into the panel and I'll pull my home runs, connect switches, receptacles, and the laborious parts of the build to save money. I need to have it certified for RV parks and a licensed electrician is needed for that.

That's why I'm asking the questions. I wired my entire house five years ago (thieves broke in and stole all of the wiring just before we moved into the house) so I have the experience to do basic electrical. I had it inspected afterward and the electricians passed everything on the first visit. Never had a problem. This schoolie is a little different and that's why I'm reaching out for advice. Power from the generator to the breaker box is where my weakness is. Your concern is appreciated and I'm not going to build a fire trap. However, I don't need to spend more either. $150 an hour adds up fast. Knowledge fixes that. If you can help me figure out what I asked, that would be great. Again, thanks for replying.
Mike

TheHubbardBus · 03-27-2022, 11:40 AM

"Do I use a double-headed cord?". Sounds like you're suggesting the use of a suicide cable, which you absolutely should not. "Unless this is capable of 240". How many hot legs is 30A service comprised of? "Hardwire directly to the main lugs of the panel"... will you be bonding neutral/ground at the panel? You should know not to and why. You should also understand the neutral/bond grounding requirements of your source (gennie/shore). "Should I use a 100 amp or 200 amp breaker box?" Is there a reason you'd want a 200A panel with a 30A input?

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