is this safe?

[Lunchbox7985]

for my little chuck wagon
http://www.tnttt.com/viewtopic.php?f=40&t=55888

let me run this by you. i found this online

http://www.myrv.us/electric/Pg/30amp_Service.htm

so according of it, 20 amps at 25 foot is good with 12 gauge. so i found this

http://www.menards.com/main/electrical/electrical-cords-outlet-adapters/extension-cords/12-3-25-lighted-yellow-outdoor-extension-cord/p-1908971-c-6410.htm

so im going to have a mini fridge, (1.3 amps) and a 700 watt microwave (about 6 amps). as well as a water pump (probably a little shurflo one), then an outlet on the back side to run to the tent which will have phone/ camera chargers, maybe a small lcd tv, and my redneck A/C (a fan on a cooler full of ice water, some copper tube, and a pond pump. figure some headroom for an ice maker and maybe a coffee pot and some other random stuff that hasnt popped into my head yet. i figure i may bust 15. and i dont want to have to worry about not using the microwave while the mini fridge compressor is running and stuff like that.

so on to my question, if i use that setup with a beefy 12 gauge cord, and an adapter to regularly plug into the 30 amp service line, do you think id be safe if i happen to make coffee and a breakfast burrito at the same time my fridge kicks on?

my main concern is using one of those 15 amp shore power inlets, obviously they call them 15 amp, but i wonder how much of that is referring to the style, and how much actually refers to their power handling. i figure if i use 12 gauge wire from my inlet to my fuse box (which will be at most like 3 feet of wire) i should be fine to handle a surge over 20 amps, and then maybe a continuous 17-18 or so for a couple minutes right?

an actual 30 amp cord (which is 10 gauge) is like twice the price, and i feel like its overkill for my chuck wagon.

[Dale M.]

A good quality 12 gauge cord should be fine.... I use a 12 gauge 25 foot cord in a 20 amp circuit with a MIG welder all the time and cord rarely even get s warm......

Thing to watch is if plug and receptacle on cord get hot... There may be slight temperature rise at plugs or cord as you near max current, but it should not be alarming hot...

You seem to have good understanding of the electrical loads and amp ratings of devices and breakers and yes if everything decides to kick in at once it will be pushing a 15 amp breaker to limit.... So you should not get into any trouble..... IF breaker were to pop on rare occasions I would not be too worried if everything turned on at once, if you are popping the breakers a lot, I would look for a problem...

A 30 amp (120 volt) adapter to a 15 (20) amp adapter for shore power pedestal or cord is valid also... IF shore power is rated at 30 amps or above I surely would want my own 15 (20) amp breaker between trailer electrical and shore power...

You should also test shore power for proper wiring and GFI circuit (if equipped) for operation before plugging in trailer cord...

Dale

[bdosborn]

Well, a #12 wire isn't rated for 30 amps, you should use a #10 with a 30 amp plug. Is there a reason you're using a 30 amp plug, why not go with the 15 amp plug? Those are found everywhere (including your garage I'm guessing) and you can run a 20 amp load through a 15 amp duplex receptacle (its a code thing). It doesn't seem like your loads justify the hassle of a 30A plug...

Bruce

[Dale M.]

Well, a #12 wire isn't rated for 30 amps, you should use a #10 with a 30 amp plug. Is there a reason you're using a 30 amp plug, why not go with the 15 amp plug? Those are found everywhere (including your garage I'm guessing) and you can run a 20 amp load through a 15 amp duplex receptacle (its a code thing). It doesn't seem like your loads justify the hassle of a 30A plug...

Bruce

Might want to consider what is on power pole at campsite before you get to restrictive on what is a absolute one should use....

The OP is asking about roughly a 15 amp load... And is asking how to do it safely.... Many solution and not all are correct, as not all are wrong.... IF it were not possible there would not be so many 30amp to 15amp adapters out there ...

Dale

[Lunchbox7985]

well i thought i posted a reply, but it dissapeared.

but ya, like dale said, im working with a potential 15 amp load. and in cars, pulling 13-14 amps through a 15 amp fuse can cause it to overheat and melt without poping. (car electronics is what i do for a living) so i dont want to plug into the 15 amp service, and pull 15 amps, as i see that as being dangerous, so really what i want to do is use a cord that can handle 20 amps, plug it into the 30 amp plug via an adapter, and have the standard 15 amp plug on my box like so



im going to have 2 15 amp breakers in my box (one for the microwave, one for the fridge) and split the other outlets between those circuits. then maybe a third breaker for a gfci outlet on the outside to run a cord into the tent.

i feel safer pulling 15 amps through a cord ratred for 20, then plugged into an outlet that can supply 30, and then just keep in mind that just because im using the 30 amp service doesnt mean i pull that much.

so i know im safe plugging into the 30, as i know you only draw as much current as you need, but my main concern was the "15 amp" plug i pictured above. do you think its going to be a weak link and overheat? i mean for a little more i can buy bulk 12 gauge wire and my own twist lock ends for it if you guys think that style outlet is really that much safer.

but keep in mind that the fridge probably only runs half the time, and im obvisously only going to use the microwave in increments of a couple minutes. so anything over 15 amps if going to be if im using the microwave, and the fridge kicks on, then it may spike over 15, then drop down to near 15. (i think i just convinced myself that im fine) but i still want your opinions on it.

microwave 6
fridge 1.3
hillbilliy AC maybe 2
phone and battery chargers insignificant
coffee maker 10ish (from a quick google search)

so i may be pushing 20 for however long it takes to brew coffee.

[bdosborn]

Well, a #12 wire isn't rated for 30 amps, you should use a #10 with a 30 amp plug. Is there a reason you're using a 30 amp plug, why not go with the 15 amp plug? Those are found everywhere (including your garage I'm guessing) and you can run a 20 amp load through a 15 amp duplex receptacle (its a code thing). It doesn't seem like your loads justify the hassle of a 30A plug...

Bruce

Might want to consider what is on power pole at campsite before you get to restrictive on what is a absolute one should use....

The OP is asking about roughly a 15 amp load... And is asking how to do it safely.... Many solution and not all are correct, as not all are wrong.... IF it were not possible there would not be so many 30amp to 15amp adapters out there ...

Dale

The original question was if it was safe to us #12 wire with a 30 amp receptacle and the answer is no. You're better off designing your system around a 20 amp receptacle if your going to use #12 awg wire, IMHO. That being said, I use #12 extension cord and a 30 to 15 amp adapter whenever I need to. The difference is that I have a 20 amp circuit breaker in my trailer so I know the trailer wiring is properly protected. Code requires that all commercial trailers be equipped with a circuit breaker as close as possible to the power inlet, which is what facilitates all RV adapters out there. As you said, there are different ways to skin this cat but #12 wire on a 30 amp circuit isn't the best way to do it. If a 15 amp continuous load is worrisome, bump the wire up to a #10 and all is good using a 30A plug. Or stick a 20 amp circuit breaker in your trailer if you want to use #12 wire.

Bruce

[bdosborn]

but ya, like dale said, im working with a potential 15 amp load. and in cars, pulling 13-14 amps through a 15 amp fuse can cause it to overheat and melt without poping.

<snip>

i feel safer pulling 15 amps through a cord ratred for 20, then plugged into an outlet that can supply 30, and then just keep in mind that just because im using the 30 amp service doesnt mean i pull that much.

Wiring devices are different from fuses, they're designed to carry the rated current continuously. A 15 or 20 amp device wont melt when it hits 15 or 20 amps.

Receptacle manufacturers, UL and the NEC are all on the same board together and know that 15 amp receptacles are being installed on 20 amp circuits. The 15 amp receptacles and 15 amp plugs are designed with the knowledge that they will often be supplied by 20 amp circuits. Internally, there isn't any difference between a 15 and a 20 amp receptacle. The pins are different though...

Bruce

[Lunchbox7985]

(forgive my scatter brained way of thinking things through)
what im really getting at, is i imagine i want to wire the trailer for 20. and i wanna know for sure that a 12 gauge wire, and an inlet like what i pictured is safe for 20.

second question, is if the campsite offers 15 and 30, can i fairly safely use an adapter to plug into the 30 in that instance since i may pull closer to 20

well they make adapters to plug your 15 amp plug into a 30 amp socket so i assume thats ok.

but i am right in staying that a standard household plug is seen in both 15 and 20 amp circuits right? and do i need a 20 amp main breaker if i do plug it into a 30 amp plug, i know 2 15s obviously equals 30, should i do a single 20, or do they make 10 amp breakers?

(sorry, this is what ive been trying to ask all along, ignore the other posts and just go by this one)

[pmowers]

(forgive my scatter brained way of thinking things through)
what im really getting at, is i imagine i want to wire the trailer for 20. and i wanna know for sure that a 12 gauge wire, and an inlet like what i pictured is safe for 20.

12 ga is fine for 15 amps for 20 feet, 30 amps for 15 feet. Keep in mind that these are continuous loads and you normally don't draw near that.

second question, is if the campsite offers 15 and 30, can i fairly safely use an adapter to plug into the 30 in that instance since i may pull closer to 20

well they make adapters to plug your 15 amp plug into a 30 amp socket so i assume thats ok.

You can attach a 20 A load to a 30 A source. Think about it, your standard household outlet is actually attached to the 100/200 A service to your house. When you look at your home breaker box, think about how many 15 A circuits you have compared to the rating of the main breaker.

but i am right in staying that a standard household plug is seen in both 15 and 20 amp circuits right? and do i need a 20 amp main breaker if i do plug it into a 30 amp plug, i know 2 15s obviously equals 30, should i do a single 20, or do they make 10 amp breakers?

If you look at some household outlets, you may notice that one of the slots is T-shaped. Those outlets are rated for 20 A, but handle standard 15 A plugs. Devices which require 20 A will have one blade perpendicular to the other, preventing them from being plugged into 15 A circuits, overloading them.

Yes, they make 10A breakers, they also make half-thickness breakers which allows you to install more breakers in the same space.
You should size your primary breaker to the size of the cord going from your trailer to the power pole. If you are going to use a 25 ft cord, then use a 12 Ga. cord and a 20 A breaker. Remember, the breaker only protects downstream. If you try to pull 30 amps, the breaker will trip. If it didn't, you could potentially overheat your extension cord or have too high a voltage drop which messes with motors and electronics.

In my distribution panel, I have a 20 A main breaker, and several 15 A breakers. If any one circuit pulls more than 15 A it will trip that breaker. If I draw more than the 20 through the main breaker, it will trip. I have a undercounter fridge, 45A 12 VDC converter, 1000 W microwave, 1500 W heater all in my CT as well as an external AC unit. I would never have everything going at the same time, but I have had the microwave, refrig and AC all running at the same time. Try and use as short of an extension cord as you can between the Marinco and the power pole.

(sorry, this is what ive been trying to ask all along, ignore the other posts and just go by this one)

Hope this answers some of your questions.

Pat

[Lunchbox7985]

Think about it, your standard household outlet is actually attached to the 100/200 A service to your house. When you look at your home breaker box, think about how many 15 A circuits you have compared to the rating of the main breaker.

that sentence just set my mind at ease, that makes so much sense. so im going to put a 20 amp as my main, then have 15s for each of the 3 circuits (fridge plus some outlets, microwave, and outside outlets)

If you look at some household outlets, you may notice that one of the slots is T-shaped. Those outlets are rated for 20 A, but handle standard 15 A plugs. Devices which require 20 A will have one blade perpendicular to the other, preventing them from being plugged into 15 A circuits, overloading them.

and i guess i never knew that, always wondered what those plugs were for. so basically if the campground has 20 amp service it will probably have an outlet like this



and i will be fine with my standard plug like this



but if it has the standard plug, i will probably want to use my 30 amp adapter, but i will be fine as long as i have a 20 amp main breaker right?

[bdosborn]

(forgive my scatter brained way of thinking things through)
what im really getting at, is i imagine i want to wire the trailer for 20. and i wanna know for sure that a 12 gauge wire, and an inlet like what i pictured is safe for 20.

A #12 wire is rated for 25 amps all though it's against NEC code to protect it with anything larger than a 20 amp circuit breaker. The inlet is also good for 20 amps.

second question, is if the campsite offers 15 and 30, can i fairly safely use an adapter to plug into the 30 in that instance since i may pull closer to 20

Just make sure you have land the #12 wire from the marinco inlet on a 20 amp main circuit breaker in you trailer. Then make sure you use at least #12 wire throughout in your trailer. You can split your circuits out how you like after that using whatever circuit breakers sizes and the correctly sized wire that works for you setup. BTW, it's an NEC code requirement that the pedestal at the campground contain a 20a GFCI receptacle. That's not to say you won't find 15 amp receptacles at older sites but FWIW...

Bruce

[Lunchbox7985]

you guys are awesome.

truth is, im probably never going to pull more than 10 amps at a time. but i remember my mother in law saying something in their camper once.

"well we have to make sure we turn the water heater off before we use the microwave, or it will pop the breaker"

i dont want to have to deal with that, or even think about it. i want to be able to use everything at the same time, even if i never do.

[Bogo]

BTW, it's an NEC code requirement that the pedestal at the campground contain a 20a GFCI receptacle. That's not to say you won't find 15 amp receptacles at older sites but FWIW...

Many sites won't have been rewired to the newer NEC specifications.

i dont want to have to deal with that, or even think about it. i want to be able to use everything at the same time, even if i never do.

Then wire it for 30 Amps in with a 30 Amp breaker... You've mentioned the redneck air conditioner so I'd expect a regular air conditioner in the future, and enough other stuff that it looks like you may end up loading down over 20Amps at once.

[bdosborn]

BTW, it's an NEC code requirement that the pedestal at the campground contain a 20a GFCI receptacle. That's not to say you won't find 15 amp receptacles at older sites but FWIW...

Many sites won't have been rewired to the newer NEC specifications.

Isn't that what I said?

Bruce