Trailer Power Cord?

[stkr]

What length power cord do you use for RV style hook ups?

I'm wiring for a 30amp inlet with power center, and I'm seeing cords of 12', 25', and 30', but not many 50' cords.

If I run the inlet receptacle to the rear of the trailer, then I guess 25' would be enough. Otherwise, I waste 14' of cord just running it outside the trailer.

Ideas/Suggestions?


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[dlockhart5x]

We carry two 50' s. It allows us to reach out for power when needed.

 

[franikk]

Always carry TWO! This hind-sight for me as I only had a 25 footer this past weekend and it was too short!

 

[mike_21]

I have a 30 footer attached to the RV and often have to pull the 25' extender out. I also carry a 100' ten gauge cable in the back and it too gets a lot of use.

 

[peter1968]

I agree carry more then one, I almost always have to use the 30' extention cord to be able to set up how I want.

 

[stkr]

Okay, I guess longer is better Now for the second part of the question...

What type of male plug is the most common at tracks? (see pictures below)

I guess for marine applications, the twist-lock 30 amp plug is the standard, but for RV type hookups, the TT-30 is the standard. My generator uses a twist-lock 20 amp, so I would still need an adapter for that, but since I'm probably going to have to make up my own cord with 10-3 wire, then I want to minimize the use of adapters if possible.

Oh yeah, who's got the best prices on 10-3 cable (service cord)? McMaster-Carr had it for $2/foot, and Lowes had it for $1.72/foot. Is there a cheaper source out there?

 

[Motofun352]

I bought a 100' 10 gauge for $130 from Tractor Supply about a year ago. Good for 20 amp service, it has standard 2 prong plus ground ends. Longer is NOT always better. You can easily overload a cord so make sure to buy a heavy enough gauge. Oh yeah, buy 2 of every adapter.

 

[peter1968]

I have multiple adapters, 30 amp to 15 amp, 30 amp to 50 amp. Most electrical hook ups for The RV are standard with the option to connect to 30 or 50 amps. I find a lot of the 30 amps see heavy use and are worn so I will use my 50 to 30 for a better connection.

As stated I would make sure you check the gauge of the wire for the length and amp draw. For a 100' you may want to use #8. Most electrical supply houses should be able to size that properly for you.

 

[JRA]

Shorter is always better, as in use the shortest cord that you can. As recommended above use 8 GA wire or bigger, and get multiple cords in differing lengths so that you always have one that is long enough without combining them whenever possible.

 

[stkr]

I fully understand the length vs wire gauge vs amps stuff.

One new question is...

The 50 amp RV hookups are normally a true 240V with two separate 120V phases. Do the 50A to 30A adapters just use a single phase and the other blade of the plug just isn't wired to anything?

The RV power center I'm going to use is a 45A single phase panel with a 30A main breaker. I'll be powering a few outlets/lights with the 120V section, an powering the original 12V wiring with the DC section.

http://www.progressivedyn.com/all_in_one_pd4000.html




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[beac83]

stkr;251890 wrote: I fully understand the length vs wire gauge vs amps stuff.

One new question is...

The 50 amp RV hookups are normally a true 240V with two separate 120V phases. Do the 50A to 30A adapters just use a single phase and the other blade of the plug just isn't wired to anything?

The RV power center I'm going to use is a 45A single phase panel with a 30A main breaker. I'll be powering a few outlets/lights with the 120V section, an powering the original 12V wiring with the DC section.

http://www.progressivedyn.com/all_in_one_pd4000.html




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Jim,
Yes, when you use a 50 to 30 adapter, only one side of the line is connected to the 30 amp outlet.

The 30 Amp connection is 120V. The 50 Amp connection is 120/240V, so they just use half of it.

Similarly, when you use a 30 A to 50 A adapter, both sides of the 50A line output are connected to the single ended 30A input. You don't get 240V service when using a 30 to 50 adapter.

Most common plug at the track for 30A is the RV type plug, as in your middle pic.

 

[Otto Man]

While the "most common" plug at the track might be the 30 amp, I would wire your trailer for 50 amp. Here's my recent trailer wiring drama:

Wired mine for 30 amp RV style plug. Worked great at VIR South, went to North to set up, they only had 50 amp receptacles. Great. I had no 50 to 30 amp adapter. I did have a 120v adapter to go into my 30 amp cord, but that still only gave me the max of 20 amps (The standard 120v outlet...all VIR 120v receptacles I saw are the heavy-duty 20amp instead of the usual house receptacle of 15amp)

Wiring my trailer for 50 amp would have allowed me to run the max amount of power, and had only a 30 amp RV outlet been available, with a 30 amp adapter, I would run zero chance of over loading any of my wiring, since it's been wired for 50amp already. Your breaker box was different, but I had picked up a 100amp breaker box from Lowe's. It had a dual pole 100amp main fuse. Since I wired it only for 30amp RV service, I had to use some left over 10 gauge wire and "jump" from one breaker to the other. (Note: This is frowned upon by some and deemed highly redneck, but it indeed works just fine, like it or not) Had I not done this, I could have only used 1 leg of breaker box power. Again, had I wired my breaker box with a 50 amp service, both would have worked, and here's why:

The 50 amp RV plug is indeed 240v. However, since my breaker box has two legs of power, I would have ran one black wire to each side of the breaker box - thus still giving me the full 50 amps of power, but since they aren't connected together, it's still only 120v.

I will be re-wiring my trailer to a 50 amp plug in the next week, and just have a 50 to 30 amp adapter. And yes, while JRA is completely correct on wanting the shortest length possible, if your trailer is wired for 50 amp, and you only have access to 30 amp...the extra cord length isn't going to matter all that much, since your extension cord will already be over kill for 30 amp service.

Oh...and one 25ft cord IS NOT enough!! I also learned this the hard way...

 

[JRA]

no need to jump one breaker to another. Just jump the two busbars together where you would normally connect the two sides of your line power. You can then feed the box through a 30 amp breaker which will act as the main breaker.

My trailer came wired for 30 amp. I built a set up to run it that is like a big extension cord with a small breaker box and receptacles attached to it. I bought a 60 amp breaker box and used a piece of 4 wire 8 ga service cord to feed the box through a 50 amp breaker. I then installed a 30 amp breaker that feeds a 30 amp RV plug on one side, and installed four receptacles on 20 amp breakers on the other side. So now any time I have access to a 50 amp RV hook-up I'll use this box to run everything. The trailer runs on one feed, and my tire warmers, coffee pot, fan, tools, and anything else I plug in to the receptacles runs on the other feed. It works great. Of course I could just convert my trailer to 50 amp which actually would have been easier and cheaper, but this way I have more receptacles on the outside that I can easily move around to where I need them.

 

[matt2212]

:notsure:I see X-rated has stayed out of this one

 

[stkr]

Thanks for all the replies and help. :cheers: I think I've finally decided on how I'm going to wire this. (see attached drawing)

Here's my goals for the end result:

1. Be able to utilize BOTH phases/poles coming from the piece of crap genrator.
--- Stupid L14-20 twist lock receptacle. Might rewire the generator to use a TT-30 receptacle.

2. Have 120 volt receptacles, and lights inside for any work I need to do. (easy part)

3. Have 12 volt trailer circuit "automatically" switch to the shore power converter. This is where the 12 volt relays come in.
--- The relay coils will be powered by the 12 volt converter, so whenever shore power, or the generator, is on, the relays will latch, and switch all of the 12 volt circuits from the truck's power, to shore power. The converter also has a built in battery charging circuit, so this will be used for the trailer brake back-up battery, and for charging the bike's battery when the bike is in the trailer.

--- I am also installing LED reverse lights on the trailer so I can see when parking the trailer at night. These backup lights, through the use of the relays, and a wall switch, will become area/task lighting for the pit area behind the trailer.

If I wire the system for a two phase/pole panel, then this lets me hook up to any RV receptacle available, or utilize the generator. Using a ON-OFF-ON switch on the Y-leg of the incoming two phse circuit, this allows me to feed both poles from a single phase 30 amp RV connection. Having the OFF position in the middle eleminates the possibility of having a phase-to-phase short (i.e. FIREBALL). If using the generator, or pluging in to a 50 amp service, then the switch goes back to normal.

Now, I'm probably just going to use a 30 amp main breaker instead of a 50 amp, because I honestly do not need a 50 amp service, and will never use that much power. By using a 30 amp breaker, this also allows my to use an 8-AWG, or a 10-AWG, power cord without the concern for overheating the cord. There is a huge price jump when you start looking at power cords with a 6/3 with 8/1 configuration. (Think $400 for a 50 foot cord )

I know I'm thinking way too much on this, but it has now become a quest.

 

[Otto Man]

I can definitely understand the concern of cost of extension cords from the 50 amp to 30 amp...the price jump is crazy!

 

[stkr]

Otto Man;252062 wrote: I can definitely understand the concern of cost of extension cords from the 50 amp to 30 amp...the price jump is crazy!

Yep, and to think I "used to" work in a place where spools of that stuff were just laying around.


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