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The Home Smithy
The Home Smithy, Home Builder
Category: Home Improvement
Satisfied Customers: 9619
Experience:  #1 Home Improvement Expert 30+ years experience
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I have a concession trailer. I need electrical power,

Customer Question

I have a concession trailer. I need electrical power, lots. Equipment list includes: Commercial microwave (2), Freezer (3), fridge (1), 4' flourescent lights (3), outside spot lights (3), Gas Ovens w/electrical fans (2), commercial Coffee Maker (1), outside lighting rope lighting 200', outside recepticals (3), Electric countertop steam table (1), Cash Register(1). plus misc. receptacles (4). Currently I have a GE 70 amp box, two 30 amp and two 20 amp breakers feeding all. power source is a single 25 amp cord from fairgrounds. I use two of them, one for an outside freezer only. I'm not new to wireing, I need to know what modifications / changes to make to have comfortable power input. most event locations will hook me up to more if I'm properly wired. Most cable runs to their power source are under 200'. I can read most schematics, I understand electrical terminology somewhat...I have built 4 houses to NEC code so I'm not a beginner...drawing supplied if requested. TY, Rob
Submitted: 9 years ago.
Category: Home Improvement
Expert:  Rich replied 9 years ago.

Hi ..

Are you having power problems .. ??

is this a new trailer to you ??

are you wanting to add devices ??

Thanks .. Rich


Expert:  The Home Smithy replied 9 years ago.


Being a former ride jock I am familliar with what you are trying to do. I have worked on more than one floss wagon during my time doing spots for ole Dangerous (Davis) Enterprises.

If you could provide a drawing of your present set up I can provide the needed modifications to get you running smoothly.

You can e-mail the drawings to [email protected]

Just let them know that it is for The Home Smithy and they will see to it that I get them.

Best regards; The Home Smithy

Customer: replied 9 years ago.

Hi Smithy!

Schematic and diagram (equipment placement) en route. Here is what I have:

Power cord IN is 110v (2 wire+grnd) All power out is 12/2 w/grnd NF where needed under trailer thru plastic pipe.

1/2 of box is utilized. (2 wire, not three in)

I can re-wire the whole thing if I have good schematics and know what to get for parts if I have to.

I'll need a power supply cord of 200' length for most supply applications. What Size?

Breaker Box can go on outside, not a problem...I'll buy weatherproof.

recessed female or male on outside to hook up to supply?

Dogbone type? (to connect if their connection is different)...

my phone number: (NNN) NNN-NNNN Albany New York, USA area

my regular Email: rewymanvt @

Expert:  Joseph replied 9 years ago.
First what you need to do is change the wiring coming into your trailer. It needs to be a 4 conductor wire, not a 3. The reason for this is that you are risking a shock hazard by not having your trailer properly grounded. You accomplish this by running a cable with 2 hots, neutral and a ground. Your new panel needs to have both a neutral bar and ground bar separated so they are not electrically connected. Next you will need to run a #6 wire from your grounding bar in the panel to the chasis frame of the trailer.

Now as for the size of the service, you will need a 50amp 220v 4 wire cable to service this trailer. Most all units such as yours run off of of this type of service. Now if you were able to provide me with the amperages of all the units running inside your trailer, I can be much more specific.

As for the panel, I would recommend putting Cam Lok panel mounts. All fairs, convention halls etc will use cams as a standard of making the electrical connnections. See pic:

What you would need is Red - Black - White - Green cams. These would surface mount on your Nema 3R electrical panel. Like I said in most cases, they will run feeders to your trailer and with cams already attached, all they do is tie them into your panel and your off and running. If them running cable to your trailer with cams already attached is out of the question, you will need a 4-4 SO cable. This will allow you up to 75amps and if you only needed 50, then that would make up for the voltage drop in the system. Additionally, I would still hook up the panel mount cams and then put cams on your cable for easy install and tear down. See pic:
Now your cable wont exactly look like this, but these are the cams for your cable and it will be one cable not separate feeds.

Now I know this is allot to take in, but if you have any questions or need clarification on anything I stated, please dont hesitate to ask. Have a great night.

Customer: replied 9 years ago.
Reply to The Home Smithy's Post:

Sorry Smithy, tried to follow their "Paste Here" directions for my diagrams...didn't work out...Oh well...on to another day...


Expert:  The Home Smithy replied 9 years ago.

Ok lets try this then. Are the drawings in .jpg format? If not what format are they in. I can help you to upload them to other free servers if needed

Rob you can use to upload the files to. Just click on browse and locate the file on your computer. Click on upoload and then copy the link the site gives you and paste it here. Let me know if you have any problems.

Customer: replied 9 years ago.
Expert:  The Home Smithy replied 9 years ago.

Ok Rob I have the picture just need a little translation of part of it. The words pointed to by the arrow if you please. Once I know what it says I can proceed to edit the drawings for you. I should have these done by tomorrow afternoon.

never mind it is "extention cord".

Expert:  The Home Smithy replied 9 years ago.

Small problem Rob.

I had about 1/2 of the drawings done and accidentily hit the reset button of my computer. 2 hours worth of drawings...poof!!

Well back to the drawing board.

I will have these for you by the morning.

Customer: replied 9 years ago.

A HA! I am not alone in the wonderful world of "Senior Moments"!

Why is it that the "Delete Button" / " Reset Button" are not three feet away for computer guru's like us???? :o)


Expert:  The Home Smithy replied 9 years ago.

ROTFLMAO!! you too huh.

I actually remove the escape key from my keyboard. That and that damn caps lock are the first thing to go bye bye. Unfortunatly the power switch in the back of my computer has to stay there. that is what I actually hit by accident yesterday. The fan in my power supply was getting old and would raise one loud screeck on occassion. A good whack stops it. I missed! Yell Replaced fan immediatly after posting my last message to you.

Anyways here is what I have for you. Have a look and we can edit as needed. All wiring is just like house wiring, unless indicated otherwise.

I forgot to add a plug for the exterior light string and freezer. A good twist lock should work fine for the string, and a standard recepticle for the freezer.

As for the main feed wires. You can probably get these cheaper if you go to a welding supply store and tell them what you need to do. You will need a mimimum of #6 stranded cable (3/8" welding lead) These can be layed out flat as opposed to having a large wire that someone might trip on. Just watch that the carneys don't swipe them on slough night. Rather than use a connector at the trailer I would go ahead and hard wire it to the panel. Add a couple pieces of #5 rebar to hang them on and your set

Another thing you may wish to consider is a mains breaker at the trailer before the breaker panel. Some spots I did required this, but most did not. They considered the switch at the feed source as the mains.

The Home Smithy, Home Builder
Category: Home Improvement
Satisfied Customers: 9619
Experience: #1 Home Improvement Expert 30+ years experience
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Expert:  The Home Smithy replied 9 years ago.


Joseph caught a big mistake in my drawing. The breaker sizes are wrong. They should be 15 and 20 amp breakers not 20 and 30.

Sorry about that. I guess I need to do these things earlier evening instead of early morning.


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