Wiring a concession trailer...help (AC, water tank, vac, drain)

[Rutherfordton]

I am redoing an Airstream into an espresso shop and need to rewire it. I am not going to use the existing wiring but intend to wire up outlets and lights by running romex through conduits inside and under the trailer. I can pretty much accomplish that but am having trouble with the main and the power to it. I guess i should use a 100 amp main with a few 20 amp breakers, one for the lights and two maybe for the outlets. I will be running a freezer, a fridge, an espresso maker, and maybe a coffee maker constantly. Other appliances will be used less frequently, like a microwave, table top oven, etc. How should I expect to get the electricity to this trailer and in what form? Should I use a 30 amp cord to power the main? Will that provide enough electricity? Should I run a few 20 amp lines into the trailer? Help, I can't seem to get an electrician to look at this project and I can't seem to get started myself.
Thanks in advance.

[K'ledgeBldr]

Regardless of what appliances will be used more often than others- you'll need to figure the total amperage (peak amp) of all appliances. Then you'll know what your feed should be.
Run everything from a regular breaker type box. Feed the box from a female plug (rated for whatever your peak amp was) on the exterior. Your power cable (rated for your peak amp) will have a male on one end and a male on the other. But if you don't know what type of plug will be available to you- you may want to get several different plugs for changing out- or try and buildup some adapters.
You should never run romex through conduit because of heat build-up. Either use BX or buy multi strand in reels and pull it through conduit.
Put all the major appliances on separate GFCI breakers (probably 20amp) or GFCI receipticles (which ever is easier to access). Since this is a trailer, you are having to rely on the ground in the system- you won't have a ground rod. Any lights can go on a 15amp breaker. Try using either fluorescent or low voltage to keep your amperage down.

[BobKovacs]

Aside from the fact that it sounds like you're flirting with disaster here (as KB said above, romex in conduit is a no-no), what do you plan on plugging this trailer into once you get to your destination? Your total load sounds like more than a 30-amp circuit will handle, and it's not very common to get a 30-amp receptacle to plug into anyway.

[JBrown]

I also agree with above....sounds like trouble waiting to happen...I'm not surprised at all that your local electricians are runng away from that job.You're going to have a 100 Amp main feed with a 30 Amp cord ?? Am I reading that correctly ??


I'm curious as to what service you expect to find where ever your going to plug this into. Have you looked at what hardware is used when a boat is sitting in a slip and the owner connects up to "shore power" at the dock ? That is clearly a potentially electrical nightmare but the proper hardware exists to do it correctly.Often multipule cables are run (30 or 50 Amp) ,splitting the service load to the yacht. Hubble weather tight fittings etc aren't cheap but that's what I would be looking at.
Check out West Marine (for one example) for the kinda stuff I'm referencing. Hubbel.com makes excellent electrical hardware. Worth the money in hazardous environments.

[South Range Family]

I would say congratulations on becoming a carnie, but you are a concessionaire, not a carnie. A concessionaire is a small business owner that must also learn how to be an electrician, a plumber, maintenance man, security guard, cook, cashier, stockboy, contract negotiator, accountant, truck driver, and company CEO.

A carnie is an employee of the ride, and game companies. They are usually drifters, crackheads, and low lifes that will steal your power cord, and water hose in the middle of the night.

Let's start at the power supply and work towards your trailer. You will be expected to carry 100' of 4 conductor, stranded copper, 8 gage minimum (6 gage preferred) black rubber coated power cord. Some events will have a 4 prong dryer plug, most will hard wire you directly into a breaker box. Some will only allow their electrician to make the connection. Others will expect you to do it. Red and black are your hot legs of 120v each. White is neutral, and green must always be ground. You must train yourself to put one hand in your back pocket while working in a hot box. This prevents you from using both hands and crossing your heart with current. I carry a couple of different ends, plus spare Square D, and Cutler Hammer 240v 40 amp breakers.

You have a choice at the trailer end of your power cord. You can hard wire directly to a 100 amp breaker box, and carry your cord coiled on the tongue of your trailer. The second choice is a 50 amp twist lock connector with a recessed male plug mounted on the trailer. The female end is on your power cord. If it were to become unplugged, you don't want hot prongs exposed. This is a good way to keep the carnies from stealing your cord.

In the trailer you will have a 100 amp box. You have a choice of all GFCI breakers, or individual GFCI outlets. The most common setup is one circuit for fridge. Another for freezer. Then left counter, right counter, interior lights, and outside lights. If you use 20 amp breakers, you must use 12-2 romex. Don't waste your time with 15 amp and 14-2.
All wiring must be inside the trailer. The only thing allowed under the trailer is low voltage brake, and tail lights. You will also be required to have a copper ground rod connected to your trailer.

You will be inspected at every event. Some will be just the health department. Others will be health, fire, and electrical inspections. You must be prepared for all of them. You need a back flow preventer, and braided potable water grade hose. In most Eastern States 4 sinks are mandatory. Some require 5. You will also need a drain hose, and a blue waste water tank.

With an Airstream, I don't see how you will install a marquee. You will need to figure out how to light up the outside of the trailer. That's what draws the people in. Rope lights, and spots might be your only option.
If you have more questions, I have answers. They might not be the right answers, but I have answers.

[Bydand]

The working with one hand in your pocket is the oldest myth around when it comes to working with electricity and working in a live panel. Been doing it for 26 years and can assure you it makes NO difference.

Rest of it is very good. A while back someone posted that you should have a power cord with two male ends. BAD, BAD, BAD!! Common sense alone should tell you this is a very bad idea. if you plug it in first, then you have exposed live contacts. The argument that you plug it into the trailer first doesn't hold up, and the simple fact is that if you use the right material, there is zero need for it, other than being cheap. Cheap can injure or kill somebody in this case.

[South Range Family]

Many people have the tendency to grab the metal shaft of a screwdriver while twisting it with the other hand. It helps stabilize it while guiding it in. That's where it becomes dangerous. That's why I got into the practice of using one hand.

While attending aircraft maintenance school, all of my electrical instructors always told us to use one hand while working in hot boxes. If you managed to get hit, the current would most likely enter your right hand, and hopefully exit your right foot to ground. If you have both hands in the box, the currrent could enter your through your right hand, cross through your heart and exit through your left hand. We work with 28v DC, and 120v 400hz 3 phase. I am an all around aircraft mechanic. I work on everything from engines, structures, flight controls, avionics, and radar. I went to school over 20 years ago, and electricity is NOT my specialty. Maybe they were exaggerating back then, or just playing it safe. I couldn't say for sure.

[Bydand]

They were exaggerating. It is a good way to put a bit of good healthy respect in your mind to stay as well

I've been an Electrician for 26 years and have worked on every voltage you can think of up to and including 575 3 phase AC (10,000 if you count the output of small transformers, but I don't) and up to 400 Volts DC. Been blasted a few times, but 95% of the time it was my own stupid fault for being in a hurry, or complacent. Neither of which is a good thing to be working with electricity.

[Cosmic]

Originally Posted by South Range Family

Many people have the tendency to grab the metal shaft of a screwdriver while twisting it with the other hand. It helps stabilize it while guiding it in. That's where it becomes dangerous. That's why I got into the practice of using one hand.

While attending aircraft maintenance school, all of my electrical instructors always told us to use one hand while working in hot boxes. If you managed to get hit, the current would most likely enter your right hand, and hopefully exit your right foot to ground. If you have both hands in the box, the currrent could enter your through your right hand, cross through your heart and exit through your left hand. We work with 28v DC, and 120v 400hz 3 phase. I am an all around aircraft mechanic. I work on everything from engines, structures, flight controls, avionics, and radar. I went to school over 20 years ago, and electricity is NOT my specialty. Maybe they were exaggerating back then, or just playing it safe. I couldn't say for sure.

Defintely not some type of weekend myth. Your instructors were teaching it properly. Yes, put your left hand in your pocket. Touch as much as possible with only your right hand. You are attempting to influence the current pathway if you should get zapped. Nothing is for sure but it has been proven many times to been a factor in determining the pathway the current takes through the body.

Electrocution and death of a human is nomally caused by heart failure. If you can prevent current flow down the left side of the body, your chances are much better. In general the main factors involved in electrocution are current flow, pathway and duration. The general rule of thumb is 100 milliamps of current flow down the left side of the body is the threshold level to where death can be expected. It can be a complicated subject but a good electrical safety program attempts to have everyone well versed in exactly what is involved.

Here is a good article that starts to explain the basics.

Electric shock - Wikipedia, the free encyclopedia

Lots of things come into play. Even the type of shoes you are wearing. You can absorb a huge jolt of electricty as long as current does not flow in the left side of the body. Tissue / organ damage can occur but you may survive some huge current flows. Using only the right hand attempts to have the current pathway occur only in the right side of the body. It does not ensure that will happen, only makes it more likely in many circumstances.

In general we avoid putting the higher voltages in mobile applications for a number of reasons but in general you do tend to be more safe. The rubber tires acts to create a higher resistance path to ground through the human body. The same idea as having the rubber mats in front of major electrical and electronic equipment.

I think I would research exactly what is required in your local area and have it inspected. In particular things like cable sizes and where exactly is GFCI required.

Understanding exactly how electrocution occurs in a human body is useful for just everyday life. One thing our instructors used to say was attempt to visualize the potential current pathway you are setting up through your own body when creating some work situation. One joke was always work with the right foot in a bucket of salt water.

Firing up a trailer on a super juice load would be enough for me to rethink a bunch of potential safety issues. Would not view it as a process of just installing a higher voltage source but what potential safetly issues might I be creating.

In particular, the actual installation path for the wires and are you creating situations where wires can rub or chaff. The mobile application will see a lot more vibration than a normal house installation. What is required in terms of wiring runs to make them more resistant to damage.

And yep, I would still only plug and unplug things with my right hand. Old habits die hard. Not a sure fire warranty nothing will happen to you but it is a lot better than praying. Like all good projects, start with a view of safety and what is involved. The U.S. Navy has a lot of experience with death by electrocution. Most of them occur with 115 VAC. They have a safety movie called 115 VAC Your Deadly Shipmate. Understand how you die from electrocution and you then understand why certain safety practices are best followed. I sure would not be creating any type of jury rigged trailer.

Might take South Range Family advice to heart and also ask around at trailer parks and see what they advise in terms of practical installations even above what codes require based on experience. Might ask is fire alarms required. I know they are for campers.

[South Range Family]

I'm probably wasting my time. Because it looks like the original poster never bothers to check for replies.

Once you get into deep fryers you open up a whole new can of worms. That is when they start mandating exhaust hoods and automatic fire supression systems. My trailer is old enough that portable fire extinguishers are still allowed as the only fire fighting source. All mobile units are required to have at least one extinguisher with a yearly inspection tag. Mine are the smaller 5 pound units. Some Counties require the larger 20 pounders.

Coffee, and espresso go good with pastries. I'm assuming that's why you are planning on an oven. Eventually you will discover that those items don't really sell that well at some events. You will then start to sell nachos & cheese. Maybe get a popcorn machine, or shaved ice machine. I like soft serve ice cream too. Fountain drinks, and lemon shake ups are good money makers.

Once you have an operational trailer, you will find that your options are endless.
A 31' Airstream is a big trailer. Do you plan on building a partition, and installing a couple of bunks with a bathroom, or is it going to be all concession trailer?