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Craig · 09-29-2002, 11:45 AM

I'm replacing my water heater with a LP/electric combo unit. I'm trying to figure out how I'm going to handle the wiring. There is currently no access to the water heater from inside the TT (I had to remove rivets and a panel in the bathroom). This means that there is no access to the electric on/off switch on the rear of the WH, unless I create an access panel.

So here's my question. Rather than hard wiring the water heater, can I attach a cord and plug to the water heater? This would allow me to leave the electric switch in the on position, and I could simply plug and unplug when I want to use electric. It would also save me from having to splice into the electrical system. If it is possible, could I simply wire a heavy duty extension cord?

Thanks in advance!

thenewkid64 · 09-29-2002, 12:13 PM

You need to be careful modifying the electrical hookup. depending on the amperage that is required by the heater you could have a major fire hazard if you use undersize wiring. Also plugging in to an existing outlet could overload the circuit you attach it to.

My electric hookup is run from the heater to my main electric panel and has a single breaker installed that I use as an on/off switch. It may be more difficult to install but will be easy to use and be safe. What is the amperage draw that the heater is rated for? Does the installation manual state what size wire is required? Do you have any unused slots in the breaker panel?

niftypkg · 09-29-2002, 12:31 PM

Wiring to the CB panel sounds like your best bet and safest. The 6g hot rod draws 4.5 amps, The 10, 7amps. The built ins maybe more. My CB seems to have a 20 amp spare breaker which would work fine. Tom

Craig · 09-29-2002, 12:38 PM

This is what made me aske the question - in the installation instructions there is a section that reads:
"When a cord and plug connection tot he power supply are used on water heater, power cord must be UL listed as suitable for damp conditions, hard or extra hard usage. It must be a flexible cord such as type S, SO, ST, STO, SJ, SJT, SJTO, HS or HSO cord as described in National Electric Code, ANSI/NFPA 70. The length of external cord to water heater, measured to face of attachment plug, shall be no less than 2 feet nor more than 6 feet. Supply cord must be a minimum of 14 AWG and attachment plug must be rated at 15 amps."

thenewkid64 · 09-29-2002, 01:57 PM

Here is the rub "measured to face of attachment plug, shall be no less than 2 feet nor more than 6 feet."

Do you have an outlet within 6 feet? Even if you do then there is the issue of the fact most circuits that are built into the trailer are 15 amp cicruits, plugging in the WH would put you at the max load for the circuit. Then there is the safety issue, if the unit draws 15 amps I would not want to be standing there when that load gets plugged in(sparks).

Is your excella a rear bath or side bath?

Rear bath would be easy to hook into the panel, side bath would be a bit more work.

Craig · 09-29-2002, 04:14 PM

Brett,

OK - I guess it's not a good idea. It's a center bath... I haven't measured, but I do have 2 outlets that are pretty close to the water heater.

Maybe the electrical wiring I'll leave to a professional. Just hate to do that since I've done everything myself (so far).

Craig

john hd · 09-29-2002, 05:51 PM

your maximum distance is determined by wire size, if you use larger wire you can go farther, and you should go directly to your breaker panel. you do not want heavy loads on outlets(because they wear out like everything and can over heat)

i'll see if i can find a "minimum wire size calculator" and post it here for you.

john

john hd · 09-29-2002, 06:08 PM

here it is
http://www.pljohnson.com/electrical/...voltdrop.shtml

john

Craig · 09-30-2002, 07:35 PM

Since I don't know much about electric, wiring to the CB may be out of the question for me. So I'm considering returning the LP/electric combo and just going with LP. I wish I started this thread before I had the new heater delivered!

But let me ask another question. Based on what I'm reading this probably isn't a good idea either, but can I wire the water heater by splicing into the 120 v line before an outlet?

Thanks,

Craig

john hd · 09-30-2002, 09:15 PM

probally not, however you could wire the heater into one of the outlets you mentioned and blank the face plate off.

you could use type "so" cord from the junction box on the heater to the wall box just eliminating the outlet. if you could live without it. assuming the existing wire to the outlet is the right size.

type "so" cord is just heavy duty extention cord with rubber coating. not unlike the cord that powers your trailer. very flexible with a black coating and multiple stranded copper conductors.

in the long run it would be better to wire it direct to your breaker panel.

john

davidz71 · 10-01-2002, 07:06 PM

The forum knows that I am not an electrical whiz after the 110 v. in the campground fiasco but it seems to me that if you think you think you have the ability to wire into the 110 v. before an outlet then you probably have the ability to run the correct size Romex wire from the breaker box to the water heater area and run the wire into a junction box. Wires from the WH would be connected to the romex inside this junction box. You can buy some of the junction boxes which are waterproof. One of the threads posted earlier showed what happens when water drips onto a junction box so you would have to be careful where you installed it. After tracing the powercord from my electrical reel on the roadside to a junction box where they were connected to Romex which then ran past the WH and to the rear compartment, it seems that would be the safest way. The question is, would you be able to run that type of heavy wire to your breaker box by yourself? I'll leave the connections inside the box to the experts on the forum.

thenewkid64 · 10-01-2002, 08:21 PM

David71 AKA craig,

You learned a lot from your experience and now have a good basic undertanding of how things are connected in your excella. I personally think that is a good thing. Electricity is all fun and games until some one gets hurt.

Craig,

I will attempt to give you some direction here, but remember free advice is worth less than you paid for it.

There are only a few rules to abide by when working with AC power.

1. Make sure the trailer is unplugged BEFORE pulling breaker panel covers or messing around in oultet boxes.

2. The black wire is the dangerous one!, this one carries the 120 volt + side. Green is good, it is ground. White is safe it is neutral and acts as the - side for the voltage.

3. Do as others have done. When you pull the cover off the breaker panel you will find all the grounds are combined, all the neutrals go to the common buss and the hot or black wires attach to the breaker. Take a close look at a breaker, you will need one of the same type/brand that is rated for the water heater. This assumes that there is an empty slot in the breaker panel.

4. Using romex that is rated for the load, run it from the breaker panel into the cabinet where the water heater is installed. If your trailer is a rear twin you should be able to run it under the bed and across the rear to the breaker box. This may reqire dilling holes in interior walls. I would reccomend getting some type of cable hangers while you are at the hardware store. Use these to secure the wire after you have run it so it does not get pulled/caught by stuff under the bed or in a compartment. You will also need a romex strain relief on the breaker panel. It will be just like the ones that are there from the factory.

5. Hook it all up, black, white and green on both sides. Put the covers/panels back in place and plug the rig in with the new breaker off.

6. Make sure the heater is full of water and flip the breaker! You should have hot water in 20 minuites or so.

7. If you are not comfortable with any of the above instructions/suggestions do not hook up the AC portion of the heater. Fear of AC is a good thing, safety should come before saving a few $$$.

8. Ignore 1-7 and befriend a neighbor that understands AC and is willing to help for the cost of a couple of cold ones. These should be enjoyed AFTER, not during.

Sorry for the long winded post, I just want to help everyone fix everthing.