15 AMP TO 30 AMP QUESTION

[Karalyn]

I was out to camping world again (thought I was done there this year ha-ha)
I was looking for a small type plug in to go from my 30 amp cord to the 15 amp receptical without pulling the 30 amp cord out of the plug in (they had nothing that turned to work!).
I inquired about plugging my orange power cord, the regular 15 amp one into the trailer electrical system. The guy said that would work fine, and I could then use the 50 or 100 ft cord with no problem as I was hooked up to regular household current (like in my house or garage) . He says if using all 30 amp wiring, cut back to 50' or less but if using the regular household outside orange power cord pluged into my Casita 30 amp cord, I could go to a longer cord.
OPINION PLEASE?
Thanks!

[Joe MacDonald]

sounds like you're looking for a converter plug, but I'm not quite sure.
AFAIK, you have said the Trailer has a 30 amp end on it's cord, and you want to plug it into a 15amp receptacle.
Is this right?

there is an adapter made, it looks like this.
Club Price $2.49
Reg $2.77
Catalog Item # 24493 ( camping world)

[Darwin Maring]

The addapter is also sold at WalMart.

[Suz]

He says if using all 30 amp wiring, cut back to 50' or less but if using the regular household [b]outside orange power cord pluged into my Casita 30 amp cord, I could go to a longer cord.
OPINION PLEASE?
Thanks!

I advise caution on this. Not all orange cords are created equally. Don't let the words "15 amp" or "heavy duty" fool you. Check the wire guage that's imprinted on the cord. Do not use 14/3; 12/3 is okay but borderline. I personally use a 50 foot 10/3 (10 guage/3wire). Yes, it's heavier than the others, but I feel it's safer for both you and your trailer.

NOTE: I only charge my battery, run my small (5K BTU) A/C, or lights with this set up. I don't run (or have) a fridge with 110.

[Al V]

your cant run everything off a 15 amp breaker . like a/c and microwave. or heater and microwave. or heater and a/c lol that is hot water heater in electric mode. that's the one that got me once .

[Karalyn]

Thanks, I have that adapter shown in the picture. I just wanted a longer cord. I am headed on Sunday to a campsite (at my brothers place on the lake) that I need a 100 ft cord for. Was hoping I could get by with it for the air conditioner.

[Curtis F.]

Most reasonably priced 100' extension cords will have significant voltage drop when trying to pull 15 amps thru them. That voltage drop will be the early death of your Air Conditioner. I don't know the electrical math, but I would guess you would need 8 gage or less wires. That much copper wire gets expensive and heavy. You might be able to do it with 100' of the regular 30 amp RV cord, if you have 30 amps available to plug into. A 15 amp circuit simply will not deliver enough juice.

Curt

[Thane]

I the following info on this related link. It is repeated here for convinience. http://www.fiberglassrv.com/board/index.ph...topic=20327&hl=

I'm not an electrical engineer, but I play one at work and I think the following is accurate.

For a 15 amp current, the extension cord voltage drop per linear foot and the total drop across a 50 and 100 foot extension cord is as follows:

10 Gauge 0.01550 Volts/ft 0.775 Volts for 50 ft 1.55 Volts for 100 ft
12 Gauge 0.02468 Volts/ft 1.234 Volts for 50 ft 2.468 Volts for 100 ft

For a 30 amp current, the same data is as follows:

10 Gauge 0.03100 Volts/ft 1.55 Volts for 50 ft 3.10 Volts for 100 ft
12 Gauge 0.04936 Volts/ft 2.468 Volts for 50 ft 4.936 Volts for 100 ft

So if you use a 12 gauge, 100 foot long extension cord connencted to a typical home 15 amp line, the voltage drop is approximately 2.5 volts between the wall and the trailer.

If we assume that the trailer has a built in 25 foot 10 gauge line, an additonal voltage drop of 0.3875 volts will occur. This is a total voltage drop of almost 3 volts or approximately 2.7 percent of the nominal 110 volts available. Additional voltage drops due to internal trailer wiring and bad luck will drop the voltage by 3% or more. Plus we should assume there is a measurable voltage drop between the power pole outside the house and the electric plug on the side of the house.

What all this means is beyond me. If your device stives to maintain a constant power output then the current will increase by 3% to compensate for the 3% voltage drop. This adds to the current draw which results in a higher voltage drop and the cycle continues until a thermal or current limit or a stability point is reached. In other words, the lower voltage means your pumps and fans work harder which will force them to work even harder to maintain the necessary power level.

This voltage drop and current increase is part of the reason extension cords shouldn't be hooked together. This is also why my extension cords get so darn hot at Christmas.

[Curtis F.]

Found this info on another site Extension Cord ratings.

His numbers show more voltage loss than those above. What ever the real numbers are, people have had problems with long extension cords.

Curt

[Patrick M.]

I looked up the Coleman Mini-Mach A/C supplied by Scamp and it draws 8.2 amps (without heater), or 1,000 to 1,280 watts depending on conditions. I would think a 15 amp cord should work just fine. No?

Coleman recommends 12AWG supply wires.

[Dan Meyer]

I've run 50 to 100 foot 14 AWG extension cords and run my A/C many times since I purchased my Scamp in August 2000. I do understand that this is not the ideal situation, but I've done it, and had no problems so far.

-- Dan Meyer

[Darwin Maring]

Dan, You are more than likely putting to much of a strain on the AC compressor with the 14G wire. I use a 12G and it tends to start the compressor quicker.

Next time you use it, get the AC running then go and feel the 14G extension cord and it should be warm. One important note: Make absolutely sure you do not have a knot in the cord as this is the poingt where it will get to hot and melt the insulation.

DR

[Dan Meyer]

If 14 AWG isn't good enough to carry 15 amps, why is my house wired with 14 AWG cable on the 15 amp circuits?

-- Dan Meyer

[Darwin Maring]

Dan, The answer is because the builder saved money by going with the less expensive 14G wire. That seams to be the way everything here in the US has gone, cheapest by the lowest bidder, just to get by.

My house is wired with 12G except for the extremely high load areas that have 10 and 8 and I still use a 15Amp breaker on the 12G wire. The long 14G cord draws amps and takes away from what your load on the end may need.

Your house also does not have 100 feet of 14G with an extremely heavy load at the end. Houses normally have shorter runs and branch circuits so the power does not have to travel such a long distance.

Run your egg with the Air C on and other ac devices then go and feel the extension cord to see if it is warm.

If I try to run my air compressor on a 14G extension cord, it will draw to may amps, the compressor labors and the breaker pops however if I use a 12G extension cord, it powers right up, no laboring on the motor part, no problem.

[Darwin Maring]

Dan,

Our Scamp is not a 15 Amp connection, it is a 30 amp connection and it breaks out to 15 amp branch circuits at the breaker pannel.

Here is a test you can try: Run the air conditioner with other stuff turned on such as tv and the other normal things then turn off the air conditioner, wait 5 seconds and turn it back on. Will it start up or just hummmmm and will it pop a 15 amp breaker that your extension cord is pluged into.

[Patrick M.]

Turning on an air conditioner again without letting it sit for 2 minutes is a good way to break it. Not a good idea. The $20 thermostat I used in my A/C Thermostat project actually has such a timer built into it.

I think the heating up of the extension cord is a good test, although all of the info I've seen would indicate that a 14 gauge, 50' cord should work just fine for our 8 amp A/Cs.

[Dan Meyer]

The real problem here is the possibility of too low of a voltage at your camper to start your air conditioner compressor.

If you are running your A/C while at home, the voltage at the outlet the camper is plugged into is probably pretty good - at least 115 volts, possibly a bit higher. The voltage drop across a 100 foot 14 AWG extension cord carrying 8 amps is about 4 volts. At home this is no big deal, as you still have about 110 volts at the camper.

If you try to run your A/C in a campground where you start with the voltage at the outlet is around 110 volts (or maybe even less...), you end up with 106 volts running your air conditioner - not a very good situation.

This is one reason why it is important to monitor the voltage being supplied to your camper.

If an 8 amp load causes your extension cord to become warm, throw it away. It is probably a 16 or 18 AWG extension cord, which most certainly is not adequate for the job.

And finally, don't do as someone suggested above and turn on your A/C within a minute or two of shutting it off. The pressures in the compressor will be much too high to allow it to start, no matter what size or length extension cord you are using. What happens when this is tried is you trip the overheat protection in the compressor motor, resulting in no cooling until the compressor cools off. This usually takes longer than it takes for pressures to equalize, and when the compressor cools it resumes normal operation.

-- Dan Meyer

[steveh]

Somewhat along the same lines - I recently purchased a 1972 Amerigo and here's the wiring situation. Incoming 30 Amp to circuit breaker box containing two 20 Amp breakers. One breaker is connected to the converter and one is wired throughout the camper for normal 120V use. I smoke-tested the converter last weeked (literally) - so it's no good.

What I'd like to do is keep the 12V/120V sides apart and use a 120V/1.5A battery tender on the battery and keep the 12V side alive. I don't see any big deal with this, but please advise!

Here's the problem on the 120V side:
Dometic frig = 2A
Microwave = 9A
A/C = 8A
Battery Tender = 1.5A

So you see I'm already over 20A... I haven't gone and physically looked at the wiring yet, but some info I found in the camper's paperwork indicating it's 12/3.

My proposed mod is to disconnect/switch off the 20A breaker supplying the converter and leaver the converter switched to the battery (everything works fine right now) and replace the other 20A breaker with a 30A breaker to power up the appliances. Any problems you see?

Thanks in advance for any help - just found/joined this site a week or so ago and have learned quite a bit! Also, I'll try and get some pics up soon.
Steve

[Brian B-P]

...My proposed mod is to disconnect/switch off the 20A breaker supplying the converter and leaver the converter switched to the battery (everything works fine right now) and replace the other 20A breaker with a 30A breaker to power up the appliances. Any problems you see?

Since I understand 12-gauge wiring to be inadequate for 30A service, I would not use a 30A breaker on any circuit in this trailer (or mine, which is generally similar).

If the 20A breaker which currently feeds the converter is not to be used for that anymore, why not use it to supply a separate circuit for the air conditioner? The original 20A breaker would then be left to supply the other AC appliances for which it was intended. This would require running a cable from the breaker panel to the air conditioner outlet.

[steveh]

Brian,
Thanks much for the reply - and a damn good idea! That's what I'll do; there's already a piece of triplex running to the trunk for the A/C and battery tender so I'll just move that to the other breaker and leave the converter alone.
Have a good 4th,
Steve