Wanderlodge Owners Group

Wanderlodge Owners Group (https://www.wanderlodgeownersgroup.com/forums/index.php)
-   Electrical (https://www.wanderlodgeownersgroup.com/forums/forumdisplay.php?f=17)
-   -   Twin 20 amp to 30 amp or 50 amp Adapter (https://www.wanderlodgeownersgroup.com/forums/showthread.php?t=3178)

iamflagman 05-29-2009 10:13 AM

Twin 20 amp to 30 amp or 50 amp Adapter
 
I'll be the first to admit that electrical wiring is not my best department of knowledge, so I'll ask for ideas here.

I'm currently parked in the paddock (pits) here at Road Atlanta for this weekends SCCA race and I have access to two separate 20 amp outlets on separate circuit breakers, of which I am plugged into one of them and this limits me as to what I can use on the 'Bird. Being able to use two 20 amp circuits at the same time would give more amps to use, but still would require power management.

http://www.tweetys.com/images/produc...lay/552755.jpg

I came up with the idea of creating my own 2-30 amp into 1-50 amp outlet, similar to the one above but with longer cords. I have the two old 30 amp cords that came with my 'Bird which I no longer use and these could be used as part of the adapter and then use 20amp to 30 amp adapters like the one below, so that I can use similar 20 amp outlets in the future or the next time I come back here, where I am almost assured of being parked in the same spot next to the tech. inspection shed. The adapter of course could also be used for two 30 amp outlets. I will use a 50 amp female plug and housing that is available at Lowe's.

http://www.tweetys.com/ProductImages/55-9648.jpg

Shown below is the way I wired the adapter.

http://www.pbase.com/image/113615571.jpg

Any help, or ideas would be appreciated.

MRPutz 05-29-2009 10:52 AM

John, Not a bad way to be creative and get more power. The only thing I'd be concerned about is you are ASSUMING the park is wired correctly! :eek:

I'd create or purchase a tester to verify the two different outlets are indeed wired correctly before I tied them together! Could make for some interesting sparks! :D

My only other thought concerns load balancing. In a perfect world your power demands would be split evenly between both 30a sources. But that will not happen due to differences in resistance so I'd imagine there is still a possibility of tripping a 30a breaker as your power demands rise? I don't have any first hand experience with that so am talking mostly theory here. And I'd assume that would be a greater issue using a 20a & 30a together.

But I do like the concept and will be playing with that myself here soon. I'm thinking that the 30a/20a situation presents itself far more often than the two 30a sockets? But would be nice to have both. ;) I've never understood how we are expected to live on only 30a service? And it's funny how parks charge for the different outlets available. This device could get you the power needed from a 30a site vs a 50a site. Somehow I'd learn to live with myself by not paying the difference. hee hee hee

Maybe being from Arizona I have unique needs but running an airconditioner full time (sometimes two), a hot water heater, normal daily usage, an occasional microwave, hairdryer, curling Iron, batter charger, etc.. just doesn't happen on a single 30 amp source. :confused: I've seen too many burnt 30 plugs to comfortable settle for that so currently I always request 50a service. AND my '78FC35 doesn't have all the power hungry devices most people have.

Let me know how your project fairs.. I'll not be far behind.

bwinter1946 05-29-2009 11:47 AM

John,

I have one of those adapters as it came with the coach. I never have used it but recently I had the same issue as you. The camp site had two 30 amp hook ups and no 50 amp. So when I got back home I dug the adapter out and opened it up to check out the wiring etc. If memory serves it is wired the same as your plan. If you want: I will open it up again to be sure. I put it in my coach for the next time so it is still untested.

RGloverii 05-29-2009 12:05 PM

John,

I really don't think it's a good idea to do as you suggest. There is just too high of a potential for human error to creep into the equation.

As we all know, there are times when power poles are incorrectly wired (reverse polarity, no ground, etc). Your idea to tie two 20 amp 120v circuits together could potentially amplify the danger of an improperly wired power feed. In my opinion, not worth the risk.

I'll admit, very innovative thinking though. Theoretically you could make it work.

Ed Wimberley 05-29-2009 12:27 PM

20 Amp service
 
John
What you are thinking will work but as Michael stated purchase and USE prior to hook up a circuit poliarity tester, be certain that BOTH outlets have correct wiring before hooking up final connections.RETEST again at 50 Amp plug before powering the INN.
I already do this at some campsites,I have found out that most sites are wired even/odd on phase from site to site so that if you loose power your neighbor will not.

MRPutz 05-29-2009 12:50 PM

I've got to quit replying to these early in the AM.. hee hee hee

John's message stated he was tying a 30a circuit to each leg of the breaker box so the only balancing issues is not resistance but loads on each leg. Making sure both AC's and or hot water heaters are on separate legs.

My thoughts were to tie the two 30a (or 20a/30a) together to have them load share but that is when resistances come into play. If you load share you don't have to balance your loads in your breaker box so that is the advantage there.

Anyway, John's method is safe as long as you do test before plugging in. It's ok to be afraid of electricity, it's when you're not that you'll have issues. ;)

peteaeonix 05-29-2009 12:53 PM

John,

I have one of those dual 30 amp to 50 amp adaptors -- it works fine with two 30 amp outlets. Polarity is an important issue, the source outlets must have correct polarity. (You need to test it with one of those polarity testers from a home center -- use a 30 amp to 20 amp adaptor to use the typical tester on a 30 amp plug.)

Your wiring plan for the DIY adaptor seems correct -- but I leave that to the real electricians here.

If polarity on the source power is correct, the only potential snag is GFCI. Are the 20 amp plugs GFCI protected? If so, the normal imbalance between the 2 legs of your AC service in the coach will be assumed (by the GFCI) as a fault, and the GFCI breakers (on the power source) will trip.

I was never able to use my dual 30 to 50 amp adaptor successfully on any set up that included GFCI protection.

Living with 20 amps is pretty tough (especially in my all-electric coach) but it is enough to keep the battery charger going and a few lights. It's a little tough if you want AC, as a single AC draws about 15 amps all by itself. In a 'bird, it's hard to hold other AC draw to less than 5 amps -- and, when the compressor cycles on, if the source breakers are at all twitchy, they'll blow with the brief over-draw during compressor start up.

Note: I installed two "high efficiency" roof ACs on my coach -- these only draw 10 amps for the same cooling output as the standard 15 amp ACs. I have been able to operate one on a 20 amp circuit, taking care to not operate any other significant load at the same time.

Summary:
1. both source sockets must be wired with correct polarity. Test first.
2. GFCI source will trip the GFCI breaker. No work around (that I know of).
3. This all assumes no 220 vac appliances. There's a 50-50 chance that the sources will have the same phase, so 220 may not be available at all.
4. Even with dual 20 amp sources, it still requires careful power management and a knowledge of what's on which leg.
5. Dual 30 amp adaptors work best with dual 30 amp power sources as GFCI isn't normally an issue and the power management isn't as critical.

Best of luck.

iamflagman 05-29-2009 12:58 PM

Quote:

Originally Posted by Ed Wimberley (Post 20850)
John
What you are thinking will work but as Michael stated purchase and USE prior to hook up a circuit poliarity tester, be certain that BOTH outlets have correct wiring before hooking up final connections.RETEST again at 50 Amp plug before powering the INN.
I already do this at some campsites,I have found out that most sites are wired even/odd on phase from site to site so that if you loose power your neighbor will not.

I always checked any outlet that I will be using with a circuit tester for proper wiring and a voltage tester for correct voltage, plus I have a hard wired Progressive Industries Electric management system that will detect any of the problems that have Been suggested. http://www.tweetys.com/electrical-ma...rdwire-50.aspx

iamflagman 05-29-2009 01:04 PM

Quote:

Originally Posted by peteaeonix (Post 20852)
John,

I have one of those dual 30 amp to 50 amp adaptors -- it works fine with two 30 amp outlets. Polarity is an important issue, the source outlets must have correct polarity. (You need to test it with one of those polarity testers from a home center -- use a 30 amp to 20 amp adaptor to use the typical tester on a 30 amp plug.)

Your wiring plan for the DIY adaptor seems correct -- but I leave that to the real electricians here.

If polarity on the source power is correct, the only potential snag is GFCI. Are the 20 amp plugs GFCI protected? If so, the normal imbalance between the 2 legs of your AC service in the coach will be assumed (by the GFCI) as a fault, and the GFCI breakers (on the power source) will trip.

I was never able to use my dual 30 to 50 amp adaptor successfully on any set up that included GFCI protection.

Living with 20 amps is pretty tough (especially in my all-electric coach) but it is enough to keep the battery charger going and a few lights. It's a little tough if you want AC, as a single AC draws about 15 amps all by itself. In a 'bird, it's hard to hold other AC draw to less than 5 amps -- and, when the compressor cycles on, if the source breakers are at all twitchy, they'll blow with the brief over-draw during compressor start up.

Note: I installed two "high efficiency" roof ACs on my coach -- these only draw 10 amps for the same cooling output as the standard 15 amp ACs. I have been able to operate one on a 20 amp circuit, taking care to not operate any other significant load at the same time.

Summary:
1. both source sockets must be wired with correct polarity. Test first.
2. GFCI source will trip the GFCI breaker. No work around (that I know of).
3. This all assumes no 220 vac appliances. There's a 50-50 chance that the sources will have the same phase, so 220 may not be available at all.
4. Even with dual 20 amp sources, it still requires careful power management and a knowledge of what's on which leg.
5. Dual 30 amp adaptors work best with dual 30 amp power sources as GFCI isn't normally an issue and the power management isn't as critical.

Best of luck.


I automatically do not use any GFCI outlet and I'm currently running the center airconditioner and the battery charger on the one 20 amp circuit, the plug and outlet have not gotten hot at all, nor has the breaker tripped, I turn the roof air off at night and turn on the water heater. Most of my appliances run off of my inverter, supplied by the 8 Trojan T-105's.

yesmar 05-29-2009 02:55 PM

If you have separate battery chargers (such as the 94 bird), why not plug each battery charger into each 20 amp circuit and live off the inverter? I am assuming no AC's are running. My 94 inverter would run everything but hot water and AC's.


All times are GMT -4. The time now is 11:36 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.