firedoc
Sacramento, Ca
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I have purchased an adapter as per the title. We are volunteering at a NF&W hatchery and are the only volunteers. They have two pads, both wired for 30A. We have a 50 A coach. We expect to hit some really high temperatures here this summer and would like to utilize both air conditioners without the hastle of trying to do it on one 30A service. Today I set up the adapter. I tested the adapter (commercial product) and it appears to be wired correctly. I plugged one 30 A leg of the adapter into our stand and the other leg of the adapter into the other pads stand and then plugged the 50 A end into the PI EMS. When I turned on the breakers the EMS gave an error of E3 which means high voltage on leg 1. And of course the EMS shut down and would not pass any current. It said leg 1 was like 220 volts! I disconnected it and used a DVM to test each standard. They appeared to be wired correctly. (I had previously attached the EMS to each stand independantly and it had said everything was fine).
This set up should work. Any ideas.?
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Old-Biscuit
Across the USA
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A 30A adapter takes one 110V AC leg and jumpers it to feed Both legs on the 50A side.
You have a 50A adapter with two 30A plugs on the other end (a 'Y' adapter)?
One 30A male plug end plugged into a 30A receptacle and the other 30A male plug end plugged into a 30A receptacle.......both feeding a 50A female plug end that you ave plugged into your coach.
Or you using some other adapters to plug this adapter in?
I've seen a 50A male plug end to two 30A female end 'Y' adapters.......each leg of 50A feeds the one leg of 30A........But not the other way around.
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pulsar
Lewisville, NC
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Moved from Forum Technical Support to Tech Issues.
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pianotuna
Regina, SK, Canada
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Hi,
What did the ems say about leg #2?
Plug in the "cheater cord" again and use the volt meter to check the 50 amp female outlet.
Regards, Don
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CA Traveler
The Western States
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It does sound like you are describing the cheater cord, 2 male 30A to a 50A female. To be clear are these 30A RV plugs and not something else. It sounds like at least one is wired to 240V. Sometimes the 30A RV plug is mistaken for a 240A plug like a household washer.
The first thing to do is to determine that 30A plugs are wired for 120V and not 240. Next determine if there is 240 between the 2 hots. This means that the circuit feeding the plugs is a split phase circuit. If not search these boards for cheater cord and be aware of the limitations.
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wa8yxm
Wherever I happen to park
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I agree, it sounds like one of the 30 amp outlets is 240 volt.
The proper wiring is as follows (NOTE I'm not sure which witch is which on the 30 amp plugs so you will have to test)
The round, U or D shaped pin on both 30 amp plugs should go to the similar pin on the 50 amp outlet, measure with multimeter in resistance
One side (Same side on both 30 amp plugs) goes to the flat pin opposite the Ground pin.
The other fla blade on the 30 amp plugs goes to ONE of the two side flats on teh 50,, Just one, not the other, and the same pin on the OTHER 30 amp plug goes to the other (remaining) flat side pin on the 50.
Measure both 30 amp outlets, then plug in and measure the 50 amp outlet using the multi-meter.
NORMALLY I do not recommend those cheater boxes, However you have an "Exception" to the rule as you are plugging into two 30 amp outlets.
YOUR EMS may still complain, depending on how the two park outlets are wired, (It will say 30 amps)
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CA Traveler
The Western States
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Use a 30/20 adapter, household tester and plug in voltmeter to test each plug. You should carry these parts anyway.
You didn't say which PI EMS you have but it saved you! A correctly wired (120V) set of 30A plugs could be wired either split phase or not. If not any device that detects a 50A plug will see the cheater cord as 30A. Load shedding devices will shed at 30A.
If it is split phase then you'll have 30A on each hot leg. It's also possible to overload a 30A neutral which is one reason many CGs don't allow the cheater cord.
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vermilye
Oswego, NY, USA
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I'm just rambling over the possibilities -
You stated that you connected through the EMS to each receptacle individually & it indicated that they were wired correctly. I don't understand why the EMS would show 240V on one leg when they are combined through your adapter unless there is a problem with the adapter. I'd be tempted to carefully check the adapter wiring.
If it isn't being caused by the adapter, and your DVM showed each receptacle to be wired correctly, about all that could cause the problem is a phasing problem. The loss of the neutral could cause high voltage on one leg, but would have shown up when you measured the individual receptacles.
In a normal service, if each receptacle shows 120V between hot & neutral, it is likely they are wired one of these ways -
a. They are on opposite legs and a measurement between the two hots would show 240V. In this case your EMS should think you are connected to a standard 50 amp supply.
b. They are on the same leg and a measurement between the two hots would show 0V. In this case your EMS should think you are connected to a 30 amp supply.
c. Although unlikely, it is possible that they are on different legs of a 3 phase supply, in which case a measurement between the two hots would show 208V. Not sure what the EMS would thing of that, but probably think you are connected to a 50 amp supply.
Those are the only standard results I can think of - There can be all kinds of phasing problems if each receptacle was fed from a different transformer but unless there has been a rewiring of the site that is unlikely.
If you find out, please let us know what caused the problem - it is an unusual one.
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agwill
enosburg falls, vt
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In a correctly wired campground every other pedestal is on a different phase so if you hook up to two different pedestals you will get 220volt between. The only way to get your system to work is to use the 20a duplex plug and one 30a plug on the same pedestal. It is a standard cheater cord that can be bought to do what you want. Most large RV places sell this device.
al
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CA Traveler
The Western States
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agwill wrote:In a correctly wired campground every other pedestal is on a different phase so if you hook up to two different pedestals you will get 220volt between. The only way to get your system to work is to use the 20a duplex plug and one 30a plug on the same pedestal. It is a standard cheater cord that can be bought to do what you want. Most large RV places sell this device. If by different phase you mean split phase then 220V between the 2 hots is exactly what you want. Perhaps you're not aware that a 50A RV plug is 220/120. And if you have 2 30A plugs then you get 30A on each hot leg. As I posted above if 2 plugs are not split phase then rig equipment may limit the total draw to 30A.
Many 20A plugs are GFCI (current code) and will trip with the cheater cord as it should. So there are a number of issues with the cheater cord.
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