I came upon a question about how a 240V GFI would react. To ask the question, I need to give a little background. There is an adapter for motorhomes to hook up at an rv park to service a 50a motorhome from a combination of a 30a and 20a service. The adapter uses one leg from a 30a 240v service to feed one leg of a 50a 240v recept and one leg from a 20a 240v service to feed the other leg of the 50a recept. The neutrals are apparently tied together as well as the grounds. The adapter states 'will not work on gfi protected plugs.' I know it will trip a gfi, the question is when? Will it trip as soon as the adapter is plugged into the feeder or when there is a load on the recept, i.e. the motorhome?
Operation of a 240V GFCI
- Thread starter vhterway
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GFCI's are supposed to trip because of unbalanced current, so it seems to me there ought to be a load... but more importantly...Why would you have such a get up?
You're feeding a 50 a. plug from one leg of a 20 and a 30 a. recpt???
What's the point of that? I don't see what you're gaining. Do you plug into both and somehow tell which phase is which and then switch the correct ones to the load?
Sounds like a B.S. grinder to me.
edited :
After I posted this it occured to me that it must be some sort of electronic gizmo that turns two power sources into one, in which case if it was going to trip the gfci it might do it immediately.
I'm not sure why it matters whether it does it immediately or not.
You're feeding a 50 a. plug from one leg of a 20 and a 30 a. recpt???
What's the point of that? I don't see what you're gaining. Do you plug into both and somehow tell which phase is which and then switch the correct ones to the load?
Sounds like a B.S. grinder to me.
edited :
After I posted this it occured to me that it must be some sort of electronic gizmo that turns two power sources into one, in which case if it was going to trip the gfci it might do it immediately.
I'm not sure why it matters whether it does it immediately or not.
It doesn't really matter if it trips immediately or not, it was mainly out of curiosity. The purpose of the thing is to allow a motorhome with a 50a requirement to be able to hook up to power where there is no 50a service available, only 30a and 20a. From the looks of the adapter, its just a dumb device that combines two power feeds to get one. I don't know how it makes sure the two legs are on different phases.
ludilo
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If you look at Hubbell Wiring Devices products you will found that in their Marine line they have an "Intelligent Y Adapters" that allow you to connect a 50A, 125/250V from 2 30A 125V receptacles and the Adapters gives you the protection. Maybe you can use the same product on your aplication, it came with different plug configuration (www.hubbell-wiring.com)
vhterway said:
It doesn't seem to me to be a good idea to run something from two seperate breakers.
I guess I can see why you might want a plug adapter of some kind, to be able to use one or the other, but I can't see using both at the same time, because you wouldn't gain any capacity over the circuits you had them plugged into... anything over 30 would trip the 30 and anything over 20 would trip the 20... and just using one or the other probably wouldn't trip the GFCI.
I guess you'd have to label the cords on your ranges, clothes dryers, and air conditioners with numbers like they did on Green Acres
Here's where this whole thing started.
http://www.trailerlife.com/cforum/index.cfm/fuseaction/thread/tid/17374183/srt/pa/pging/1/page/1.cfm
http://www.trailerlife.com/cforum/index.cfm/fuseaction/thread/tid/17374183/srt/pa/pging/1/page/1.cfm
Following your link :
I'd say throw both of these things down over the bank somewhere.
Neither one of these things should be plugged into 220.
If anything in the first picture plugs into 220, it's dangerous.
If the thing in the bottom picture were plugged into a correctly wired recpt. there would be no 220v available in the 125/250 ( 110/ 220) 50 a. recpt.
Reading a few of the accompanying posts in that forum, it sounds like no one is interested in 220 v, and the same phase of 110 is hooked to both sides of the 50 a. plug. Anyone who feels comfortable doing that probably wouldn't be quizzing a forum about it.
The $400 Hubbel thing apparently has some electronics, for which Hubble feels comfortable being liabel.
I'd say throw both of these things down over the bank somewhere.
Neither one of these things should be plugged into 220.
If anything in the first picture plugs into 220, it's dangerous.
If the thing in the bottom picture were plugged into a correctly wired recpt. there would be no 220v available in the 125/250 ( 110/ 220) 50 a. recpt.
Reading a few of the accompanying posts in that forum, it sounds like no one is interested in 220 v, and the same phase of 110 is hooked to both sides of the 50 a. plug. Anyone who feels comfortable doing that probably wouldn't be quizzing a forum about it.
The $400 Hubbel thing apparently has some electronics, for which Hubble feels comfortable being liabel.
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