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#170848 11/13/07 07:45 PM
Joined: Jul 2005
Posts: 73
S
Member
Well it looks like I have quite a few jobs this year for Christmas decorations.Just curious what some of you may have wired.One job I have this year is erect and power a 50' artificial tree.The total connected load is about 50 amps @ 120 volt.The customer has a 3 phase 5 wire circuit available to use.So I was thinking of using that and a contactor to provide on-off switching for tree lighting ceremony.The question is do I need a gfci.Well who am I kidding of course I need a gfci.Is there a way to wire the gfci to just trip the coil circuit.Anybody got any ideas??

Joined: Oct 2007
Posts: 56
S
Member
All that I can think of would be to place a gfci in each of your three phase conductors with your lights as a load fed from the gfci. You could then use a cord from each gfci plug to power a relay with n.o. contacts in your main control wiring. This would give you 3 gfci plugs, each with it's own n.o. contact (in series) in the control wiring. A ground fault in any phase would kill the contactor power supply and disconnect all phases.

Not sure if this is what you're looking for though, I don't know why you would want all lights to go out because of a problem in one phase.


Shawn.

Joined: Nov 2002
Posts: 456
C
Member
I have heard of flat face GFCIs that have a ring in the back to put your own wire through. I don't know how they would work with 3 phase.

Joined: Mar 2007
Posts: 165
Member
Leviton used to make one like that. I don't know if they still do. I believe it was intended for high amperage, not sure if it could handle 3-phase. The ring was to accomodate a larger transformer than the one used in the 15A and 20A versions.

Last edited by Retired_Helper; 11/14/07 08:10 PM. Reason: Transformer note.
Joined: Mar 2004
Posts: 251
W
Member
I would think it would be better to have a 3 pole contactor to control the on/off and then several GFCI outlets or breakers serving the tree. A single GFCI contolling the whole tree could lead to some time consuming trouble-shooting in event one of the strings of lights develop a ground fault. A few strings on each GFCI would not blackout the whole tree in the event of a ground fault. Robert

Joined: Jul 2005
Posts: 73
S
Member
I think I was making it more difficult than it needed to be.So what plan to do is use a 3 pole contactor.Feed it with a 3 pole 20 amp breaker.Than use gfci adapters on the load side of the contactor.Now I got another job to wire about 150 amps worth of additional decorations.I guess a generator a several miles of extension cord will needed for this one.Temporary wiring provisions would apply.90 days is legal right.

Joined: Aug 2007
Posts: 61
Member
You need something like the Leviton 6895-B It has a coil in the back that you put your wire[s] through. Not sure if it will work on 3phase though.

~Matt


I would rather beg for forgiveness then beg for permission.

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