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Author 600V 3Ph GFI Delta
Fred

2007-03-23, 8:25 pm

Hi Group!

Working on trying to provide a solution to implement installing GFI
protection on a 600V 3ph Delta feeder for a welder being used underground in
wet conditions.

Feeder ampacity being asked for is 100A.

Anyone had experience in designing any similar installs?

TIA

Fred


Long Ranger

2007-03-24, 3:25 am


"Fred" <fjxallen@shaw.ca> wrote in message
news:HoZMh.55493$DN.19623@pd7urf2no...
> Hi Group!
>
> Working on trying to provide a solution to implement installing GFI
> protection on a 600V 3ph Delta feeder for a welder being used underground
> in wet conditions.
>
> Feeder ampacity being asked for is 100A.
>
> Anyone had experience in designing any similar installs?
>
> TIA
>
> Fred
>As much of this is around anymore, I would be very surprised if there
>wasn't something "off the shelf" that would work.



operator jay

2007-03-26, 1:25 pm

Not exactly. Your 600V system is ungrounded delta? Does it have
ground fault detection? Shouldn't that protect against ground fault
on this (branch) feeder?

Or when you say delta do you just mean the feeder is 3 phase 3 wire,
though the 600V system is grounded? If so, a 100A MCCB (or fused
switch) w/ GFI trip should do though I would guess the cost between
one thousand and several thousand dollars.


"Fred" <fjxallen@shaw.ca> wrote in message
news:HoZMh.55493$DN.19623@pd7urf2no...
> Hi Group!
>
> Working on trying to provide a solution to implement installing GFI
> protection on a 600V 3ph Delta feeder for a welder being used
> underground in wet conditions.
>
> Feeder ampacity being asked for is 100A.
>
> Anyone had experience in designing any similar installs?
>
> TIA
>
> Fred
>



Fred

2007-03-27, 8:25 pm

Correct .... system is ungrounded and supply is a delta connected secondary
three phase three wire.

Looking for molded case breaker with built in GFI ... are these available?
Manufacturer? Cost?

Fred

"operator jay" <none@none.none> wrote in message
news:gpTNh.30292$zJ1.8073@newsfe24.lga...
> Not exactly. Your 600V system is ungrounded delta? Does it have ground
> fault detection? Shouldn't that protect against ground fault on this
> (branch) feeder?
>
> Or when you say delta do you just mean the feeder is 3 phase 3 wire,
> though the 600V system is grounded? If so, a 100A MCCB (or fused switch)
> w/ GFI trip should do though I would guess the cost between one thousand
> and several thousand dollars.
>
>
> "Fred" <fjxallen@shaw.ca> wrote in message
> news:HoZMh.55493$DN.19623@pd7urf2no...
>
>



operator jay

2007-03-28, 3:25 am

>> "Fred" <fjxallen@shaw.ca> wrote in message
> "operator jay" <none@none.none> wrote in message
> news:gpTNh.30292$zJ1.8073@newsfe24.lga...
>
>

"Fred" <fjxallen@shaw.ca> wrote in message
news:rThOh.80473$DN.33904@pd7urf2no...
> Correct .... system is ungrounded and supply is a delta connected
> secondary three phase three wire.
>
> Looking for molded case breaker with built in GFI ... are these
> available? Manufacturer? Cost?
>
> Fred
>


If your system is ungrounded delta then a breaker with GFI doesn't
sound like the correct animal for you. You should speak with the
service outfit who does servicing on whatever brand of gear you have,
they may be able to recommend something. Maybe a shunt trip breaker
and some residual current sensing / relaying would get you what you
want. What happens, at present, if one ground fault occurs somewhere
on your 600V system? Warning buzzer / lights?

I should mention that I seem to recall that there is an important
difference between a breaker rated 600V 3P (suitable for ungrounded
delta as each pole is rated for 600V from ground) and a breaker rated
347/600V 3P (not suitable for ungrounded delta as poles are rated for
347V from ground).

That sounds like a heck of a welder at 600V 3P 100A. Or is the feeder
just extremely long.


Fred

2007-03-28, 8:25 pm

Yes, was hoping to use a shunt trip breaker with a ground fault sensing
circuit capable of tripping the shunt trip molded case breaker.

Actually the feeder is intended for a bank of about 5 welders working in a
wet environment along with some sump pumps at 3ph 600V.

Trying to put together a bill of material to get this started.

Thanks for sharing your thoughts.

Fred
"operator jay" <none@none.none> wrote in message
news:pOkOh.19415$A53.6796@newsfe13.lga...
> "Fred" <fjxallen@shaw.ca> wrote in message
> news:rThOh.80473$DN.33904@pd7urf2no...
>
> If your system is ungrounded delta then a breaker with GFI doesn't sound
> like the correct animal for you. You should speak with the service outfit
> who does servicing on whatever brand of gear you have, they may be able to
> recommend something. Maybe a shunt trip breaker and some residual current
> sensing / relaying would get you what you want. What happens, at present,
> if one ground fault occurs somewhere on your 600V system? Warning buzzer
> / lights?
>
> I should mention that I seem to recall that there is an important
> difference between a breaker rated 600V 3P (suitable for ungrounded delta
> as each pole is rated for 600V from ground) and a breaker rated 347/600V
> 3P (not suitable for ungrounded delta as poles are rated for 347V from
> ground).
>
> That sounds like a heck of a welder at 600V 3P 100A. Or is the feeder
> just extremely long.
>
>



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