In an industrial plant, they have a 480/277V feeder to a building from a service in another building. The disconnect in the service is 600A and the feeder is 2 sets of 350kcmils. It feeds a service-rated 600A fused disconnect containing 175A fuses. This disconnect feeds a 480-208 150kVA transformer. Now they'd like to add a 200A 480/277V panel to the building. What would be the least expensive way to tap the 600A feeder to add this panel. I know it'll need a service-rated main and to be grouped with the transformer disconnect...and have a grounding electrode system. But what's the best way to tap the feeder? J-box with lugs? 400A lugs big enough? Do the lugs need to be service rated?
Best way to tap a feeder to a fused disconnect?
- Thread starter donw
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mdshunk
Senior Member
- Location
- Right here.
If I understand your situation correctly, I'd do it with a sufficiently sized junction box and distribution blocks with the appropriate number and sizes of holes.
mdshunk
Senior Member
- Location
- Right here.
Check here:
http://ebusiness.ilsco.com/webapp/w...Id=10001&langId=-1&catalogId=1&categoryId=168
On a quick glance over, it looks like the PDB-49-500-1 would accomodate your pair of 350's on the line side, and whatever you'd want on the load side.
http://ebusiness.ilsco.com/webapp/w...Id=10001&langId=-1&catalogId=1&categoryId=168
On a quick glance over, it looks like the PDB-49-500-1 would accomodate your pair of 350's on the line side, and whatever you'd want on the load side.
The easiest way may simply be to change the fuses and the load side lugs in the existing disconnect. By installing a double barrel lug in the existing disconnect, leaving that disconnect to be your service rated building disconnect, and run a 200 amp feeder to the new panel , distance determined by tap rules, and install a new 200 amp disconect for your transformer. Very little change in the existing wiring and a minimat outage time.
- Location
- Massachusetts
donw said:
Personally I would tap the line side as originally planed but either way can be done.
You need to get some catalogs or at least some web links
Ilsco Stack Lugs
Ilsco Lugs
Ilsco Products
Ideal
T&B
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
- Location
- Massachusetts
LarryFine said:
I have tried to learn to like those.....
For the most part I don't like them to tap say a 4/0 with a 4/0, I would rather go Polaris for that.
Where the piercing taps seem to shine (IMO) is taping a 4/0 with a 6 or a 10 etc.
Personally, I would follow Bob's lead and use stack lugs, but Larry's idea brings a question to mind.
Since we have parallel feeder conductors, if one was to use the "Kub-L-Tap" would you not need to install a tap on each conductor and parallel you tap feeds thus running a minimum of two 1/0s per phase to the switch ?
Since we have parallel feeder conductors, if one was to use the "Kub-L-Tap" would you not need to install a tap on each conductor and parallel you tap feeds thus running a minimum of two 1/0s per phase to the switch ?
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Larry and Bob,
Are those insulation piercing lugs referred to as tiger bites in the field?
An EC told a owner that he would perform a splice energized, if I let him use tiger bites instead of my normal specification of a long "barrel" compression H Tap done de-energized.
Are those insulation piercing lugs referred to as tiger bites in the field?
An EC told a owner that he would perform a splice energized, if I let him use tiger bites instead of my normal specification of a long "barrel" compression H Tap done de-energized.
- Location
- Massachusetts
ron said:
Not that I have heard but we call them 'couple taps'.
I am willing to bet insulation piercing lugs is exactly what he has in mind.
It should go without saying that the instructions say not to install these on live conductors.
Having used these on 4/0 to 4/0 CU connections I can't help but feel they are no where near as good as your H-Tap standard.
Alignment and placement of the conductors seems to be both critical and difficult depending on how much slack you have to work with.
jrannis
Senior Member
- Location
- Fort Lauderdale/ Miami
electricalperson
Senior Member
- Location
- massachusetts
did you ever have any problems with those? i dont really like using any insulation piercing connector like that. id rather use a split bolt or something like thatLarryFine said:
- Location
- Illinois
- Occupation
- retired electrician
Yes, 310.4 will require you to tap both conductors on each phase.augie47 said:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Same here. My most recent application was a fire-suppression up-fit (or is that re-fit?) in a delicatessen kitchen in a super market. The kitchen panel had a shunt-trip main, which was great . . . except for the exhaust fans, their contactor, and the horn-strobe.iwire said:
I needed to grab a pair of 20a circuits (two 120v blowers) and one more for the contactors, horn-strobe, etc., so I decided to tap onto the incoming 250's with about 8' of #4's to a back-fed (and fastened) 60a main in a small panel, well within the tap requirements.
I've also used the Ilsco Kup-L-Tap, Tapping energized is obviously the main feature.
The ones I used in the deli are the B-taps. Those puppies are big! Click the pic:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Shhh!augie47 said:
(In other words, yes, you're supposed to tap paralleled conductors identically.)
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
They certainly fit the description, and they're definitely rated for energized use.ron said:
I'm still here. :wink:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Maybe it should, but what it does say is that, when installing energized, there must be no load. Otherwise, what's the point?iwire said:
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