Tap Rule

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Bob,
If it's longer than 25 feet, and it's indoors, how can it be considered a 'feeder tap'?

Is this an industrial establishment? If so, you might be able to use 368.17(B)exception.

I did one of these, and the conductors turned out to be 24 feet 10 inches.

Good luck,
Eric Stromberg, P.E. :)
 
eric stromberg said:
Bob,
If it's longer than 25 feet, and it's indoors, how can it be considered a 'feeder tap'?
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Eric

I don't think it could be.

eric stromberg said:
I did one of these, and the conductors turned out to be 24 feet 10 inches.
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I will be close to that.

To be clear the engineers drawings showed less than 25' between enclosures but that did not take into account the realities of going up over and down between the enclosures.

The facility is a Research Institute, I can not claim industrial.

eric stromberg said:
Good luck,
Eric Stromberg PE
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Thanks, I will need some luck as the plans call for 13 - 4" raceways entering one ATS switch. :shock:

Than five parallel 4" raceways concealed above a crowded suspended ceiling for about 120'

But a challenge is what makes the work satisfying. :)
 
Pierre C Belarge said:
Bob
Is your job a feeder tap, or a service tap?.
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Feeder.

There is an existing 4000 amp 208Y/120 switchgear with a single service disconnect.

There are no existing provisions to get 1600 amps out of the gear. We can not add another section to the end of the gear as the feed trough rating of the last two existing sections are only rated 2000 amps and supply 800 amp feeders already.

If it was a service tap there are certainly length restrictions although no one knows the length except the local inspector. :p

IMO I would expect a service tap to be kept shorter than 5' in this area or it would have to be 'outside the building' per 230.6
 
Bob,
If this is over 25 feet (indoors), running a reduced ampacity conductor (or set of conductors) as a feeder tap is not a code compliant installation. What is your stance on this? Do you get a signed letter from them acknowledging this?

Eric Stromberg, P.E.
 
So far I have never violated the 25' feeder tap rules that I am aware of.

As I said the installation as shown on the drawings I received would have resulted in a feeder tap longer than 25'.

As soon as I saw that I submitted an RFI (Request for Info) to the engineer asking to relocate the equipment.

I do not know what our next step would have been if the engineer did not approve my moving the enclosure closer.
 
Bob,
Thanks, I will need some luck as the plans call for 13 - 4" raceways entering one ATS switch.
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If the runs are short I would be looking at DLO/RHW for the conductors. The decrease in labor for the terminations will often more than cover the increase in the conductor cost.
Don
 
Don thanks that may work for at least one incoming set to the ATS. 8)

I have been curious as to how I will be making up 32 - 600s, 20 - 500s and the associated EGCs. :shock:

The ATS is large but I doubt is will seem large enough once the conductors are in place.

To use that cable I will need compression connectors I imagine.
 
Bob,
To use that cable I will need compression connectors I imagine.
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Yes, and to get the correct connectors, you may have to special order them. However, I have used the next size bigger compression connector and have had no problems. Make sure you use a hydraulic crimper if you try that.Don
 
Don,

A hydraulic tool will be no problem at all, we have a few.

I will give your suggestion serious consideration, again thanks. :)

One set of incoming conductors should only be about 20' to 25' each. This set is not the feeder tap, it is the incoming line from the Standby generator.

Now I want to use that cable for everything. :lol:
 
Bob, With all the time you spend on this forum giving out mostly very good advice/answers; How do you find time to do jobs like this one? :)
 
dlhoule said:
Bob, With all the time you spend on this forum giving out mostly very good advice/answers; How do you find time to do jobs like this one? :)
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Mostly :lol:

Hey it's worth every Penny you paid for it. :wink:

I'll take some pictures so you know I am getting it done. :wink:
 
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