hot tap rules

[iwire]

Re: hot tap rules

Dave have you been taking grumpy pills lately.

:roll:

I was not trying to hide anything I provided the code section numbers and we are all adults with code books.

Most equipment is rated 75 C other than the cheap plastic junk that you are finding.

That is all we have been trying to point out.

I have to agree with Trevor that before you tell us we are not reading the code you need to take a look at it using Charlies rules of technical reading. It does not say what you seem to think it says.

Bob

 

[websparky]

Re: hot tap rules

Thanks, Bob.
I agree, I have been grumpy lately.
And yes, Charlies rules do make sense!

 

[jbwhite]

Re: hot tap rules

Assuming that I am not going to use any cheezy plastic switches and all other things as I modified in my more recient post. :roll:
Is there any possible way to take this tread further away from my original question?

 

[iwire]

Re: hot tap rules

What was the original question?

Originally posted by jbwhite:
I was there today.
disconnect switches are rated 75 c

OK so that is settled.

Originally posted by jbwhite:
3/0 from an existing sq d I line panel on a 225 amp breaker. To feed tap blocks in a troff.

3/0 CU is at best good for 200 amps, that I-Line breaker should be changed to 200 amps or less.

Originally posted by jbwhite:
First tap to feed a condensing unit rated min ckt amps 52.6. #6 from tap block to fused disconnect, #6 from disconnect to unit.

If you keep the tap length under 10' you could use as small as 6 AWG from the tap to the disconnect.

If the tap is 10 to 25 feet 4 AWG will be required (1/3 of 200 amps) from the tap to the disconnect.

Originally posted by jbwhite:
Second tap to feed AHU. min ckt amps 15.7 #6 from tap block to fused disconnect. #12 from disconnect to unit.

If you keep the tap length under 10' you could use as small as 12 AWG from the tap to the disconnect.

Actually you could use 14 AWG (it's rated 20 amps) from tap to disconnect but you would still need 12 AWG from disconnect to unit because of 240.4(D) and that would just look stupid.

If the tap is 10 to 25 feet 4 AWG will be required (1/3 of 200 amps) from the tap to the disconnect.

Originally posted by jbwhite:
It looks like the original 225 amp breaker is illegal as the sq d web site says that the I line breakers are rated 75c.

Yes I agree.

Originally posted by jbwhite:
Is the #12 and the 20 amp fuses in the 30 amp switch illegal, as they are less than 10 percent of the 225 amp original feeder?

I do not know where you got 10%, taps between 10 and 25 feet have to be one third the rating of the OCPD.

Originally posted by jbwhite:
Is there any possible way to take this tread further away from my original question?

[ January 08, 2006, 04:42 PM: Message edited by: iwire ]

 

[jbwhite]

Re: hot tap rules

Originally posted by iwire:
I do not know where you got 10%, taps between 10 and 25 feet have to be one third the rating of the OCPD.

Here: 240.21 (B) (4)
(4) For field installations where the tap conductors leave
the enclosure or vault in which the tap is made, the
rating of the overcurrent device on the line side of the
tap conductors shall not exceed 10 times the ampacity
of the tap conductor.


The taps are about three feet.