Fire Pump Service Conductor Tap Length

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infinity

infinity

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I have a service with a tap ahead of the service disconnects to feed a fire pump service rated switch. What governs the length of the service tap conductor inside of a building?
 
The AHJ :D

I can't see where the fire pump service should be treated differently as far as 230.70(A)(1) is concerned.
That seems to be confirmed by 695.6, but with YOU asking the question I feel I'm overlooking something and am about to learn. :D
 
augie47 said:
The AHJ :D

I can't see where the fire pump service should be treated differently as far as 230.70(A)(1) is concerned.
That seems to be confirmed by 695.6, but with YOU asking the question I feel I'm overlooking something and am about to learn. :D
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I'm just trying to figure out if any of the tap rules in Article 240 apply. 695 is somewhat vague.
 
Am I not correct that Art 240 is for feeder and transformer taps and not service taps ?
Possibly Art 695 is vague in order to be in line with Art 230 :D
 
augie47 said:
Am I not correct that Art 240 is for feeder and transformer taps and not service taps ?
Possibly Art 695 is vague in order to be in line with Art 230 :D
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Yes, that was my thought as well. I have a 4000 amp service and need to install a tap before the mains but the engineer is showing a tap length of about 35'. Also he's undecided on the raceway required for enclosing the tap conductors.
 
infinity said:
Yes, that was my thought as well. I have a 4000 amp service and need to install a tap before the mains but the engineer is showing a tap length of about 35'. Also he's undecided on the raceway required for enclosing the tap conductors.
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Concrete or brick, take your pick. If it's running inside the building that is, up to the disco. Things are a little different if everything, fire pump included, is the the room the service comes into.
 
A lot depends on where the metering is at also, here in the south, on large services, the metering is at the transformer, so the fire pump feeder is tapped there and run directly to a service rated disconnect or controller in the pump room (usually underground or in the slab). But I have found up north the metering is usually in a section next to the main inside the building, so tapping is usually in a section between the meter section and the building main. A disconnect rated above the locked rotor current is installed near the main, then back into the slab to the pump room. I have one to do in two weeks that requires a transfer switch to be installed between this and the new generator tap box (Kirk key main, but automatic on fire pump).
 
Rules are same as any other service disconnect switch unless it is run underground in that case it will consider outside with no length restriction!!!!
 
Here's a photo of part of the switchboard. The incoming utility will be in the crown box section at the top left and the fire pump switch will be at the extreme right with a few more sections in between. The tap will be in the top of the first section on the left. IMO the raceway feeding the switch will need to be in 2" of more of concrete.

1332154930562.jpg
 
infinity said:
Here's a photo of part of the switchboard. The incoming utility will be in the crown box section at the top left and the fire pump switch will be at the extreme right with a few more sections in between. The tap will be in the top of the first section on the left. IMO the raceway feeding the switch will need to be in 2" of more of concrete.

1332154930562.jpg
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Will the Fire Pump disconnect switch be part of the switch gear?
 
With that arrangement I would not doubt the AHJ accepting without the encasement especially if that's a dedicated switchgear room. I see similar accepted in these parts frequently.


side note: Is the duct not a violation ?
 
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DARUSA said:
Will the Fire Pump disconnect switch be part of the switch gear?
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augie47 said:
With that arrangement I would not doubt the AHJ accepting without the encasement especially if that's a dedicated switchgear room. I see similar accepted in these parts frequently.


side note: Is the duct not a violation ?
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FP switch will be a separate 1200 amp enclosure at the right end of the board. Yes, this is a dedicated switchboard room with 2-4000 amp services.

Is the duct a violation? Well it's about 4.5' above the crown box but 6.5' above the actual section of gear. We debated if the 6' clearance is measured from the equipment or the top of the box.
 
I'm not so sure that will fly with the AHJ, I've never seen one done that way, usually the fire pump tap is in the utility pull section, because it is not allowed to be tapped in the same section as the main. The tap conductors are not running through the two 4000 amp sections to the 1200? If it was put in the slab between the tap section and the 1200 amp switch, I think you would be ok.
 
I can not see the issue here!!! Can some body explain to me it? The disconnect switch inside of the electric room will be as any other service switch taped from the load side of the CT's now ,from the disconnect switch inside of the electric room the ( 1200amp ) feeder wire need to meet the 2hrs fire rate or be in a system with two hrs fire rate, you have a few option to do this meeting the requirements for 695.6B. If the issue is the underground part or encase in concrete you have the option of use RHH wire rated 2hrs fire rate with regular EMT pipe (steel fittings) supported every 6 feet with the RHH wire inside.
 
DARUSA said:
I can not see the issue here!!! Can some body explain to me it? The disconnect switch inside of the electric room will be as any other service switch taped from the load side of the CT's now ,from the disconnect switch inside of the electric room the ( 1200amp ) feeder wire need to meet the 2hrs fire rate or be in a system with two hrs fire rate, you have a few option to do this meeting the requirements for 695.6B. If the issue is the underground part or encase in concrete you have the option of use RHH wire rated 2hrs fire rate with regular EMT pipe (steel fittings) supported every 6 feet with the RHH wire inside.
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So you're saying that 30'-35' tap run in conduit overhead to the 1200 amp switch is code compliant under the NEC or is it a NYC thing?
 
DARUSA said:
Actually you right 25 feet is the maximum tap length .Go over it will need underground or encase in a least 2 inch concrete .
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Curious, what Code Article do you use for the 25 ft limit ?
 
Ultimately I will not have much to do with the final installation but was just asking for my own edification. Seems to me that the condcutors feeding this switch will be service entrance conductors falling under article 230. There is no tap rule for SEC's pertaining to this installation unless there is something to do with the 2 hour rated cable that was mentioned.
 
augie47 said:
Curious, what Code Article do you use for the 25 ft limit ?
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Actually when you mention tap I assume that you consider the service wire as a tap conductor in that case the wire have to meet the tap rules. Personally I dont see it as a tap conductor based on 240.2 ,but in the same time overcurrent device (Service Switch) need to be installed near of the point of entry by section 230 of code, now I been involved in installation when the service feeder for the fire pump was probably 30 feet but , it is inside of the electric room and also due to large equipment installed there It have been not other way to intall it .Not an issue with the inspector.But we all knows that pass an inpection doesn't means that the intallation was correct. I used rigid metal conduit for that intallation. The only limit probably is the word near of the point of entry. Sorry if I'm wrong with the section mentioned before but I answer from my phone and no code book avalaible now.
 
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