I have a fire pump that's 480V, my service is 12470 into the building and have to step it down. If I understand 695 requirements, I have to treat the secondary conductors as service conductors and follow the "under the building" protection guidelines from 230.6(1)(2). This fire pump is in the penthouse, does MI cable meet the criteria, and if not any suggestions on how to accomplish this?
Fire Pump Feeds
- Thread starter dholbrook
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rick5280
Senior Member
Re: Fire Pump Feeds
Those requirements are for the service entrance conductors only. The 2002 NEC handbook has drawings in Article 695.5 for transformers. If you install the xfmr at the service equipment, you then have feeders to run up to the fire pump. These would have to be run per Article 695.6(B). These would not be limited to MI.
I'm not familiar with MI cable. Is it a " listed electrical circuit protective system with a minimum 1-hour fire rating " as stated in 695.6(3)? If so, then it would be one of the approved methods.
Rick Miell
Those requirements are for the service entrance conductors only. The 2002 NEC handbook has drawings in Article 695.5 for transformers. If you install the xfmr at the service equipment, you then have feeders to run up to the fire pump. These would have to be run per Article 695.6(B). These would not be limited to MI.
I'm not familiar with MI cable. Is it a " listed electrical circuit protective system with a minimum 1-hour fire rating " as stated in 695.6(3)? If so, then it would be one of the approved methods.
Rick Miell
G
Guest
Guest
Re: Fire Pump Feeds
I went back and read 695.6(A) and (B)again. (A) Service Conductors, refers to supply conductors on the load side of the service disconnect, while (B) is "Circuit conductors" on the load side of the final disconnecting means and overcurrent device(s)". If you are allowed no or one disconnect, why the difference in language?
I went back and read 695.6(A) and (B)again. (A) Service Conductors, refers to supply conductors on the load side of the service disconnect, while (B) is "Circuit conductors" on the load side of the final disconnecting means and overcurrent device(s)". If you are allowed no or one disconnect, why the difference in language?
Re: Fire Pump Feeds
Thanks for the remarks, I hope others will comment as well. I think that MI cable is a good way to comply with these requirements. If anyone has more information on the resistive blanket system, please let me know. I've had quite a challenge working this detail out.
Thanks for the remarks, I hope others will comment as well. I think that MI cable is a good way to comply with these requirements. If anyone has more information on the resistive blanket system, please let me know. I've had quite a challenge working this detail out.
charlie
Senior Member
- Location
- Indianapolis
Re: Fire Pump Feeds
You may be interested in another way to go with this. Check out the Vitalink MC cable. This is a 2 hour UL fire rated power cable.
The makers of the MI cable were blowing a lot of smoke (pun intended) about this product but it is now being built by them as well.
You may be interested in another way to go with this. Check out the Vitalink MC cable. This is a 2 hour UL fire rated power cable.
The makers of the MI cable were blowing a lot of smoke (pun intended) about this product but it is now being built by them as well.
cheryl_massie
Member
I have exactly the same issue on a project. The fire pump is on the 60th floor and the transformer on the 2nd. The AHJ is telling me that 695.6B only applies to feeders from the controller (required to be within sight of the pump) as that is the final disconnecting means and OCPD. He says that the section that applies to my feeder going up the tower is 695.6A - Service Conductors and is requiring concrete encasement.
My question, why would 695.B apply only to feeders from the controller if the controller is in the same room? Has anyone come across this before?
My question, why would 695.B apply only to feeders from the controller if the controller is in the same room? Has anyone come across this before?
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Just a note, please note the date of the original post.
Last edited:
Cheryl,
I have read the article 695.6 again. My understanding is If you have disconnect switch after the transformer on second floor, the conductors before disconnect switch are considered service conductors and the conductors after disconnect switch are considered circuit conductors. 695.6(A) applys to service conductors and 695.6(B) applys to circuit conductors.
The solution to your case is to add one disconnect switch next to the transformer on second floor then you can run a cable listed for this case with minimum 1-hour fire rating to 60th floor.
Please correct me if I am wrong. Thanks.
I have read the article 695.6 again. My understanding is If you have disconnect switch after the transformer on second floor, the conductors before disconnect switch are considered service conductors and the conductors after disconnect switch are considered circuit conductors. 695.6(A) applys to service conductors and 695.6(B) applys to circuit conductors.
The solution to your case is to add one disconnect switch next to the transformer on second floor then you can run a cable listed for this case with minimum 1-hour fire rating to 60th floor.
Please correct me if I am wrong. Thanks.
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