Polaris Taps in MDP

rugger8008

Member
Location
MIramar
Occupation
Project Manager for C. Davis Electric
Mike this is Bryan Schultz with C. Davis Electric. Ed Davis wanted me to send you a message about an issue that come up today with an inspector. It is regarding polaris taps in an MDP. We have a 600 amp 600v breaker with 4 sets of 350 mcm. We had to polaris tap these 4 sets with 2 sets of 350 to land on the breaker. The inspector says we can not install it that and must install a non-fusable disconnect. He sighted 310.10(H)(2)
 

tom baker

First Chief Moderator
Staff member
Mike hosts the forum, but very seldom answers. We have a very knowledgeable group that answers.
I dont quite follow your post, is this a ten foot feeder tap, does it end in a single OCPD?
Did you tap all the sets of 350s?
A one line would help
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Mike this is Bryan Schultz with C. Davis Electric. Ed Davis wanted me to send you a message about an issue that come up today with an inspector. It is regarding polaris taps in an MDP. We have a 600 amp 600v breaker with 4 sets of 350 mcm. We had to polaris tap these 4 sets with 2 sets of 350 to land on the breaker. The inspector says we can not install it that and must install a non-fusable disconnect. He sighted 310.10(H)(2)
I would want to see a sketch of what you actually did before I was to comment.

I don't quite understand the 4 sets of 350 MCM thing.
 

rugger8008

Member
Location
MIramar
Occupation
Project Manager for C. Davis Electric
Plans called for 4 sets of 350 mcm due to the length of the run. 4 sets of the 350 mcm will not fit on a 600 amp breaker. we used polaris taps and took 2 sets of 350 mcm to the breaker. the taps are 2' from the breaker.
 

dkidd

Senior Member
Location
here
Occupation
PE
Mike this is Bryan Schultz with C. Davis Electric. Ed Davis wanted me to send you a message about an issue that come up today with an inspector. It is regarding polaris taps in an MDP. We have a 600 amp 600v breaker with 4 sets of 350 mcm. We had to polaris tap these 4 sets with 2 sets of 350 to land on the breaker. The inspector says we can not install it that and must install a non-fusable disconnect. He sighted 310.10(H)(2)
You should be able to do it if you have 6 hole units, 4 in and 2 out for each set of phase conductors.
 

rugger8008

Member
Location
MIramar
Occupation
Project Manager for C. Davis Electric
i wish the inspector saw it the same way. He is insisting we need to use a non-fusible disconnect instead of the taps in the MDP
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
i wish the inspector saw it the same way. He is insisting we need to use a non-fusible disconnect instead of the taps in the MDP
I would suggest that the inspector doesn't understand that the two sets of 350mcm and the four sets of 350mcm are Separate Sets of parallel conductors. The requirements of 310.10(H)(2) apply to each set independently.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
i wish the inspector saw it the same way. He is insisting we need to use a non-fusible disconnect instead of the taps in the MDP
Your description indicates that you have met 310.10(H)(2). A non fusible switch obviously has no relation to the price of rice. The inspector is not competent and should be challenged on this as he is obviously wrong. That said, one thing might be an issue is do you have code compliant room for these Polaris taps? I would normally do something like this in a separate J Box near the breaker.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
From what I see is you have parallel service conductor being reduced from 4 sets to 2 sets. As long as the characteristics are the same on the run (before the tap to after the tap) there should not be an issue.

Ask the inspector to join us and read the forum... I would also go above the inspectors head if need be.
 
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