Another trough question

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aftershock

Senior Member
Location
Memphis, TN
Im going to have to replace the service wires from the transformer to this service.
2 of the conduit runs were parallel 3/0 for the 400 amp and 1 conduit for the single run 3/0 for the 200 amp.
Boss feels we can go straight through the trough without making any splices. I feel we would atleast need to bond the neutral(s) in the trough, but
this has also got me thinking this would be like having 2 service drops feeding the same building unless all conductors were spliced phase to phase
at trough then parallel to the 400 amp and single to the 200 amp off of the splice.
 

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Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
Are the conduits in the bottom of the trough for the utility wires? If so how many laterals are you running. I don't believe you can have more than one in this situation. Yes you will need to bond the trough
 

aftershock

Senior Member
Location
Memphis, TN
The reason I brought this up is it looks as if it originally had the servce pass through the trough without splice unless the theives stole the splice blocks too. And the boss thinks we can do it that way, but I feel we will be splicing.
 

Dennis Alwon

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you can run parallel runs but I don't think you can split them up in the meters and bypass the trough splice. All the parallel runs must terminate and originate at the same place. So in the trough they must be connected together and then split to the other meters. I think that would be the way to make it compliant.

They can be in separate conduits but must all be the same lengths and have the same characteristics. Look at 310.10(H) in the 2011. Art. 310.4 in the 2008
 

don_resqcapt19

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Location
Illinois
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retired electrician
you can run parallel runs but I don't think you can split them up in the meters and bypass the trough splice. All the parallel runs must terminate and originate at the same place. So in the trough they must be connected together and then split to the other meters. I think that would be the way to make it compliant.

They can be in separate conduits but must all be the same lengths and have the same characteristics. Look at 310.10(H) in the 2011. Art. 310.4 in the 2008
If they are going to separate meters, I don't see a need to tie all of the service conductors together. They are not in parallel as they are feeding separate loads.
 

don_resqcapt19

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Location
Illinois
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retired electrician
That would then be considered 2 service drops to one structure , correct?
230.2 Number of Services. A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D). For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.
That being said, if the conductors are installed by the utility, the NEC does not apply to these conductors.
 
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masterinbama

Senior Member
The POCO wants me (the EC) to supply the conductors.

Here the POCO has a direct care and control rule. Even if we supply the conductors the NEC does not pick up until the first disconnecting means. No bonding will take place until after the meters.


However, if this was metered as one service with a set of CT's at the transformer, they would have to be joined in the wireway and bonded accordingly before the first disconnect(s).
 

don_resqcapt19

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Location
Illinois
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retired electrician
The POCO wants me (the EC) to supply the conductors.
Here, if we supply the conductors for an underground service the service point would be the secondary terminals on the utility transformer and NEC rules would apply starting at that point. Even if that is the case, the code section I cited would let you terminate each set on its own meter or disconnect without connecting all of the sets together at the trough.
 
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