Help needed 13,800 Volts

[mbrooke]

Yes and I have been on a job where that was the case.

A 13.8 KV service was run up inside a three story building to the roof where three 4000 amp services where installed.

Nondescript brick building with no names on it but its own substation and a fleet of locomotive size generators outside.

Pretty sure our tax dollars built it.

Sounds like a data center, but one the gov owns. You get all the cool jobs



To the OP, everything you state is done. I however, recommend the 13.8kv be RMC encased in concrete.

Pulling, terminations and the like will have to be done by an expert. MV power requires terminations that use semi dielectric, stress cones, ect that is a science in itself.

The cable is usually EPR 15kv rated cable with a concentric ground shield. If this cable is done properly and the primary is delta (it should be if POCO isn't handling this) interference should be an issue.


I don't know what fire codes dictate but I do know of some places that might require disconnection of the buss ducts or even the 13.8kv feeders during a fire/emergency.



Generally somewhere in the basement is an MV switchgear room where the primaries are metered. The 13.8kv is then run out to different substations. Its not uncommon for larger buildings to run them in a spot network sequence. That means multiple cable circuits to several transformers operated in parallel with network protectors. Generally the transformers are large dry type units. Oil filled vault transformers could in theory be used but local code might say otherwise.



An LV switchgear room next to the transformer room will feed MCC, elevator machine rooms and buss ducts. The buss ducts will be tapped every floor or multiple floors where 600vac or 480 is brought down via dry type units to 120/208.

 

[Fulthrotl]

Just like to thank all for your input.
Yes 13.8 is not for everybody, including me to work on.
That's why I had the questions.
The 13.8 will be done by a H.V. Contractor

ok... it's MV, does not require a sorcerer.

you are gonna have engineered drawings, and most likely
will have GRC, possibly with encasement. large radius
sweeps, and anyone can run GRC and pull feeders. just
don't bend them tightly, and keep the ends capped on
the feeders, and get a cable splicer with certifications
to build your stress cones.

used to be that was a black art, and redoing existing stuff
still is, but new stuff you can use a 3M kit, allow an hour per
cone, and have it tested and certified afterwards.

but it's better to leave the terminations to a certified third party.
most general specifications will stipulate a cable splicer with five
years experience shall do the terminations.

it's your call......