One Line Distribution Diagram

[mkinnes]

I would like to get information on drawing a one line diagram for the power company. The customer wants to get rid of an older 250 volt Delta service and have a 480 volt wye service installed. The largest load demand will be a 50 amp elevator and any air conditioning equipment(in process of getting loads determined.) The rest of the loads will be basic lighting and power for an office space.

 

[l3city]

ok, get current peak demand from util company. Make sure exist. equip to remain (i.e cb's, fuses, etc) is compatible with new equip. Add any new load to the existing peak load. See NEC 220.35

 

[l3city]

ooops, I miss it, since changing voltages, than possible introduction of XFMR to operate existing 240V equipment,

 

[mkinnes]

Well everything has been disconnected except for some temp lighting and a couple temp receptacles. Entire building has been stripped clean(used to be old knob and tube "no insulation"). Customer has elevator installed and wants power for it. tehe...asked me last minute and even though I've installed a bunch of 480 volt services I've never actually set it up diagramatically to justify loads for the power company.

 

[mkinnes]

Well I've talked to National Grid (power company) and it looks like I'm going to need a drawing in autocad format. Anyone know a drafter in the Rhode Island or Massachusetts area?

 

[waross]

If you are installing temporary power for elevators and temporary construction lighting and aplly for a temporary construction service that is one thing.
If this is to be a permanent service to supply the future offices, you may be better to look for a consulting engineer who will work with you. Such a arangement may work to your advantage now and in the future. An independant engineer may be willing to do your design on this project (for a fee), and call you when he runs into a consulting job which requires the services of a contractor.
respectfully

 

[mkinnes]

Well looks like everything is set. I drew up a one line and had it transfered to computer by a co-worker. Power company should be out to look at the site and what it will take to swap transformers next. Hoping they'll be able to do it reasonably quickly but time will tell.