Transfer switch used as service equipment

[copper123]

I am to do some work on a small commercial building in a remote area. They want me to install a 200-amp service on the outside wall and right behind it on the interior wall a 200-amp panel. The area is Government owned and they have requested the service not be metered. For the interim they would like there to be a generator transfer switch so they can run the building with a generator until they provide hard power to the area. After doing some thinking, code hunting, I was under the opinion that I could use the 2 pole, double throw, 200 amp transfer switch as my outside disconnect,( Middle position of switch is Off ) and also as my service equipment. If I put a main, 200 amp breaker inside on my electrical panel, it would act as my over current protection for both the generator or utility loads. The panel would be at the shortest possible point from the outside wall, (right behind the transfer switch) so I am not seeing a problem with this. Anybody see an objection? They have told me that if the ever bring power into the area, the service to the building would be overhead, so I was in the line of thinking that I would put a overhead service drop out of the top of the transfer switch for future use.

Thanks in advance.

 

[suemarkp]

Re: Transfer switch used as service equipment

If the transfer switch doesn't have integral overcurrent protection, then overcurrent protection must be installed immediately adjacent to the transfer switch. I think the implied meaning here is on the same side of the wall, but this isn't crystal clear.

Its also not super clear which enclosure is the disconnect. I belive, from discussions here on this board, that the transfer switch is your disconnect, and you'll need a separate neutral and ground to the panel with the main breaker.

 

[templdl]

Re: Transfer switch used as service equipment

Breaker type transfer switches such as the ones available from C-H are availble with an SE label

 

[copper123]

Re: Transfer switch used as service equipment

I have been reading back through many of the old posts. There is a lot of information on the subject. Unfortunately, the opinions are divided. I have seen many installations were a meter is installed on the outside of a building without a disconnect and the service entrance conductors go through the wall and land on a main breaker in a distribution panel. The Sq D 200 amp MTS is service rated but its still very murky waters. Also, 230.82 kind of throws a curve ball out there. So after more review, it seems like I am more in the dark! Also, 230.91 the statement, "immediately adjacent thereto" IMO implies beside so, by putting my OCPD on the wall behind, I am now not code compliant.

 

[electrofelon]

Re: Transfer switch used as service equipment

Could the DPDT switch be called a meter disconnect switch per 230.82(2)?

 

[Duuuuug]

Re: Transfer switch used as service equipment

Why not just install a SE rated main breaker with a pin/sleeve style generator receptacle mounted to it and install the transfer switch when you install the utility serviceand remove the receptacle

[ April 12, 2005, 01:22 PM: Message edited by: Duuuuug ]

 

[copper123]

Re: Transfer switch used as service equipment

Hi Duuuug,

Yes i suggested something like that, but was told through government appropriations, its a all or nothing kind of affair. Makes pretty good sense if you have ever dealt with the government.
Thanks for the advice.

 

[suemarkp]

Re: Transfer switch used as service equipment

Originally posted by electrofelon:
Could the DPDT switch be called a meter disconnect switch per 230.82(2)?

I think the utility would love this idea. Now the meter spins regardless of whether you are running on utility or generator power! This is assuming you put the switch upstream of the meter, which is what you'd need to do to disconnect the meter.

 

[hess]

Re: Transfer switch used as service equipment

if this is owned by the U S government, you'll need to ask them what they want. because state or local inspectors has no authority over this building.

 

[copper123]

Re: Transfer switch used as service equipment

I agree hess. AHJ comes up a lot on corp/gov work. But, if you ask most all inspectors that inspect that scope of work, they want the installation NEC compliant as well.
Have a good day.

 

[electrofelon]

Re: Transfer switch used as service equipment

I think the utility would love this idea. Now the meter spins regardless of whether you are running on utility or generator power! This is assuming you put the switch upstream of the meter, which is what you'd need to do to disconnect the meter.

Right, put the 'meter disconnect switch' on the load side of the meter - It will disconnect the meter from the building and connect the generator I dont see 'meter disconnect switch' defined in the NEC (the handbook commentary touches on it), so perhaps its open to interpretation.

 

[wyatt]

Re: Transfer switch used as service equipment

could you not treat this as a feeder not a service sence the goverment will bring the power to it. I'v be on a lot of military bases and the buidings or not mettered they use disonect in place of meter cans.