Capacity

[hhsting]

I have existing 1600A switchboard service and existing 800A switchboard service both 208/120V three phase. Total demand load both is 884A.


Now additional new 500A service switchboard at 480/277V is going to be placed. Demand load is 464A.

So my question is that 230.2(C)(1) what would be capacity requirement 1600A plus 800A or demand load 884A? According to 230.2(C)(1) would additional new 500A service be allowed?

 

[electrofelon]

I have existing 1600A switchboard service and existing 800A switchboard service both 208/120V three phase. Total demand load both is 884A.


Now additional new 500A service switchboard at 480/277V is going to be placed. Demand load is 464A.

So my question is that 230.2(C)(1) what would be capacity requirement 1600A plus 800A or demand load 884A? According to 230.2(C)(1) would additional new 500A service be allowed?

Does it even matter? You are already good to go using (D) different characteristics.

 

[hhsting]

Does it even matter? You are already good to go using (D) different characteristics.

I dont see how difference of characteristics? you can get step transformer 208V three phase to 277/480V three phase from existing utility service?

 

[david luchini]

I dont see how difference of characteristics? you can get step transformer 208V three phase to 277/480V three phase from existing utility service?

480/277V is a different voltage from 208/120V. You are permitted to have additional services with different characteristics.

 

[hhsting]

480/277V is a different voltage from 208/120V. You are permitted to have additional services with different characteristics.

So does this mean building with 480/277V three phase and I have load of 208/120V three phase service or vice versa then this new service would be allowed?? I dont get it one can use customer transformer to achieve this from existing utility?

 

[electrofelon]

So does this mean building with 480/277V three phase and I have load of 208/120V three phase service or vice versa then this new service would be allowed?? I dont get it one can use customer transformer to achieve this from existing utility?

Why don't you try reading 230.2(D)

 

[don_resqcapt19]

So does this mean building with 480/277V three phase and I have load of 208/120V three phase service or vice versa then this new service would be allowed?? I dont get it one can use customer transformer to achieve this from existing utility?

The code will permit two services for that application, however your utility might not. The code does not address the ability to transform the voltages after the service, it very simply says that "Additional services shall be permitted for different voltages.."

 

[Charged]

I’ve attempted using 230.2(D) a few times and the utility shut it down for my applications.

 

[electrofelon]

I’ve attempted using 230.2(D) a few times and the utility shut it down for my applications.

I have brought in a second service of a different voltage to a building, quite a few times. There are some utilities who won't allow it. For example I recently tried for Seattle City light and they said one service per building is their policy. I'm a bit skeptical that is 100% true all the time, as SCL is good at giving conflicting information at different times and different reps.

 

[Charged]

I have brought in a second service of a different voltage to a building, quite a few times. There are some utilities who won't allow it. For example I recently tried for Seattle City light and they said one service per building is their policy. I'm a bit skeptical that is 100% true all the time, as SCL is good at giving conflicting information at different times and different reps.

Curious your thoughts about something I dealt with recently, somewhat related. We were bringing in a new 480/277 3ph 4w service in the parking lot of a commercial building for ev stations. The dispensers were right next to the building and owner wanted lights mounted on the building in that area, wanted to just trench to the exterior wall and run surface mounted conduit for the lights from the new ev service. Would you consider the building to be served by multiple services at that point? The building service was 480v too. The client owns the building as well, not that I think it matters from code standpoint. I realize there are better ways to do this, which is where we are now but I’m curious about the code interpretation. I’ve also dealt with it working on street lighting projects for cities and they’ve wanted to put lights on buildings ( that they also own) from the street lighting service.

 

[electrofelon]

Curious your thoughts about something I dealt with recently, somewhat related. We were bringing in a new 480/277 3ph 4w service in the parking lot of a commercial building for ev stations. The dispensers were right next to the building and owner wanted lights mounted on the building in that area, wanted to just trench to the exterior wall and run surface mounted conduit for the lights from the new ev service. Would you consider the building to be served by multiple services at that point? The building service was 480v too. The client owns the building as well, not that I think it matters from code standpoint. I realize there are better ways to do this, which is where we are now but I’m curious about the code interpretation. I’ve also dealt with it working on street lighting projects for cities and they’ve wanted to put lights on buildings ( that they also own) from the street lighting service.

Yeah that comes up. The code prohibits a building be supplied by multiple feeders or Branch circuits (with a bunch of exceptions) but doesn't seem to prohibit being supplied by a service and a feeder (or a branch circuit and a service).

 

[Charged]

Yeah that comes up. The code prohibits a building be supplied by multiple feeders or Branch circuits (with a bunch of exceptions) but doesn't seem to prohibit being supplied by a service and a feeder (or a branch circuit and a service).

Thanks for reply, going to re-read thru some of these sections to get a better stance on it, alot of times, I just add placard details and labeling to make it as clear as possible what’s going on to anyone working on it later. My understanding was the biggest safety concern that these code sections are trying to deal with, is that you could think you have shut down the building power but still have energized circuits, not sure if that’s a legit safety concern electricians deal with or not.