frank1972
Member
- Location
- Upstate NY
Hi all,
I am working on a project that includes conversion of an old four story building to apartments and a small restaurant on the first floor. Each apartment will have their own meters, the restaurant will have its own meter and the building owners will have their own meter since the building owners will be responsible for general lighting and receptacles throughout the building, heat pumps on each floor, a rooftop evaporator, elevator, a small laundry room for the residents that contains six washers and six electric dryers and a small exercise facility with three or four treadmills.
My question concerns CT metering of building and restaurant. According to the local electric utility supplier, we may or may not need CT metering depending on the building and restaurant loads. I was under the impression that CT metering is necessary for anything over 200 amps but the utility supplier is saying that for CT metering, load needs to be “at least 108kW or 300A continuous”. The restaurant load was calculated to be 273A @208V three phase (approx 98kW) and the electric supplier is saying that a 320 self-contained meter will handle this load without CT metering.
The building load was calculated to be approx. 362A @208V, three phase. I arrived at this figure by just adding up all the loads of the building such as the heat pumps, laundry appliances, building lighting, exercise equipment, etc. Utility company is saying a CT meter can be used here if its a diversified load.
Question is, can I diversify this building load and if so, how would I go about doing it? I was thinking I could with the mentioned laundry appliances using table 220.54 of the NEC, but can I diversify any other loads? I know the heat pumps will not all be on at the same time but I’m not sure how to tackle this part. Same with building lighting and receptacles.
Also, what exactly is a 320 self-contained meter? Is this something common? I would assume it is a standard meter where the current goes thru the meter as opposed to a CT meter where the current is monitored thru a current transformer.
Thanks for any help on this. I am not getting much help from the utility company on anything here and hoping some of you folks can shed some light on this.
Much appreciated!
Frank
I am working on a project that includes conversion of an old four story building to apartments and a small restaurant on the first floor. Each apartment will have their own meters, the restaurant will have its own meter and the building owners will have their own meter since the building owners will be responsible for general lighting and receptacles throughout the building, heat pumps on each floor, a rooftop evaporator, elevator, a small laundry room for the residents that contains six washers and six electric dryers and a small exercise facility with three or four treadmills.
My question concerns CT metering of building and restaurant. According to the local electric utility supplier, we may or may not need CT metering depending on the building and restaurant loads. I was under the impression that CT metering is necessary for anything over 200 amps but the utility supplier is saying that for CT metering, load needs to be “at least 108kW or 300A continuous”. The restaurant load was calculated to be 273A @208V three phase (approx 98kW) and the electric supplier is saying that a 320 self-contained meter will handle this load without CT metering.
The building load was calculated to be approx. 362A @208V, three phase. I arrived at this figure by just adding up all the loads of the building such as the heat pumps, laundry appliances, building lighting, exercise equipment, etc. Utility company is saying a CT meter can be used here if its a diversified load.
Question is, can I diversify this building load and if so, how would I go about doing it? I was thinking I could with the mentioned laundry appliances using table 220.54 of the NEC, but can I diversify any other loads? I know the heat pumps will not all be on at the same time but I’m not sure how to tackle this part. Same with building lighting and receptacles.
Also, what exactly is a 320 self-contained meter? Is this something common? I would assume it is a standard meter where the current goes thru the meter as opposed to a CT meter where the current is monitored thru a current transformer.
Thanks for any help on this. I am not getting much help from the utility company on anything here and hoping some of you folks can shed some light on this.
Much appreciated!
Frank
