Projects are required to provide an electrical metering system that measures the instantaneous power usage and the cumulative electrical energy being used by the building. For metering systems that are not provided by the serving utility company, requirements apply based on the service kilovolt-ampere (kVA) rating as specified in Table 130.5-A and stated below:
1. For electrical service rated at any kVA, the meter must be able to measure instantaneous demand in kilowatts (kW) and energy consumed in kilowatt-hours (kWh) for a user-defined period.
2. For electrical service rated more than 250 kVA, the meter must be able to measure historical peak demand in kW.
3. For electrical services rated more than 1,000 kVA, the meter must be able to measure historical peak demand in kW and energy in kWh per rate period.
Utility-provided meters that indicate instantaneous demand in kW and consumption in kWh for a utility-defined period are sufficient to meet the requirements of this section and are not required to measure historical peak demand. If the utility-provided meter does not indicate instantaneous demand in kW and consumption in kWh for a utility-defined period, a separate meter must be installed that provides the full functionality required by §130.5(a) and Table 130.5-A of the Energy Code.
Each electrical service or feeder must have a permanently installed metering system that complies with these requirements. These terms are defined as follows:
1. “Service” is defined in §100.1. of the Energy Code as "the conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premise served."
2. “Feeder” is defined in Article 100 of the California Electrical Code as “all circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.”
This is not a requirement to install meters at the service and at each feeder. Rather, this requirement simply prevents unmetered service or feeder circuits from being installed within a building by requiring that a meter be installed at either the service level or, if not at the service level, at the feeder level.
Healthcare facilities are exempt from the service electrical metering requirement.
Example 8-1: Service Electrical Metering for Fire Pumps
Question:
There is one service to my building. The building fire pump is installed with the power connection tapped to the same service. Do I need to install another meter for the fire pump, in addition to the service metering already provided by the local utility?
Answer:
No, another meter for the fire pump is not required if it is using a service that is already connected to a meter. If it is not using a service that is already metered, then a separate meter may be required.
Example 8-2: Buildings With Multiple Electrical Services
Question:
There are two services provided by the local utility company to my building. Do both services require meeting the service electrical metering requirement?
Answer:
Yes, each electrical service must be metered in accordance with §130.5(a).
Example 8-3: Buildings With Separate Metering for Tenant Spaces 1
Question:
I own a nonresidential building with four tenant units. The building has one service, and there are four sets of meters and disconnect switches, one set for each tenant unit. The meters, which are provided by the utility company, provide the required kW and kWh information, and I intend to use the meters to meet the §130.5(a) requirement. Is this allowed by the regulations?
Answer:
Yes, metering each feeder instead of metering the service is allowed and is intended to address situations where one service feeds multiple tenants.
Example 8-4: Buildings With Separate Metering for Tenant Spaces 2
Question:
I have a building with multiple tenant spaces, and each tenant space is served by separate feeders. There is an individual meter for each feeder. Do I have to install a separate meter at the building service to fulfill the §130.5(a) requirement?
Answer:
No, it is not necessary to install a separate metering system for the service if a) there are individual meters for all the feeders, and b) all the meters meet the metering functionality requirements, based on the building service size, in Table 130.5-A of the Energy Code.
Example 8-5: Buildings With Multiple Tenant Spaces
Question:
I have a building with multiple tenant spaces, and each tenant space is served by a separate feeder. The building has one service with a utility metering system installed. Do I have to install a separate meter for each tenant space feeder to fulfill the §130.5(a) requirement?
Answer:
No, it is not necessary to install a separate metering system for each tenant space feeder if the building service utility metering system meets the functionality requirements in §130.5(a).