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 kVA as specified in Table 130.5-A and stated below:
•For electrical service rated at any kVA, the meter must be able to indicate instantaneous kW demand and KWh for a user-defined period.
•For electrical service rated more than 250 kVA, the meter must be able to measure historical peak demand in kilowatts.
•For electrical services rated more than 1000kVA, the meter must also be able to measure historical peak demand in kilowatts and kWh per rate period.
Utility-provided meters that indicate instantaneous kW demand and kWh for a utility-defined period are sufficient to meet this Section’s requirements, and are not required to measure historical peak demand. If the utility-provided meter does not indicate instantaneous kW demand and kWh for a utility-defined period, then a separate meter must also be installed that provides the full functionality required by §130.5(a) and Table 130.5-A of the Energy Standards.
Each electrical service or feeder must have a permanently installed metering system that complies with these requirements. The terms “service” and “feeder” are both defined in regulation, the first in the Energy Standards and the latter in the California Electrical Code, as follows:
•"Service is the conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premise served", as defined in §100.1 of the Energy Standards.
•“Feeder - 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”, as defined in Article 100 of the 2016 California Electrical Code.
This is not a requirement to install meters both 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, whatever is appropriate for the installation in question.
Example 8-1
Question:
There is one service to my building and 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, it is not mandatory to provide another meter for the fire pump 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
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, it is mandatory to have one service electrical metering for each service in accordance with §130.5(a).
Example 8-3
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 are provided by a local utility company, they provide the required kW and kWh information, and I intend to utilize 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 to multiple tenants.
Example 8-4
Question:
I have a building with multiple tenant spaces and each individual tenant space is served by separate and individual 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 Standards.