If you are involved in metering and EPMS projects, you understand that not all specifications are created equal. Electrical distribution specifications often require a lot of thought and effort. Whereas, metering and EPMS specifications have a tendency to be looser on the specifics or outdated altogether.
Governing standards may require metering and EPMS specifications. Subsequently, they are a great way to visually represent all of the hard work that went into the electrical distribution design. Since the metering and EPMS systems are customer-facing, they are a source of both great opportunity and significant risk. Here are some topics to consider when writing or updating electrical metering and EPMS specification.
Ensuring a Solid Baseline Metering Specification
The first step to a complete metering specification is to ensure it adheres to governing standards for the project’s region. Title 24 in the state of California is one example of such standards.
Title 24 outlines a metering system’s minimum requirements based on the size of the distribution system in scope. Meeting minimum requirements for the governing standard allows further definitions for the metering and EPMS system to be added to the specification.
Building Upon the Baseline Metering Specification
Subsequently, once writing metering specifications to meet the governing standards, additional functionality may be added. A clear metering specification defines each load type requirements (switchboards, motor control centers, panel boards, and further distribution equipment).
Additionally, metering requirements are fully fleshed out to include manufacturer options, meter types required per location, and current transformer expectations. For example, if you are including an electrical power monitoring system (EPMS), we recommend considering and listing additional meter capabilities. A further explanation found below.
Covering EPMS Requirements within the Metering Specification
Retrieving data from installed meters is essential for all Electrical Power Monitoring Systems, and as such, communication requirements should be thought out and defined. The typical metering infrastructure uses RS485 cabling for serial connections and Category cabling for Ethernet applications.
Defining communication requirements within the metering spec will help reduce EPMS integration risk, which typically occurs well after electrical contractors have installed the meters.
Including a Well Defined EPMS Specification
With the foundation of metering and communication requirements listed in the specification, it’s time to ensure the EPMS system can leverage the meters. EPMS systems are software and databases running on servers or sometimes desktops.
As a result, it’s essential to identify the intended software for the system in the specification and define hardware that meets or exceeds software requirements.
Most major meter manufacturers offer their own EPMS software brand that “plays nice” with their own brand of meters. For Instance, if the spec defines specific meters, it usually recommends specifying the same manufacturers for the EPMS software. Compatibility between the software and the meters simplifies both the system’s initial integration and long-term support.
With the software and hardware specified, additional system requirements can be listed based on owner needs. Moreover, if customers target certifications such as LEED, precise meter data logging and reporting requirements will be needed. For critical infrastructure that requires close to real-time monitoring, the specification should outline time synch and event recording restrictions.
Finally, the visual representation of the meter data is paramount to any EPMS system. At a minimum, EPMS specifications should outline the expected data being displayed for monitoring by a facility or operations team. A more fully-fledged display section will list the expected displays by site, building, and area.
We Can Help
APT specializes in power monitoring system design, implementation, and service. If you’d like to learn more about establishing a system or updating an existing system onsite for obtaining the data you need, please contact us.
Ken Shaffer, Senior Project Manager APT