Utilities are generally required to ensure the delivered steady-state voltage is within the limits specified in ANSI C84.1. Persistent under- or over-voltage can result in customer complaints of frequent blown light bulbs, overheated motors, and equipment damage.

Generally speaking, ANSI C84.1 specifies limits of 5% above and 5% below the voltage nominal at the service entrance. For example, with a 120V nominal, these limits would be 126V and 114V, respectively.

Another standard of note is ITIC (formerly CBEMA) standard, intended to be a performance-oriented standard for electronics equipment manufacturers. ITIC specifies more lax limits of 10% above and below the nominal voltage in the case of steady-state voltages.

Whether voltage is within or outside of the specified limits of either standard, one challenge is relaying this information to the customer in a visual, comprehensible, and intuitive way. This paper will discuss how to do this using a Revolution or Guardian recorder, and PMI’s ProVision software to do just that.