Protective Relays could be characterized as circuit managers with varying degrees of supervisory and control capabilities depending on the complexity and criticality of the circuit. They are designed to recognize abnormal or fault conditions, and to isolate the affected portion or the electrical system. Not only does this allow the unfaulted portion of the electrical system to continue to function normally, but it diminishes the impact of the faulted portion of the system. Changes to power system circuits and the coordination of protective devices can change due to age, loading, environmental impacts, new construction, etc. It is therefore critical that these devices function properly and are appropriately coordinated when they are called into action.
A relay test set (sometimes referred to as a power system simulator) is used by technicians to assess a relay's programming (settings) and ability to respond to simulated fault conditions. This tool mimics varying conditions of the power system and verifies a relay's behavior under both normal, or faulted power system scenarios.
The Doble F2253 Single Phase Relay Test Set is a popular test set used for preventive maintenance. The test voltage is adjustable up to 300 Volts AC or 400 Volts DC at 150 VA continuous power. The maximum current output of the F2253 is 90 Amperes AC and 60 Amperes DC. It features a internal/external start and stop operations and a multi-mode timer. There is also an option to adjust the frequency and phase angle of the outputs for a custom test configuration.
Related electrical test equipment available for rent from Protec:
Editor’s Note: This post was originally published on April, 2012 and has been updated freshness, accuracy and comprehensiveness.