The PCU1 series are medium powered primary current injection systems, from Macey's Electrical , which offers output currents up to 5000A. The system consists of a separate control unit containing all metering and control functions and a loading unit that provides the high current output.
The PCU1-LT and PCU1-SP primary current injection systems are ideally suited to primary current injection, stability testing and circuit breaker testing. In addition, the SP version offers direct-reading CT ratio and polarity tests and a 100A secondary injection output. T&R also offer the higher-powered PCU1-HP and PCU2.
Two loading units are available, delivering a maximum output current of 2000A or 5000A. Each loading unit has three output taps to allow for a wide range of load impedances. For example, the NLU5000 may be configured to either give a maximum current of 5000A on the 2.3V range, 2500A on the 4.6V range or 1250A on the 9.2V range. Additional loading units are also available in order to meet customers’ requirements for stability testing.
The control units are rated at 11.5kVA with a 2 second overload capability of 23kVA using pulse mode. All metering is digital and a memory facility is provided to hold the current reading when the output trips or is switched off. The current is thyristor controlled and is automatically switched off when the device under test trips.
The PCU1 primary current injection systems have a high accuracy timing system, allowing timing tests to be carried out to a resolution of 1ms. Selection for normally open or closed contacts is automatic, and the status of the contacts is shown on the front panel. Timing modes are available to test under and over current devices, re-closers, under and over voltage devices, current trips and circuit breakers. A full range of high current output leads are available to complement the primary current injection system in a range of length.