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DESCRIPTION OF EQUIPMENT
The CU-Ps is a primary current injection system offering output currents up to 6000A. 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 CU-Ps is ideally suited to primary
current injection, stability testing and circuit breaker testing. In addition, the CU-Ps also offers
direct-reading CT ratio and polarity tests and a 100A secondary injection output.
Two loading units are available, delivering a maximum output current of 5000A or 6000A.
Each loading unit can be configured for series or parallel output to allow for a wide range of
load impedances. For example, the PLU-6k may be configured in series mode to give a
maximum current of 6000A at 6.6V range or configured in parallel mode to give a maximum
current of 12000A on the 3.3V.
The control units are rated at 12kVA for 1 second. All metering is digital. 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 CU-Ps system has a high accuracy timing system, allowing timing tests to be carried out
to a resolution of 1ms. Selection for normally open or normally 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 system in a range of lengths.
WARNING
The CU-Ps and associated loading units are designed to be used on ‘dead’
systems (i.e. no externally supplied voltages are present on the test object).
Under no circumstances connect a CU-Ps to a live system. Always check that
the power to the device under test is off and the circuit is isolated and earthed
before making any connections.