The control unit may be used with one of two loading
units providing between 5000 Amps or 6000 Amps for five
minutes or up to 10KA or 12KA for short periods. Each
loading unit has two outputs which may be connected in
series or parallel for maximum flexibility. For example,
the LU6000 may be configured to either give a maximum
current of 3000 Amps at 6.6 Volts or 6000 Amps at 3.3
The control and loading units are each housed in tough
steel cases fitted with castors and protective lifting
handles. The loading units have small plan area to allow
them to be positioned as close as possible to the test
object, minimizing power requirements and maximizing the
The PCU2 mk5 control unit is shown here with an LU5000
loading unit. This combination may be used to inject
currents of up to 5000 Amps for 5 minutes, 8000 Amps for
5 seconds or 10000 Amps for 1 second. This unit is
ideally suited to all primary current injection tasks,
including testing under and over current relays, circuit
breakers and CT ratio testing.
The control unit is rated at 20kVA and has digital
metering. A memory facility is provided on the metering
to hold the current reading when the output trips or is
switched off. The current is automatically switched off
when the device under test trips.
A flexible timing system is provided, 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 overcurrent devices, reclosers, under and over
voltage devices, current trips and circuit breakers.