The 100A/E Mk3 secondary current injection test set has been designed to give the maintenance and commissioning engineer a large number of facilities in one self-contained instrument.
The unit is portable, compact and simple to use. The mains supply for the unit is either 240V ±10% or 115V +10% -6% at either 50 or 60Hz.
Full load can be obtained at the supply voltage extremes. The current and voltage outputs are independently controlled and metered. The output current and voltage are displayed on large, clear panel instruments. An additional four range CT is provided, extending the ammeter range down to 0-100mA.
All of the outputs are fully isolated by means of double wound transformers.
The timing system on the 100A/E is very flexible, without compromising ease of use. Four modes of operation and two contact inputs are provided allowing for a wide range of events to be timed. Both contact inputs automatically select for normally open or normally closed contacts. Operation of the different timing modes is described below.
Internal start mode starts the timer when the “on” push button is pressed, and stops the timer when the first contact set changes state. This mode is ideally suited to timing over-current relays.
Single contact mode starts and stops the timer on the first and second changes of state of the fist contact set, and dual contact mode starts the timer from the first set of contacts and stops it from the second set. These modes allow reset and re-close times of protective devices to be easily measured.
The final mode of operation of the timer starts the timer when the current exceeds 20% of the selected metering range, and stops it when the current falls below 20%. This allows the timing of trips with no auxiliary contacts such as miniature circuit breakers.
Automatic control has been provided such that all outputs can be switched off once the device under test has operated. The automatic control can be switched in or out of circuit for all outputs, enabling setting up procedures to be carried out.
The instrument is housed in a robust case complete with a protective cover and fold away carrying handles.