The timing system on the 200A-3PH Mk3 is flexible and exceptionally easy to use, allowing trip times to be measured to a high degree of accuracy. Units with auxiliary contacts may be timed using the NC or NO timer modes, and devices with no auxiliary contacts may be timed using the current operated mode. The unit is ideal for testing the following devices:
- Over and under current relays
- IDMT relays
- Thermal overloads
- Magnetic circuit breakers
The units may also be used in conjunction with the DVS3 Digital Voltage Source to test protection systems requiring three voltages and three currents. Protection that may be tested in conjunction with the DVS3 includes:
- Directional relays
- Distance protection
- Power relays and transducers
The units have three independently controlled outputs, one for each phase. The output is switched on and off by illuminated push buttons, and the current is set using the three control knobs on the front panel. All ranges are continuously variable from zero.
|Range||Continuous||5 minutes||1 minute|
The above intermittent on-times must be followed by an off-time of 15 minutes, and are based on an ambient temperature of 25°C.
Auxiliary AC Outputs
A switched, isolated auxiliary 240V 50mA AC supply is available to power auxiliary control circuits. The output is protected by a fuse.
The output on the 200A-3PH/ED is metered by a digital true RMS system with a 3.5 digit LED display. The range for each channel is independently selected for each channel by a switch on the front panel.
An electronic current trip is automatically set to 115% of full scale of the selected metering range to protect the device under test.
The unit is must be supplied by a 400V±10% 50/60Hz 3 phase 3300VA Max. The optional delta-star supply transformer allows the 400V unit to operate from other supply voltages.
A delta-star transformer is available as an optional accessory for operation from a 3 wire supply.
|Storage||-20°C to 60°C|
|Operating||0°C to 45°C|
The timing system on the 200A-3PH mk3 is very flexible, allowing a wide range of protective devices to be timed.
|Accuracy||0.01% rdg +1d (all except current operated mode)|
|0.01% rdg +3d (current operated mode)|
The contact circuit has an open circuit voltage of 24Vdc and a short circuit current of 20mA. The contacts may be connected to volt-free contacts or contacts connected to a DC voltage system (240Vdc maximum).
The following functions are provided:
|Mode||Timer Start||Timer Stop|
|Internal Start||Press ‘ON’||Contact 1|
|Single Contact||Contact 1||Contact 1|
|Dual contact||Contact 1||Contact 2|
|Current operated||Current > 20% of range||Current < 20% of range|
The output is automatically switched off at the end of the test to safeguard the relay under test.
Protection and Safety
The 200A-3PH mk3 Secondary Current Injection is protected by electronic over current trips on the outputs, fuses on the contact input, the mains input and regulators.
The auxiliary AC output is fuse protected on both units. An earth terminal is provided for connection to a local earth.