- Forces test current to a sinusoid
- Greatly improves timing accuracy when testing
- Wide range of test currents
- High overload capability
- 50/60Hz operating frequency
- High efficiency
- Current monitoring output
- Compact and portable
The 100ADM-F filter unit reduces the level of current harmonics when testing electro-mechanical protection relays. It is designed for use with our range of secondary injection test sets.
All electromechanical protection relays have iron cores that saturate and distort the test current under high overload test conditions. This distortion causes significant errors in the measured trip time of these relays during testing. Distortion of the waveform can be a particular problem with disc induction type over-current and sensitive earth fault relays.
For example, testing a CDG11 disc induction over-current relay without a filter causes significant timing errors. The results below show the errors for a 1.3s 1A CDG11 over-current relay on its 0.5A plug setting, tested at 5A.
The effect of the filtering on the current may be clearly seen in the waveforms below.
The 100ADM-F has nine current ranges covering 0.25A to 100A and is supplied in an insulated case complete with protective cover and carrying strap.
Current Ranges and Ratings
The 100ADM-F has the following ranges:
|Range||Continuous rating||5 min on/ 15 min off|
The unit may be used at either 50Hz or 60Hz, selectable by a switch on the front panel.
The lower ranges (0.25A-50A) are selected by a switch, and the highest current range is selected by a terminal.
A current monitoring output is provided on all the filter units that provides an output of 0-100mA corresponding to the rated current for the range.
Filter Unit Impedance
The table below give the impedance in ohms of the filter unit against frequency on each range.
|Storage||-20°C to 60°C|
|Operating||0°C to 45°C|
|100ADM-F||340mm x 230mm x 330mm||15.6kg|
Current monitor plug and lead