EDR-5000
IM02602007E
Commissioning: Overcurrent Protection, non-directional [50, 51]
Object to be tested
Signals to be measured for each current protection element, the threshold values, total tripping time
(recommended), or alternatively tripping delays and the dropout ratios; each time 3 x single-phase and 1 x
three-phase.
Especially in Holmgreen connections, wiring errors can easily happen, and
these are then detected safely. Measuring the total tripping time can
ensure that the secondary wiring is o.k. (from the terminal on, up to the trip
coil of the breaker).
It is recommended to measure the total tripping time instead of the tripping
delay. The tripping delay should be specified by the customer. The total
tripping time is measured at the position signalling contact of the breaker
(not at the relay output!).
Total tripping time = tripping delay (please refer to the tolerances of the
protection stages) + breaker operating time (about 50
ms)
Please take the breaker operating times from the technical data specified in
the relevant documentation provided by the breaker manufacturer.
Necessary means
Current source
May be: ampere meters
Timer
Procedure
Testing the threshold values
(3 x single-phase and 1 x three-phase)
Each time feed a current which is about 3-5% above the threshold value for activation/tripping. Then check the
threshold values.
Testing the total tripping delay (recommendation)
Measure the total tripping times at the auxiliary contacts of the breaker (breaker tripping).
Testing the tripping delay
(measuring at the relay output)
Measure the tripping times at the relay output.
Testing the dropout ratio
Reduce the current to 97% below the trip value and check the dropout ratio.
Successful test result
The measured total tripping delays or individual tripping delays, threshold values and dropout ratios correspond with
those values, specified in the adjustment list. Permissible deviations/tolerances can be found under Technical Data.
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