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Commissioning: Overcurrent Protection, Non-directional [ANSI 50P]
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 drop-out ratios; each time 3 x single-phase and
1 x three-phase.
Necessary means:
Current source;
•
Current meters; and
•
Timer.
•
Procedures:
Testing the threshold values (3 x single-phase and 1 x three-phase)
For each test performed, feed a current that 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 contact)
Measure the tripping times at the relay output contact.
Testing the drop-out ratio
Reduce the current to 97% below the trip value and check the drop-out ratio.
Successful test result
The measured total tripping delays or individual tripping delays, threshold values, and drop-out ratios correspond with
those values specified in the adjustment list. Permissible deviations/tolerances can be found in the Technical Data
section.
Eaton recommends measuring the total tripping time instead of the tripping
delay. The tripping delay should be specified by the User. The total
tripping time is measured at the position signaling contact of the breaker
(not at the relay output contacts!).
Total tripping time
Please take the breaker operating times from the technical data specified in
the relevant documentation provided by the breaker manufacturer.
EMR-4000
= tripping delay (please refer to the tolerances of the
protection elements)
+ breaker operating time (about 50 ms)
www.eaton.com
IM02602009E
509
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