49Z9005A
+
-
CB
Kxx
MICOM P30
52a
Fig. 5-11: Example of trip circuit wiring.
In order to ascertain that the inductive coil current is switched off from the CB
auxiliary contacts, the setting of minimum pulse duration for trip commands
(MAIN: Min.dur. trip cmd. 1 etc.) and close command need to consider the
operating times of the circuit breaker and its auxiliary contacts. Sufficient margin
has to be applied for pulse duration. A common setting is to double operating
time of the circuit breaker, e.g. for a CB trip operation time top of 100 ms, the
minimum trip pulse time should be 0.2 s (see the following figure).
49Z9006A
CB Closed (52a)
top
CB's operating time
tmop= 2*top
MAIN:
Min.dur. trip cmd. 1
Fig. 5-12: Example of trip pulse timing.
This of course also applies to device open/close command outputs operated with
fix (short or long) command duration (e.g. DEVxx Oper. mode cmd. = Short
command).
If the Px30 output contact triggers an auxiliary relay which opens or closes the
CB consecutively, then it should be verified, that the make/continuous/break coil
currents of this auxiliary relay are within the limit values given in Section 2.5.7,
(p. 2-13).
Note: Upon testing such command outputs, the CB (or equivalent auxiliary
components) must not be mechanically locked, so that the auxiliary 52a/b
contact could operate and break the DC current. If the CB has to stay locked,
tripping or closing circuit has to be opened by terminal disconnection or test
switch.
P634
5 Installation and Connection
5-16 P634/EN M/R-42-A // P634‑311‑653
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