Woodward SEG HighPROTEC MRA4, Device Manual

Page: 453 / 510

TCS-Supervision Module – Trip Circuit Supervision ANSI [74TC]
TCS-Supervision Module – Trip Circuit Supervision ANSI
[74TC]
TCS
The trip circuit is monitored by evaluating the auxiliary contacts of the circuit breaker. The CB trip circuits
inclusive cable can be monitored by two non-grouped digital inputs. If a circuit is broken an alarm is issued. With
this protection module it is assumed that the CB is provided with auxiliary contacts (CB-open and CB-closed),
allocated to the digital inputs.
In Slot 1 has 2 digital inputs, each of which has a separate root (contact
separation) for the trip circuit supervision.
In this case the trip circuit supply voltage serves also as supply voltage for the digital inputs and so the supply
voltage failure of a trip circuit can be detected directly.
In order to identify a conductor-failure in the trip circuit on the supply line or in the trip coil, the off-coil has to be
looped-in to the supervision circuit.
Via the two digital inputs the auxiliary contacts are checked continuously (»I
NPUT
1« and »Input 2«) for
»identity« (both open or both closed). If »identity« is identified, the trip circuit is checked for a possible defect
after a set time delay and if necessary the »TCS.A
LARM
« is issued.
The time delay is to be set in a way that switching actions cannot cause false trips in this module.
EN MRA4 04/09 Page 453