GE P24DM - Psl for Tcs Scheme 3; Trip Circuit Supervision Scheme; Figure 140; Figure 141: TCS Scheme 4

5.3.2 PSL FOR TCS SCHEME 3
Opto Input
V01217
&
*Output Relay
LED
User Alarm
pickup
0
50
0
400
dropoff
Straight
0
0
Latching
*NC stands for Normally Closed.
Figure 140: PSL for TCS Scheme 3
5.4 TRIP CIRCUIT SUPERVISION SCHEME 4
Scheme 4 is identical to that offered by MVAX31 (a Trip Circuit Supervision relay) and consequently is fully
compliant with ENA Specification H7. T
o achieve this compliance, there are eight settings in the OPTO CONFIG
column. Two of these settings (Opto 1 Mode to Opto 11 Mode--dependant on I/O option chosen) must be set to
TCS before the scheme can be used, with any remaining opto-input set to Normal as required.
In the diagram below, Opto-input 1 and Opto-input 2 would correlate to one of the above-mentioned opto-inputs.
V01222
52A
52B
R1
Trip Output Relay
+ve
-ve
Opto A
R2
Opto B
Circuit Breaker
Trip path
Trip coil
Figure 141: TCS Scheme 4
Under normal non-fault conditions, a curr
ent of 2 mA flows through one of the following paths:
a) Post Close Supervision: When the CB is in a closed state, the current flows through R1, Opto A, Contact 52A and
the trip coil.
b) Pre-close Supervision: When the CB is in an open state, the current flows through R1, Opto A, Contact 52B, Opto
B and the trip coil.
c) Momentary Tripping with Self-reset Contact: When a self-reset trip contact is in a closed state, the current flows
through the trip contact, contact 52A and the trip coil.
d) Tripping with Latched Contact: When a latched trip contact is used and when it is in a closed state, the current
flows through the trip contact, Contact 52A, the trip coil, then changing to the path trip contact, R2, Contact 52B,
Opto B and the trip coil.
A current of 2 mA through the Trip Coil is insufficient to cause operation of the Trip Contact, but large enough to
energise the opto-inputs. Under this condition both of the opto-inputs will output logic 1, so the output relay (TCS
health) will be closed and the User Alarm will be off. If a break occurs in the trip circuit, the current ceases to flow,
resulting in both opto-inputs outputting logic 0. This will open the output relay and energise the user alarm.
Chapter 14 - Supervision P24xM
286 P24xM-TM-EN-2.1