Trip circuit and Trip Coil supervision Relay Block VAX31NH

Features :-
1. Simple and robust construction
2. Positive action without chatter
3. Choice of pre-closing and post-closing supervision

Benefits :-
1. Trip circuit and Trip coil supervision relay
2. Choice of pre-closing and Post-closing supervision
3. Simple and robust construction
4. Draw out type case
5. Completely dust proof by IP5X class protection

Application :-
Post-closing or continuous supervision of the trip circuit of circuit breakers

This Trip circuit and Trip Coil supervision Relay Block is easily insert in your schematic diagram and connect as you like way.

Two versions of type VAX relay are available. Type VAX 21 and MVAXM 21 relays monitor the trip circuit only when the circuit breaker is closed (post-closing supervision only) while type VAX 31 and MVAXM 31 relays monitor the trip
circuit continuously (both pre-closing and post-closing supervision). Both versions detect the following conditions.
• Failure of trip supply
• Open circuit of trip coil of trip circuit wiring
• Failure of mechanism to complete the tripping operation
Type VAX 21 and MVAXM 21 relays consist of two units. Under healthy condition with circuit breaker closed, both units are energised. If the trip circuit gets open or the trip supply fails, units A drops-off and opens contactA-1 to de-energise unit C. when the circuit breaker is open the auxiliary switch of the circuit breaker shorts contact A-1 to hold-in unit C. Type VAX 31 and MVAXM 31 relays Under healthy conditions with the consist of three units connected as circuit breaker closed, units A and C are energiesed and the operation is the same as that of type VAX 21 and MVAXM 21 relays. When the circuit breaker is open unit B is also energised via the normally closed auxiliary switch of the
circuit- breaker and unit C is held-in by contact B-1 Unit B will detect trip circuit abnormalities with the circuit breaker open in a similar manner as unit A with the circuit breaker closed The C unit in both the versions are delayed on drop-off by means of RC circuit for a total time of 350 to 800 milliseconds, to prevent a false alarm due to collage dips caused by faults in other circuits or during a normal tripping operations, when unit A is momentarily short circuited by the self reset tripping relay contact. If the trip relay fails to reset possibly due to failure of
the circuit breaker tripping mechanism, the alarm is initiated The alarm unit is designed to operate via pilot wires, if required