Detail SUPERVISION RELAY MVAX 21 ALSTOM
MVAX 12/ 21/ 31/ 91 498
Type MVAX 12/ 21/ 31/ 91: Trip circuit supervision relays
Features
ï ¿ ½ Low burden
ï ¿ ½ Trip circuit can be supervised with
breaker open or closed
ï ¿ ½ Mis-tripping of breaker by
accidental short-circuits avoided
ï ¿ ½ No false alarms given due to
protection operation
Application
The Type MVAX relay supervises the trip
circuit of a circuit breaker, initiating
audible alarm and visual indication if
the trip circuit fails or the mechanism
does not operate.
Four types are available giving
supervision as follows:
Type MVAX 31 gives supervision with
Figure 1 MVAX
the circuit breaker in either state, and
type MVAX 21 with circuit breaker
closed only.
If required, the alarm units of types
MVAX 21 and MVAX 31 can be
operated via pilot wires.
Type MVAX 91, three separate
MVAX 31ï ¿ ½ s in a size 8 case.
