MVAJ 21- Tripping and Control Relays Protection Alstom

Protective relays are precise measuring devices, the contactsof which should not be expected to switch large electricalloads. In some cases, the protective relay may trip a circuitbreaker directly, or according to the coil rating and the numberof circuits to be energized, may do so using a MVAJ trippingrelay. The MVAJ relay interfaces the protection to provide thehigher contact capacity, additional contacts for trippingmultiple circuit breakers, control functions, signalling andinterlocking.The MVAJ range comprises very reliable hinged armaturerelays designed to directly operate circuit breaker trip coils.Built to very high specifications, the MVAJ range provides ahighly flexible and reliable link between the protective relaysand the circuit breakers.KEY FEATURES > Negligible contact bounce > 10 contacts in Midos size 2 case > 20 contacts in Midos size 4 case > Supplied as high burden > Low burden easily selectable by removing an external link > Hand, electrical, hand or electrical and self reset variations > Reset inhibition feature > Delayed cut-off available in high burden applications > AC or DC operation for low burden configuration > 2.5 second time delay MODELS AVAILABLE > Trip relays Trip relays possess a standard hand reset flag and operate within 10ms.Table 1 shows the trip relay versions available. > Control relays Control relay variants of each trip relay are available.These relays possess a following flag andoperate in approximately 15ms.All relays configured for high burden applications are suitable for dc operation only. Customer Benefits
Directly operates circuitbreaker trip coils? High reliability? High speed operation? Immunity to wiringcapacitance discharge AREVA T& D MVAJ 05, 10, 20 Tripping and Control Relays PROTECTION