The protective loss of excitation relay type RMQ-111D and the over-excitation relay type RMQ-121D form part of a complete DEIF series of relays for protection and control of generators. The relays are type-approved by major classification societies and are applicable to both marine and land- based installations.
Loss of excitation relay type RMQ-111D (ANSI code 40) :
This relay is applied to protect a generator running in parallel with other generators from running as an induction generator due to under-excitation. The RMQ-111D will thus protect the generator against damages caused by excessive heating due to slip frequency current flow, at the same time preventing transfer of reactive load from a faulty generator. The RMQ-111D is especially applied in cases where applying an under-voltage relay for protection does not suffice, because the remaining generators of the system can supply sufficient reactive power to magnetise the faulty generator, thus maintaining the terminal voltage of the generators.
Over-excitation relay type RMQ-121D (ANSI code 40/O)
This relay is applied to protect a generator against over-excitation and will prevent it from generating too high currents in case of heavy inductive loads. The RMQ-121D will thus protect the generator against damages caused by excessive heating of its windings, at the same time preventing transfer of reactive load to a faulty generator.
●Loss of excitation/over-excitation
●Protection of generators
●Single phase measurement
●LED indication of fault/activ. relay
Borna Niroo Karan (Bornika) is the exclusive agent of DEIF in the fields of consultation , sales and distribution of power industry products including Excitation relay products .