The RCMS system consists of one or several RCMS460-D / -L or RCMS490-D / -L residual current evaluators, which are able to detect and evaluate fault, residual and operating currents in earthed power supplies via the associated measuring current transformers. The maximum voltage of the system to be monitored depends on the nominal insulation voltage of the measuring current transformers used in case of busbar systems, or on the cables or conductors that are routed through.
Closed W...AB series measuring current transformers are required to measure AC /DC sensitive residual currents (0...2000 Hz). Six W...AB series measuring current transformers require one AN420 power supply unit. W... (closed), WR... (rectangular) and WS... (split-core) series measuring current transformers are used for alternating and pulsating currents (42...2000 Hz).
The measuring current transformer series can be used in any combination with the measuring channels of the evaluators. Each RCMS460-D / -L and RCMS490-D / -L utilizes 12 measuring channels. Up to 90 RCMS evaluators can be connected via a BMS bus (RS-485 interface with BMS protocol), thereby up to 1080 measuring channels (sub-circuits) can be monitored.
If this product is to be used for personnel, fire or plant protection, the frequency response can be set accordingly. The measured currents can be analyzed for harmonics.