BE1-50/51B — self-powered overcurrent relay and retrofit kits
BE1-50/51B is a single-phase microprocessor overcurrent relay with time delay (51) and instantaneous overcurrent (50). It is powered by the current of the protected circuit, so no external control supply is needed. The relay is intended for generators, transformers, feeders and motors.
- Type
- single-phase microprocessor overcurrent relay with time delay and instantaneous element
- Power
- from measured current (no external source)
- Applications
- generators, transformers, feeders, motors
- Versions
- BE1-50/51B, BE1-50/51M; A1/S1 cases, horizontal and vertical assemblies
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The relay draws its energy directly from the current of the protected circuit. This removes the need for a control current battery or a separate power unit, which matters for distribution points, remote substations and upgraded switchgear with electromechanical relays. The protection has two stages: a time delay (51) and an instantaneous overcurrent element (50). The relay detects faults accurately both in new facilities and when old devices are replaced. One relay type covers several kinds of connections, including generators, transformers, feeders and motors. Because the relay is single-phase, it is installed on each phase of a three-phase circuit.
The family includes the BE1-50/51B and BE1-50/51M versions. They are produced in various cases, including A1 and S1, and in horizontal and vertical assemblies. Different cases make it possible to fit the relay into existing panel structures. The time delay (51) sets time selectivity between protection stages, while the instantaneous element (50) quickly trips large short-circuit currents. Plug-and-play kits are prepared for installation in a ready cutout, so replacement is done without reworking the panel.
Retrofit is a separate direction. For direct replacement of electromechanical relays of the IAC series (in particular IAC66C and IAC66K), as well as CO and SFC relays, kits and relays that fit existing panel cutouts are offered. Such a replacement reduces the amount of work on the switchboard, because the panel is not reworked and new control supply circuits are not laid. Plug-and-play kits and retrofit cases are available. Some Arc-Flash versions for replacing IAC and CO relays reduce arc flash hazard through accelerated tripping. A shorter arc duration means less energy release to personnel near the switchboard. The acceleration applies to the Arc-Flash versions for replacing IAC and CO relays, not to the whole family.
Self-powered relays are especially useful where there is no stable control current source. For such sites the manufacturer produces ESD-201/202 energy storage devices, which supply breaker trip circuits without a battery. Together with the self-powered relay, this gives a protection scheme without a separate control power source.
Technical specifications
| Type | single-phase microprocessor overcurrent relay with time delay and instantaneous element |
|---|---|
| Power | from measured current (no external source) |
| Applications | generators, transformers, feeders, motors |
| Versions | BE1-50/51B, BE1-50/51M; A1/S1 cases, horizontal and vertical assemblies |
| Retrofit | replacement of IAC/IAC66, CO and SFC relays; arc flash reduction version |
Request a price and lead time
BE1-50/51B — self-powered overcurrent relay and retrofit kits. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
Does the BE1-50/51B need external power?
No, the relay is powered by the current of the protected circuit, so it works where there is no stable control current source.
Which electromechanical relays can be replaced with retrofit kits?
IAC series relays, in particular IAC66C and IAC66K, as well as CO and SFC relays. The new relays are installed in the existing panel cutouts.
What supplies the trip circuits if there is no battery?
ESD-201/202 energy storage devices are produced for this purpose. They supply the breaker trip circuits without a station battery.
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