PBSI Group - Protection Relays

About P&B Protection Relays

P&B Protection Relays design and manufacture a wide range of protection relays for use at both Low Voltage and Medium Voltage.

Protection relays are designed to be installed within switchgear panels and they provide electrical protection by measuring current and voltage in a conductor and opening or tripping the circuit breaker or contactor which feeds the electrical load in a fault condition. This prevents the fault from cascading further into the electrical infrastucture which will cause equipment damage and large scale power outages.

Our products are manufactured entirely at our factory in Manchester.  PBSI has recently invested half a million pounds in a new state of the art surface mount and through hole electronic component assembly and production area. On site production allows us to tightly control quality and manufacture at a competitive pricing level but also we are able to tailor our design when the application requires customisation.


P&B Engineering was established in 1932 and pioneered the development of electromechanical motor overload protection. The P&B Golds relay was regarded around the world for many years as the bench mark for motor protection.


Today our relays are used in over 100 countries world wide: in power stations, distribution networks, oil&gas platforms, oil, gas & petrochemical refineries, water, mining, cement, steel plants, chemical process plants and in many other industrial process controlled operations.