P&B retrofits provide solutions to the wide variety of instantaneous, inverse-time and definite-time (IDMT) delayed under and over voltage relays as well as neutral voltage displacement, check synchronism and voltage balance functions.

For generators, comprehensive protection is provided from P&Bs existing generator protection relays which are conveniently housed in midos-style cases making them ideal candidates for the quick replacement of the GEC range.

Relays are easily specified by their secondary CT rating – 1A or 5A, the original relay code, the auxiliary voltage and the original relay size.


The VT input of the P&B replacement is suitably rated for direct connection of phase to phase 415Vac.
All relays feature a 16 character 2-line display and are available in either a 70mm or 100mm case.


25 Check Sync

27 Undervoltage

59 Overvoltage

59n Neutral Voltage Displacement

60 Phase Balance


32  Reverse Power

46  Negative Sequence

51v Voltage Controlled

81   Frequency Relay


P&B is a leading UK innovator of electrical protection, safety and control technologies.

Our specialist expertise and unrivalled experience is relied upon in heavy industries throughout the world to ensure the highest levels of safety and performance.