Voltage & Generator Relays

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. We can then quickly manufacture and supply an easy                                                             to install retrofit.

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 introduce the MR-METI31 Directional Relay.

Pin for pin to the original METI 31 P&B can provide a quickly installed product. The MR-METI31 provides the same protection features as the previous METI31 providing directional protection (67) either in 2 phase and earth or 3 phase. Designed and manufactured by our in-house facilities in Manchester using high specification electronics for long-life and high-duty operations. The METI31 retrofit provides a risk-free and cost-effective way to manage equipment obsolescence.

View the Manual from our resources here…  

Marketing re-think fuels export growth at PBSI Group


Manchester-based P&B (PBSI Group) is a leading designer and manufacturer of electrical protection, safety and control technologies for critical infrastructure. Exports make up around 80 per cent of sales, but these were mostly through existing customers and contacts. The business recognised an opportunity to expand its customer base overseas with a new approach to marketing.

Read the full case study on Business Growth Hub here.


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.