External Maintenance Bypass Switches for UPS Systems

If you are operating a UPS system, then having an External Maintenance Bypass Switch (EMBS) allows your critical power system more flexibility while maintenance is carried out on the UPS system. This allows you to safely keep the equipment online without interruption to the load.

Our range of maintenance bypass key-switches aims to offer key control to improve not only the safety aspect of bypass switching but ensuring only authorised personnel are able to use the switch when required thus maintaining the integrity of a sound UPS and maintenance system.We specialise in 1 to 4 pole, 2 to 4 position UPS bypass switches. Additionally we build rotary cam switches and reverse star delta switches, designed to customer specifications.

All of our products are manufactured to the highest standard using the superior quality materials from Germany. Ranging up to 1200 Amperes, our MBS units are the first and last word in electrical safety and control.

Options Include:

Maintenance Bypass switches supplied as:

1. Switch only

2. Switch in enclosure (plastic or metal or rack mount)

3. Switch in enclosure, wired to to terminals


1. Mechanical (push button) interlock with auxiliaries. This requires that the button be depressed in order to operate the switch.

2. Key interlock.

3. Electrical (solenoid) interlock with auxiliaries. This requires the switch to be in predetermined set electrical 



conditions before the switch can be made operational.

UPA3/100E/Z31/H11 sie mounted in a 400x400x300mm metal eclosure. Note: May be front mounted

UPA3/100E/Z31/H11 side mounted in a 400x400x300mm metal enclosure. Note: May be front mounted