Advice needed on UPS connection to 3 phase 3 wire system

[Anonymous user]

Hi,

I need some urgent help here, any advice would be greatly appreciated

While using a MGE Pulsar UPS to connect to our system, which uses a 3 phase 3 wire system, we get the "DC bus too high on rectifier" error msg. This subsequently leads to the breakdown and failure of the UPS later. Our configuration is a transformer which steps down incoming 380~500V to 220V/200V and the star point is used as the earth reference in order for the RCCB/ELCB to be effective for the protection requirement. Input to the UPS now currently is 2 phase input, i.e phase to phase 220V

I would like to ask for advice how we should hook up the UPS to the 3 phase 3 wire system, so the UPS will not fail prematurely always. The UPS technician had mentioned the earth reference was also a neutral point, and provided 110V when using this point with a phase.He suggested to use this earth reference with a phase (110V) and a step-up transformer (to step-up from 110 to 220V), which we felt was ridiculous.

Our UPS (MGE Pulsar M3000RT, i.e. rated 3KVA) topology is On-line double conversion with automatic by-pass and power factor correction, really disappointed in it...

Any info or insight would be greatly appreciated, thanks in advance

[Erasmus_apc · Accepted solution]

APC/MGE no longer supports this type of UPS, you will need to call Eaton Electric at 800-356-5794 for support. Sorry for any inconvenience and thank you for using our forum!