centeral battery UPS system

[Hawk]

Can an MCB be used instead of an RCBO for a supply to a UPS centeral battery system if the required disconnection times are met?

 

[Pete999]

Don't see why not

 

[Engineer54]

As a matter of interest, what sort of size is this central battery system?? At what point in the that system are you intending to replace the existing RCBO??

 

[Hawk]

If my memory serves me right, it is a 6kVA system that is installed. (by a different company)

Originally I was told by my boss that a 50A supply was needed to the comms room. I installed a 16mm cable protected by a 50A 30mA RCBO.

The engineer who installed the system has now requested that a 32A MCB be put in place of the RCBO as there will be a high earth leakage which may trip the 30mA RCBO.

 

[alanl]

Is the cable surface run or mechanically protected?
You need RCD protection if not.

 

[Knobhead]

As a matter of interest, what sort of size is this central battery system?? At what point in the that system are you intending to replace the existing RCBO??

Methinks it’s a baby. Time for it to grow yet.

 

[alanl]

Further thinking on this - if the earth current is over 30mA, what does the Designer say about the Installation? Surely there is a standard design for these installations?
Now that you know it could be over 10mA earth current, then you need to read 543.7.

 

[Hawk]

The cable is run on tray above a suspended ceiling. It is a 16mm 3 core hi-tuf cable. Single phase. I haven't been speaking to the designer yet. Should see him on Monday.