Hi to all 
I am new to this forum.I am an IT technician with some basic electrical skills.
At my workplace we have 4x 3 phase eaton powerware BladeUPS 12Kva each connected in parallel (3+1 redundant) supplying filtered electricity to production equipment (such as servers and other IT equipment).
Mains > Circuit breaker 1 > UPS > Circuit breaker 2 > Power electrical board > 20amp RCBO's containing circuits to different racks in the server room.
2 weeks ago power to the important production equipment went down. Upon further inspection I found that the UPS's has turned off. I got electricians on site and they realized that the ups powered electrical board also contained 2 air conditioners, a big xerox laser copier printer and 3 offices. Although we never had an overload alarm on the ups (only about 12Kva were being used from the total of 36Kva).
I also found the RCBO belonging to a rack tripped. I am not sure if it tripped when the ups switched off or when power was restored again. This RCBO contains the most equipment connected to it (4.9amps out of max 20 amps). When this rcbo was switched on again it held well and did not trip.
We also found out that the ups earth was not up to par. This was also fixed. A new earth electrode was now in place.
We immediately separated the circuits belonging to the ac's, printer and offices decreasing the load to 8.6Kva. 3 ups units out 4 got damaged in this incident, we are now running on one 12kva ups which should be sufficient until we get a new ups system (which will take some time) . We also balanced the phases as close as possible.
4 days ago the high amp rated circuit breaker between the UPS and the production electrical board tripped. This is a rotary shunt breaker connected with an earth leakage circuit breaker set to 1amp and a delay of 0.5 secs . As I understand if this device trips the circuit breaker, the fault led will light and you have to reset it. But i had to do none of this because it did not indicate any fault.
UPS was still running fine. I switched of all RCBO's and tried to switch the circuit breaker back on. It was not holding on the on position. I opened the circuit breaker enclosure and realized that some components were out place.
I've put them in place and the circuit breaker switched on successfully.
Now I am left worried that the circuit breaker will trip again causing me a lot of problems...Could this have anything to do with the surviving UPS? or the circuit that had its RCBO tripped in the first incident? Defective shunt circuit breaker?
I will appreciate any advice as I am the only person which can offer help at the moment.
Thanks!
I am new to this forum.I am an IT technician with some basic electrical skills.
At my workplace we have 4x 3 phase eaton powerware BladeUPS 12Kva each connected in parallel (3+1 redundant) supplying filtered electricity to production equipment (such as servers and other IT equipment).
Mains > Circuit breaker 1 > UPS > Circuit breaker 2 > Power electrical board > 20amp RCBO's containing circuits to different racks in the server room.
2 weeks ago power to the important production equipment went down. Upon further inspection I found that the UPS's has turned off. I got electricians on site and they realized that the ups powered electrical board also contained 2 air conditioners, a big xerox laser copier printer and 3 offices. Although we never had an overload alarm on the ups (only about 12Kva were being used from the total of 36Kva).
I also found the RCBO belonging to a rack tripped. I am not sure if it tripped when the ups switched off or when power was restored again. This RCBO contains the most equipment connected to it (4.9amps out of max 20 amps). When this rcbo was switched on again it held well and did not trip.
We also found out that the ups earth was not up to par. This was also fixed. A new earth electrode was now in place.
We immediately separated the circuits belonging to the ac's, printer and offices decreasing the load to 8.6Kva. 3 ups units out 4 got damaged in this incident, we are now running on one 12kva ups which should be sufficient until we get a new ups system (which will take some time) . We also balanced the phases as close as possible.
4 days ago the high amp rated circuit breaker between the UPS and the production electrical board tripped. This is a rotary shunt breaker connected with an earth leakage circuit breaker set to 1amp and a delay of 0.5 secs . As I understand if this device trips the circuit breaker, the fault led will light and you have to reset it. But i had to do none of this because it did not indicate any fault.
UPS was still running fine. I switched of all RCBO's and tried to switch the circuit breaker back on. It was not holding on the on position. I opened the circuit breaker enclosure and realized that some components were out place.
I've put them in place and the circuit breaker switched on successfully.
Now I am left worried that the circuit breaker will trip again causing me a lot of problems...Could this have anything to do with the surviving UPS? or the circuit that had its RCBO tripped in the first incident? Defective shunt circuit breaker?
I will appreciate any advice as I am the only person which can offer help at the moment.
Thanks!
