Dis board nightmare

James Sutton · Feb 15, 2011

Hello All

Have just ran a new 6mm SWA cable 230v single phase supplying an iverter ACU from a 4th floor dis board to the roof. I am unable to isolate the dis board as it servers computer room power racks so i cannot do a Ze test as i cannot disconect the main earth. Also how do i carry out a ZS at the board i no i need the power on to carry out a Zs/PFC at the dis board but i cannot turn off any outgoing MCBs to other ccts

should i just carry out the ZS/PFC at the board with MCBs to other ccts on. i know i have to carry out ZS at points on my installation. But i think on the schedule of test results it asks for Ze ZS and PFC at the orgin.

They have also used a 24way merlin gerin 3phase board but only taken a single phase supply from the rising busbar what came as abit of a shock when looking at the board as the main switch is a 4pole 125A. but all MCBs on all phase have power but on the switch there only using L1 and there also switching the neutral

Any thoughts please. Nothing has goner right on this job glad when its done should be monday will try and upload some photos

Thanks
James Sutton

Deleted member 9648 · Feb 15, 2011

If it is not possible to carry out Ze and PSC you should note on the cert the reasons......can you not arrange to test out of hours?
No reason why you cant carry out Zs and PSC tests at the DB with final circuits energised,as long as there are no RCD's on the distribution circuit.
The TPN DB will have the 3 phase connections linked....nothing wrong with that as long as the DB is labelled as single phase.

StokieSpark · Feb 15, 2011

Are the servers not on ups? In a fActory I'm working In, I'm allowed 10 mins too isolate the installation before the ups runs out of juice

James Sutton · Feb 16, 2011

There are no RCDs on the dis board. So carrying out an Zs on the board should be ok then? Cant do out of hours either IT wont let us shut the board down as it causes them to much work.

James Sutton · Feb 16, 2011

No only the main comms room PDU is UPS backed. IT are just being a pain about things

telectrix · Feb 16, 2011

so, if there,s a power cut, do they all run round like headless chickens screaming" my pc's gone down, i can't get on facebook. jeezus i'll have to speak to the guy at the next desk instead of sending an email" ?