New one on me.
I locked of a 3p 300A supply to a dis board at main switch room. Checked the dis board for dead and started strippng old circuits and breakers out. Cut a T&E and tripped the 6A MCB.
Turns out one of the single phase outgoing circuits feeds switch gear which can choose between 2 feeds from different dis boards, due to a fault it was trying to choose both feeds and hence back feeding to the board I was working on.
No mention of the system on the board or by the client in the site induction.
How far does one go with checking for dead?
I locked of a 3p 300A supply to a dis board at main switch room. Checked the dis board for dead and started strippng old circuits and breakers out. Cut a T&E and tripped the 6A MCB.
Turns out one of the single phase outgoing circuits feeds switch gear which can choose between 2 feeds from different dis boards, due to a fault it was trying to choose both feeds and hence back feeding to the board I was working on.
No mention of the system on the board or by the client in the site induction.
How far does one go with checking for dead?