Can anyone advise what HV isolation requirements are being used for access to HV GIS switchgear ?
We have 110KV GIS switchgear with a 3 position bus isolator that can either be open, closed or in earth position on the non-bus side.
When in the earth position the earth point is a removable copper...
The younger staff I work with are as confused as hell about phase rotation convention, our original phase rotation test instruments had a needle that rotated anti-clockwise in the direction of the arrow for a,b,c rotation. This is as all us oldies expect to see and also how we draw vector...
Thanks guys,
The transformers are manufactured in China and badged ABB,
they are installed with no protection other than the electronic WTI Hi temp shunt trip and fuses at the 11kv RMU.
I'm fully conversant with tank earth fault protection our 10mva mobile skid transformers have this.
I'll...
We have numerous 1500kva dry type transformers being installed, they do not appear to have the laminations grounded. The steel beam supporting the laminations is grounded but insulated from the laminations.
We've not tested to see if they are grounded but visually they don't appear to be.
