You cannot post a reply to this discussion. If you have a question start a new discussion
What earthing arrangement is this?
Former Community Member
The supply is from a private transformer in a four core cable 3ph + n. The cable armour is earthed and connected to the MET. However there is also a green and yellow cable connected to the neutral terminal at the main isolator going back to a the transformer casing. The transformer is only 5 or 6 metres away. I think this must have been intended to make it a tncs supply but seems to me to just create parallel neutral conductors. Or is it tn-s-c-s? I have only been able to go off visual inspection because I could not disconnect the supply..
TN-S surely - it's a single consumer from the TX LV
All that's happened is that the single N-E bond has been expressed to the offloading switchboard (usually to keep the N-E offset voltage low for the consumer) - rather than as draw in in the textbooks as being made at the transformer spill box
TN-S surely - it's a single consumer from the TX LV
All that's happened is that the single N-E bond has been expressed to the offloading switchboard (usually to keep the N-E offset voltage low for the consumer) - rather than as draw in in the textbooks as being made at the transformer spill box
