Chaps, thamks for your input.
Zohar - you are right, the lightest loaded of the three conductors carrying each phase has the highest THD ie they are in inverse proportions.
I have reviewed the half hour billing data from the main meter for the whole site now. They have a 1MVA availability from...
I have already used our IR camera and this showed a very slight heating effect on about 4 of the 44 bolts - it was about 6'C higher than ambient.
The cables have been arranged on a galvanised tray structure and are tie wrapped together as individual phases about 2" apart.
One other...
I have a UK site that is supplied by two 415v transformers, each feed to separate sections of a switchboard. A common standby generator can feed both sides through the relevant changeover switchgear upon a power failure.
This board feeds a distribution board via 22 off 240mm2 single cored...
