Can this trafo detect IT or TN supply systems automatically. In a IT system both phases supply 115v L1 +L2 = 230v. If I connect the N output jumper J21 to J33 on output side, I Will create an earth fault. When du I need to use this jumper?
Tanks for any help.
Hugh
If you are referring to this link, this only affects the output circuit. There must be a ground for a residual current (or ground fault) circuit breaker to operate. If the output is wired directly to an inverter, with no other connections then the GFCI may be omitted.
Thanks for your reply Mike, I havn’t powered the transformer up yet but will be interested to see what I get on the secondary side when connected to an IT supply I would have expected 115v on both L and N which is why I thought I would create an earth fault if N was earthed. If I am connected to a TN supply with 240v on L1 and 0v on N then I need to create a TN supply on output by connecting the jumper .
GFCI’s work in IT because circuits and equipment are earthed, as in this case it would be the boat. I hope I do not need to check when visiting other harbours in Norway and have to change configeration if necessary. Alle other countries in Europe use TN.
Hugh
Hi Hugh,
The idea of the isolation transformer is to insulate (sic) you from what happens on the shore side. The grounding system on shore side is then independent of the grounding system you use on the yacht. So you don’t need to change anything when the grounding system changes. you need one earth reference connection on the load side of the isolation transformer to make the GFCI work, note not to use one between the transformer and an inverter, but use on the output side of the inverter.
