Ungrounded 240V System
Ungrounded 240V System
(OP)
We are working on an upgrade for an industrial customer with some very old portions of their system. The original distribution was installed in the 30s or 40s and was entirely 240V delta. A few years ago they changed the main service to 480V to feed some newer loads but retained the 240V system by adding a delta/delta 480 to 240V transformer. Much of the distribution is quite old and we will replace the main PDCs and some of the sub-panels but we are considering if anything should be done about the ungrounded system. They have not reported any surge voltage problems but there is that potential and the only ground detection they have is a set of passive ground lights. There are too many 240V, 3-Phase loads to replace the entire system and the transformer is pretty new. Should we consider adding a zig zag HRG to the 240V system or leave it alone as a grandfathered ungrounded system?






RE: Ungrounded 240V System
Does anyone know any shortfalls of a wye/delta grounding system?
Bill
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"Why not the best?"
Jimmy Carter
RE: Ungrounded 240V System
RE: Ungrounded 240V System
RE: Ungrounded 240V System
RE: Ungrounded 240V System
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Ungrounded 240V System
RE: Ungrounded 240V System
" We are all here on earth to help others; what on earth the others are here for I don't know.
" -- W. H. Auden
RE: Ungrounded 240V System
RE: Ungrounded 240V System
Please share your findings on cost comparisons and availability of zig-zag vs. wye/delta grounding schemes.
Thanks.
Bill
--------------------
"Why not the best?"
Jimmy Carter