Has there ever been a point (in the last 50 years) where it is code compliant to install 3 conductor service entrance cable to feed a sub panel. Neutral and ground are bonded together. 2 sub panels are fed from a 200 A fused disconnect, they each have a #2 CU SEU cable running from the load side to each sub panel approximatetly 50 ft away.I have always installed 4 wire feeds to sub panels and kept the equipment grounds apart from the grounded(neutral) conductor. BTW this is a single phase 120/240V application. Thanks.
sub panels
- Thread starter nizak
- Start date
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electricalperson
Senior Member
- Location
- massachusetts
i believe it was legal at one point in electrical history. but its also legal to bond the neutral to the case if you run a feeder to a panel in an existing building that doesnt have any metallic paths between the buildings. 250.32 exception.
JohnJ0906
Senior Member
- Location
- Baltimore, MD
I know that it is legal in the '05 NEC for a seperate building, under certain conditions. 250.32(B)(2)
This is no longer legal under the '08 NEC, except existing installations.
This is no longer legal under the '08 NEC, except existing installations.
nizak said:
Because you give no further detail, I'll assume this is all within one building.
Whatever answer you get about what was allowed 50 years ago, if you're doing work in that building, you can ignore those subpanels as being outside of your scope of work, but then you can't run any HRs to those subpanels unless you correct the subpanels. . Correct the subs with 4 wire feeder and grounded / grounding separation or run all new HRs back to the main.
David
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