| PeterD email@example.com posted to sci.electronics.design:
|>>The existing (old) sub-panel is fed by 2 phases and an uninsulated
|>>neutral conductor. There is no ground bus, return conductor to the
|>>service entrance, nor connection to a ground rod. The conductors are
|>>in conduit when leaving the main panel and arriving at the
|>>sub-panel, but not in between (they're stapled to the flat roof
|>>under the roof's insulation & paper).
|> You are kidding, right? Run, run away fast... Totally replace the
|> existing setup, get those wires off the roof!
|>>I want to replace the sub-panel with a modern one with safe breakers
|>>and add a ground conductor, which will be run via another route (I
|>>want to keep the project manageable, so don't want to run new
|> The current system is a hazard, and needs full replacement. If you
|> touch it, do it right. If you don't do it right, and later there's
|> an accident (and there *will* be) you will be held responsible.
|>>Since the neutral conductor is uninsulated, it is in contact with
|> No, that is not an neutral conductor. It is a ground conductor.
Would you like to try to convince anyone? It fits the description of
a grounding conductor installation. The fact that it is (improperly)
used as a neutral conductor doesn't change the way it is installed.
|>>sub-panel (it is in the conduit bringing the feed conductors into
|>>the sub-panel). In a sub-panel the neutral and ground are not
|>>supposed to be connected.
|>>My question is this:
|>>How do I install this new sub-panel and new ground conductor such
|>>that the neutral and ground are separate?
|> Install it according to code. There is no other alternative.
| That is the question. Exactly how to apply the code, no where enough
| enough information has been supplied yet to answer that question.
This is common on Usenet (not enough info). The simple answer is that
everything new must comply with the code. In many ways, such compliance
requires considering what the existing wiring is (how it is installed,
not how it is improperly used). A _new_
sub panel may have to treat
the uninsualted feeder conductor as a grounding wire.
|> includes getting that non-code, hazardous, existing wiring under the
|> roofing removed, and replaced with soemthing that meets code.
| Part of my point exactly; it may well be to Code by "grandfathering".
| Making modifications can be extremely touchy. That is one of the
| reasons i have the the current NEC (2005) as my personal property.
It could be grandfathered by leaving it alone. If the existing sub panel
has space to add new circuits, they _may_
be able to be added. But new
meet current code when installed. And such installation
requires doing things in certain ways that may not be available. The big
thing is there is NO NEUTRAL AVAILABLE at that sub panel right now. There
is a mis-used grounding wire. So a new circuit would have no _legal_
of neutral connection, limit such new circuits to line-to-line 240 volts.
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
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