A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
Can Triplex be used for an overhead 3 wire feeder utilizing the messenger as the neutral? This is replacing an existing feeder that utilized three individual conductors.
Overhead Feeder
- Thread starter A/A Fuel GTX
- Start date
- Status
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Do you really mean feeder as opposed to service?
Three wires for a feeder would be one hot, one neutral and one ground.
Triplex for 120/240 service would use the messenger as the neutral with no separate ground, yes?
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
Yes, this a feeder from one building to another. I'm thinking Triplex, 2 insulated ungrounded conductors and one bare grounded conductor. (Messenger). 120/240V. Just not sure if the grounded conductor needs to be insulated.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
The NEC requires an EGC for a feeder. What will you do for that? Triplex is traditionally used for service wiring only.
The neutral must be insulated AFAIK, but the EGC does not need to be.
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
This is replacing an existing 3 wire feeder. It was legal when it was installed years ago.
Cow
Senior Member
- Location
- Eastern Oregon
- Occupation
- Electrician
Triplex is fine, you treat it just like a service.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
consider quadraplex, insulated -- hot, hot, neutral; uninsulated -- geounding
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I am not sure whether that means that you can legally replace that feeder with an identical one which is now non-compliant.
Are you wondering whether you can replace the three insulated wires with two insulated and one insulated because the second configuration was legal that the time of installation? It seems to me that you are running afoul of the provision that following the original code from time of installation must still not decrease the safety of the resulting installation.
So, really you are asking two questions:
1. Is like replacement permitted in a non-conforming existing installation?
2. Does going to an uninsulated neutral decrease the safety of the existing grandfathered installation?
Along the same lines, just as a thought exercise, could you install new knob and tube wiring to replace damaged existing k&t?
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
I am not sure whether that means that you can legally replace that feeder with an identical one which is now non-compliant.
Are you wondering whether you can replace the three insulated wires with two insulated and one insulated because the second configuration was legal that the time of installation? It seems to me that you are running afoul of the provision that following the original code from time of installation must still not decrease the safety of the resulting installation.
So, really you are asking two questions:
1. Is like replacement permitted in a non-conforming existing installation?
2. Does going to an uninsulated neutral decrease the safety of the existing grandfathered installation?
Along the same lines, just as a thought exercise, could you install new knob and tube wiring to replace damaged existing k&t?
OK, so when you do a service change on an old, existing house, you install arc fault breakers? Good luck with that. You will be chasing mixed neutrals forever.
1. Yes and I believe in this case with no parallel paths, it's fine.
2. No, it's done on service entrance conductors all the time.
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
This is an existing feeder. With quad, I'd be splicing the neutral and messenger together, kind of overkill.
- Occupation
- Licensed Electrician
I agree with the bovine member from Oregon.
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