Request help fixing confusing 1960 install; 120/240 1 PH panel fed by 208Y/120 3 PH

Installer

Senior Member
Below is a picture of a 1960 Electrical Installation I am trying to fix without pulling new conductors through a conduit.
We have a 120/240 VAC Single Phase panel in the Field fed by a FA 36100 208Y 120 3 Phase breaker 950 feet away. I think we have 2 120 VAC Hots and a Neutral coming from the Breaker without a Ground Conductor?
Am I correct? Can anyone comment on what's going on here?
The conduit is 950 feet long. Its under a huge parking lot and I don't think we can run new conductors
Can I take the existing conductors and remove them from the 3 phase breaker and convert them from H1, H2 and N to become H, N and G?
This way I will have a Ground Conductor from the source panel.
The problem is I would be on a 120 VAC Single Pole breaker. With the 950 foot run and 6 AWG conductors, will I suffer too much line loss?
Does anyone have any ideal on what my options are? I have more pictures if needed.
I haven't put a meter on the field panel to see what's going on with H1 and H2. Would that help?
Electrical 50.png
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
Looks like your H1 is actually on the neutral lug. Or at least you have it labeled that way. What you have labeled H1 is the neutral and where you have the neutral labeled is where the other hot would go. These Sq D panels can be confusing if you're not careful.

What is the problem now? You mentioned you couldn't pull new conductors, is something not working?

ETA: I do think I see white tape on the conductor for the neutral so that is probably ok.
 
Does look like you have two hots and a neutral, which depending on time of install and location might have been OK.
You need to meter the field panel to know what's there- Is there a N-G bond? it's hard to see where the bare wire on the left of the neutral bar goes. If the feed is/was in pipe, that might have been the EGC.
Voltage drop is entirely dependent on load, so if you only have a 2 amp load.... not much of a problem. What's the actual load.
If that's only 4g, a 100 amp breaker feeding it is too big.
 

Installer

Senior Member
1. The conduit was probably put in about 1980 ? It goes 1000' under a heavily used parking lot that we don't own'. Every time we try to pull new conductors through these old conduits it turns out to be a mess, and if we fail, we have no access to the ground above the conduit
2. I'm hoping to put a120 VAC panel in that follows the Code. To follow the NEC Code, I need a Hot , Neutral and Ground. Can I run them to a 40 A 120 VAC single phase breaker ? I think we're dealing with 4 or 6 AWG conductors.
3. Also is it possible that the Conductors are actually correct? Could they be H, N and G? By the way they actually still make that Panel. I Googled Q06 12L100RB but I can't find a diagram..
 
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Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
1. The conduit was probably put in about 1980 ? It goes 1000' under a heavily used parking lot that we don't own'. Every time we try to pull new conductors through these old conduits it turns out to be a mess, and if we fail, we have no access to the ground above the conduit
2. I'm hoping to put a120 VAC panel in that follows the Code. To follow the NEC Code, I need a Hot , Neutral and Ground. Can I run them to a 40 A 120 VAC single phase breaker ? I think we're dealing with 4 or 6 AWG conductors.
3. Also is it possible that the Conductors are actually correct? Could they be H, N and G? By the way they actually still make that Panel. I Googled Q06 12L100RB but I can't find a diagram..
You still haven't said if what you have works or if there is a problem.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
Not running an EGC with a feed was, at one time, legal. There were stipulations such as, no metal paths between. Your OCPD will trip with a short to ground if you have the panel bonded. If this has been there as long as you say, I wouldn't worry about it as long as the panel is made up right and neutral & EGC bars are bonded, along with the cabinet.
 
I agree with Bill. At the time it was allowed to re-bond the neutral, like a service, for outside feeders. I can see the bonding screw in the picture. Looks fine to me I wouldn't change a thing. Have a milkshake instead.

Yeah you have H1 and N mixed up in the comments on the picture.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Is the conduit feeding the panel metallic? No guarantees after all those years that it still is intact but I'll bet that is where they got the ground from.

-Hal
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
1. The conduit was probably put in about 1980 ? It goes 1000' under a heavily used parking lot that we don't own'. Every time we try to pull new conductors through these old conduits it turns out to be a mess, and if we fail, we have no access to the ground above the conduit
2. I'm hoping to put a120 VAC panel in that follows the Code. To follow the NEC Code, I need a Hot , Neutral and Ground. Can I run them to a 40 A 120 VAC single phase breaker ? I think we're dealing with 4 or 6 AWG conductors.
3. Also is it possible that the Conductors are actually correct? Could they be H, N and G? By the way they actually still make that Panel. I Googled Q06 12L100RB but I can't find a diagram..
Can't be sure but it looks like as mentioned it is bonded and the large maybe #6 is re-identified as a gound conductor not seeming to be associated with a branch circuit and is likely acting as GEC to a ground rod. As others have noted your identifications of H1 and N are reversed, notice white identification tape on your referenced H1. By all appearances panel correctly set up as 120/240 1Ph. Feeder almost looks like #2 CU, would probably be undersized for voltage drop at 1000ft for 100A.
The panel breakers would likely all function if all bonding (looks like it's done), neutrals and the breakers themselves are installed correctly and working. The one that not be fully functioning would be the feeder breaker without the EGC between the remote panel and the feeder panel (should function on overload, but may not on short circuit without the EGC). If no underlying issues, there is no reason to alter or change system or panel from NEC perspective, as was compliant at time of installation.
Is your inquiry mearly academic regarding the installation as is or are you needing expanded service, or other trouble existing?

Added question how is it the feeder runs across some land that doesn't have Right Of Way access to repair? If no ROW your options are limited for fixing or upgrade.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Agree with others. Likely compliant when installed.
Maybe shadowing, but I would suggest looking closely at the H2 termination. Possible overheating due to loose connection.;
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Another thought. This install is sixty years old. Probably overdue for the whole thing to be replaced.

You should probably have an insulation test done of the UG wires. My guess is they will fail.

You might be able to get the UG segment under the parking lot replaced by directional boring and running hdpe conduit if as I suspect it needs replacement. Thus no need to dig up the parking lot.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
Another thought. This install is sixty years old. Probably overdue for the whole thing to be replaced.

You should probably have an insulation test done of the UG wires. My guess is they will fail.

You might be able to get the UG segment under the parking lot replaced by directional boring and running hdpe conduit if as I suspect it needs replacement. Thus no need to dig up the parking lot.
The equipment shown is definitely not 60 years old. The panel interior looks no older than the mid 80s.
 
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