Unusual Panel Modification

[J2H]

I saw this unusual setup at transmitter site, I was recently at. Seems questionable at best but other than the double lugged wires, and the design consideration of the top breaker spaces being blocked I can't find think of a definitive code violation. That said, the length of the studs looks a little short and there are possible not enough threads engaged. Curious on the forum's thoughts on this, and if it is something that should be corrected.

 

[ptonsparky]

A genuine CF.
Remove it and replace with proper breakers.
Some panels can utilize feed through lugs, which may be available.
Rules on Taps would apply. YMMV

 

[J2H]

A genuine CF.
Remove it and replace with proper breakers.
Some panels can utilize feed through lugs, which may be available.
Rules on Taps would apply. YMMV

Thanks for the confirmation, it certainly didn't look good to me, or appear to have that feed through arrangement from the factory. The #12 wire feeds a surge suppressor, and the 1/0? feeds a fused disconnect for a transmitter. I was not able to open the disconnect when I was last there to confirm wire or fuse size.

While not code, seems like this was a common install practice, but I have had this have disastrous consequences when the surge suppressors fail, and always recommend correction when I've found this.

Even worse at the same site, there is a surge suppressor directly on the line side of another disconnect for the backup transmitter. There is currently no main service disconnect at this site.

In my mind the best practice would be a 400 amp disconnect to feed the panel, and the 2 transmitter disconnects as taps from conductors in a trough. Seems another option would be parallel 4/0 conductors, and then feed the aforementioned devices from those as taps, and group all three disconnecting means, but that is less than ideal in my opinion.

Along the lines of feed through lugs, it looks like this might be an option depending on loading. https://superbreakers.com/products/square-d-qo3125sl-lug-kit

 

[jim dungar]

While not code, seems like this was a common install practice.....

This is not to code.
The UL Listing of that panel does not include the field addition of lugs on the load side of the main breaker where the panel bussing connects

 

[don_resqcapt19]

A genuine CF.
Remove it and replace with proper breakers.
Some panels can utilize feed through lugs, which may be available.
Rules on Taps would apply. YMMV

Those are SquareD breakers, and that sure looks like SquareD bus to me/

 

[J2H]

Those are SquareD breakers, and that sure looks like SquareD bus to me/

Yes, good eye it is indeed Square D. Somewhat surprisingly to me the transmitter that is fed from the lugs was installed fairly recently. Surprised the installing electrician didn't check upstream of the disconnect prior to wiring the load side. I certainly would have.

 

[jim dungar]

Those are SquareD breakers, and that sure looks like SquareD bus to me/

It looks like a 3-phase QO loadcenter from before the 90s. Most of the breakers are not from the original installation.

 

[ptonsparky]

Remove only the CF. Not the whole panel.

 

[J2H]

It looks like a 3-phase QO loadcenter from before the 90s. Most of the breakers are not from the original installation.

Yep, it does appears that most of the breakers for some reason are not original. Also looks like there is some minor oxidation and replacement is probably in order. I'm guessing this panel is original to the building and dates to the late 60s.

 

[J2H]

Remove only the CF. Not the whole panel.

That sounds like a good plan, posted before I saw this.

 

[J2H]

I'll have to check the actual loading and see if that lug kit will work. Off the top of my head I suspect the load is greater 125 amps. On the installations, I have personally done, I've always sized the wiring and OCPD at 125% of the worse case current based on max power of transmitter, not the actual licensed power. Unusual for these things to change, but there is there is always the possibility of a power increase due to an antenna change etc, and I would like to avoid a unsafe situation that one who is not electrically qualified might recognize.

 

[ModbusMan]

That wire coloration looks more appropriate to a Mardi Gras parade, and while my eyes aren't what they used to be, I think I see a white+green combination going into that top two-pole breaker on the right, and maybe another green fifth from the bottom. Being a transmitter, I'm surprised they didn't use QOB (bolt on) instead of regular QO.

 

[OldBroadcastTech]

Could be even more red-neck

 

[Fred B]

I doubt the lugs used for taps were designed for more than one wire. Also the SD QO panel was not designed for the addition of those lugs. I would say it needs to be corrected. They do make a proper feed thru lug setup for the QO 3 phase:

 

[Fred B]

Could be even more red-neck

Doubt there was an inspection there.

 

[Elect117]

I would double check some of the wiring colors and re-identify where needed.

Some of these have to be MWBC ya? Maybe missing handle ties? I can't count all of the neutrals from the zoomed in photo.

I.E. Right side, 5th from the bottom, is green phase conductor? Blue neutral wire or EGC wire on the top right? Two pole 15A (second from the top right) is white and green phase conductors?

 

[jim dungar]

I would double check some of the wiring colors and re-identify where needed.

Some of these have to be MWBC ya? Maybe missing handle ties? I can't count all of the neutrals from the zoomed in photo.

I.E. Right side, 5th from the bottom, is green phase conductor? Blue neutral wire or EGC wire on the top right? Two pole 15A (second from the top right) is white and green phase conductors?

Green was allowed as a 'hot' conductor up until the early 00s. I would not be surprised to find there are hundreds of thousands of existing 'grandfathered' installations like this.

 

[Elect117]

Green was allowed as a 'hot' conductor up until the early 00s. I would not be surprised to find there are hundreds of thousands of existing 'grandfathered' installations like this.

Would you be allowed to use phase, grounded (neutral) and equipment grounding conductor colors interchangeably back then? Like did you have to stick with one color for each? Or did identification requirements only show up later.


I imagine once someone did some work in the panel they would have re-identified the white / green as a phase conductor to pass inspection?

 

[WD40]

I saw this unusual setup at transmitter site, I was recently at. Seems questionable at best but other than the double lugged wires, and the design consideration of the top breaker spaces being blocked I can't find think of a definitive code violation. That said, the length of the studs looks a little short and there are possible not enough threads engaged. Curious on the forum's thoughts on this, and if it is something that should be corrected.

If no other load changes are needed to the facility all I would do is move the surge suppressor wires to a breaker and clean the busbar then apply some anti oxidant paste to all the breaker stabs as the panel seems to be in a slightly damp or corrosive area.
I'd wager if you IR scan that lug then moved the 1/0 tap to an a official lug kit and IR scan it again it would run much hotter with official lug kit.
As others have noted the 1/0 may be 150A so the lug kit may not even be an option.

 

[jim dungar]

...anti oxidant paste to all the breaker stabs as the panel seems to be in a slightly damp or corrosive area.

The panel bussing is tin plated copper, so what so see is simple tarnish.
QO breakers are shipped with a compound on their jaws. This should be replenished whenever the breakers are moved. Schneider Electric used to sell small tubes of PJC.