inspectors would you pass this

[69gp]

just left a job where i found a 13,800 pad mount transformer with an aluminum plate over the concrete pad in front of the doors. Removed the cover to see what was there and low and behold 13,800 volt cables lay on top of some 120/208 cables. I know the 120 cables are good for 600v but since this is private property and not utility shouldn't there be a divider since the 2 cables are different voltages and that the low voltage cables are not rated for the higher voltage cable present.

would you guys approve this install and pass the inspection?

aluminum cover over the front of a transformer pit.

13,800 cables enter on the left with the red tracer. all the other cables are 120/208.

another view of the same pit. lot of trash in there also.

there is another pad set up the same way with the aluminum plate but did not open that. figure its going to be the same.

Oxidation already started to eat away at the aluminum in the lower right corner of the cover.

 

[kwired]

In general I don't think there is anything prohibiting these conductors from being in the same enclosure. Certain conditions may change that, like if there were exposed live parts of the HV system in there.

I think it would be a good idea to route the HV conductors so they were further away from the LV conductors, but don't think it is required.

 

[69gp]

In general I don't think there is anything prohibiting these conductors from being in the same enclosure. Certain conditions may change that, like if there were exposed live parts of the HV system in there.

I think it would be a good idea to route the HV conductors so they were further away from the LV conductors, but don't think it is required.

wouldn't this be a violation of article 300.3 c(2) since this does not fall under a manhole as the opening is only 12" wide and its not switch gear. Every pad mount transformer I ever installed always had the primary and the secondary coming up in the bottom of the transformer either separated by a concrete barrier with windows cut out for the conduits or it was an actual vault with a manhole cover you could gain access to the underneath side.

heck if its safe why do they put a barrier between the high and low voltage sides in the transformer.

well it don't look right to me.

thanks for you answer.

 

[GoldDigger]

...heck if its safe why do they put a barrier between the high and low voltage sides in the transformer....

Maybe because if the exposed terminals? I did not see any in the pit.

If you consider the pit to be part of a raceway, the a barrier would be needed unless the secondary wires were also insulated to the MV voltage.

 

[MasterTheNEC]

wouldn't this be a violation of article 300.3 c(2) since this does not fall under a manhole as the opening is only 12" wide and its not switch gear. Every pad mount transformer I ever installed always had the primary and the secondary coming up in the bottom of the transformer either separated by a concrete barrier with windows cut out for the conduits or it was an actual vault with a manhole cover you could gain access to the underneath side.

heck if its safe why do they put a barrier between the high and low voltage sides in the transformer.

well it don't look right to me.

thanks for you answer.

Well maybe that situation is what prompted a change to 300.3(C)(2)(c). The transformer question is answered at least. :angel:

 

[69gp]

Maybe because if the exposed terminals? I did not see any in the pit.

If you consider the pit to be part of a raceway, the a barrier would be needed unless the secondary wires were also insulated to the MV voltage.

I known why they put the barrier in there to keep them separated. just made a stupid comment that should not have said.

I would consider the pit part of the raceway or if not a raceway than a junction of some sorts since you can remove the aluminum cover that is over part of the pit. When the cover is removed than you have access to both the high and low voltage without a barrier between them. To me it seems as if it is a violation. But than I am not an inspector nor a code expert.

 

[MasterTheNEC]

But than I am not an inspector nor a code expert.

Me Either...I just play with this Crap:angel:

 

[Ponchik]

Is that POCO transformer? Ddi POCO install the HV cable? Do they know this is the set up?

Also it does not seem like the aluminum plate is bonded.

 

[69gp]

Is that POCO transformer? Ddi POCO install the HV cable? Do they know this is the set up?

Also it does not seem like the aluminum plate is bonded.

Install was not by POCO. Not sure who did the install but it was done by a private contractor wire pull and termination. This is on private property. And you are correct the aluminum plate is not bonded to anything. But there again its an access cover or would it just be a cover to access the wires below? I am not sure how the transformer is grounded or run underground. Usually the ground is run about a foot around the transformer and out if I am not mistaken about 3' in front of the doors. It does seem as if there could be a potential for that plate to become energized. Plus you need to step right on it to work on the transformer or kneel down on it to get an oil sample..

 

[jaggedben]

there is another pad set up the same way with the aluminum plate but did not open that. figure its going to be the same.

Oxidation already started to eat away at the aluminum in the lower right corner of the cover.

That really doesn't look much like aluminum, way too shiny. But if it is, aluminum doesn't typically corrode away once it's formed an oxidized layer. That picture might be showing some galvanic interaction with steel bolts or screws but it will probably not progress much beyond what is shown, especially if the screws are stainless or replaced with stainless.

 

[69gp]

That really doesn't look much like aluminum, way too shiny. But if it is, aluminum doesn't typically corrode away once it's formed an oxidized layer. That picture might be showing some galvanic interaction with steel bolts or screws but it will probably not progress much beyond what is shown, especially if the screws are stainless or replaced with stainless.

Its defiantly aluminum. There is 8 grades of aluminum rated series as 1xxx up to 8xxx. Each grade has many different grades contained within each series. Some soft, some hard, some corrode fast and others don't corrode at all. I am not smart just found that on the web. But I do drag race and my block is made of billet aluminum along with the rods and the heads are also aluminum.

My whole point with the post was to see what an inspector thought of the area below the transformer where the cable voltages are mixed.

 

[Ponchik]

If I was an inspector I would make sure the aluminum cover is bonded. I would ask the POCO inspectors to see what their thought is on this install.

 

[69gp]

If I was an inspector I would make sure the aluminum cover is bonded. I would ask the POCO inspectors to see what their thought is on this install.

this is not a POCO install. This is on private property and was not done by the utility or power company. If it was than they have there own way of installing equipment. With this being on private property and under the jurisdiction of the local inspector I see it as a violation but its not my call. I was just looking to see what others thought before I bring it up to the owner. The pit is roughly 4'x5' wide 4' deep. There is no way to get in there unless you want to slide into the 12" wide slot in front of the transformer and I know with my size that is not going to happen. Or you could open the transformer doors and climb down that way. If its a raceway or a junction box I thought you could not have the 13800 in with the 600 volt rated wire.

 

[Ponchik]

You can check the city records and see when the project was done, which inspector signed it off.

Also this is from 300.3(C)(2) NEC 2011

(2) Over 600 Volts, Nominal.

Conductors of circuits rated over 600 volts, nominal, shall not occupy the same equipment
wiring enclosure, cable, or raceway with conductors of
circuits rated 600 volts, nominal, or less unless otherwise
permitted in (C)(2)(a) through (C)(2)(e).


a)...
b)...
c)...
d)...


(e) In manholes, if the conductors of each system are
permanently and effectively separated from the conductors
of the other systems and securely fastened to racks, insulators,
or other approved supports, conductors of different
voltage ratings shall be permitted.
Conductors having nonshielded insulation and operating
at different voltage levels shall not occupy the same enclosure,
cable, or raceway.

 

[Cow]

What is the issue? It looks like a million other transformer vaults that have never been a problem? Also, the aluminum cover. Electrically how is that any different than the metal hinged doors that come on the prefabbed vault lids? Those aren't bonded....

 

[kwired]

I should have known to look in a general section like 300:roll:

I can't say I have ever seen transformer that had divider, at least all the way down into any pit, but all the ones I have been around were POCO transformers and were not installed under NEC either. Larger padmounts have divider incorporated in them but below the transformer itself never has a divider.

 

[69gp]

You can check the city records and see when the project was done, which inspector signed it off.

Also this is from 300.3(C)(2) NEC 2011

(2) Over 600 Volts, Nominal.

Conductors of circuits rated over 600 volts, nominal, shall not occupy the same equipment
wiring enclosure, cable, or raceway with conductors of
circuits rated 600 volts, nominal, or less unless otherwise
permitted in (C)(2)(a) through (C)(2)(e).


a)...
b)...
c)...
d)...


(e) In manholes, if the conductors of each system are
permanently and effectively separated from the conductors
of the other systems and securely fastened to racks, insulators,
or other approved supports, conductors of different
voltage ratings shall be permitted.
Conductors having nonshielded insulation and operating
at different voltage levels shall not occupy the same enclosure,
cable, or raceway.

Yes I did make reference to this section before in this thread and I would not consider this a manhole. There is no entrance into the pit. So if following the code (e) would make this a violation. thanks for your input.

 

[69gp]

What is the issue? It looks like a million other transformer vaults that have never been a problem? Also, the aluminum cover. Electrically how is that any different than the metal hinged doors that come on the prefabbed vault lids? Those aren't bonded....

the issue is I was looking for some input as to what others might have to say about the situation. Just because there are are million other transformers out there does not make it right. That could be a lot of work to be corrected. As I stated before this is not a POCO owned piece of equipment they did not install it. It is covered under the 2011 NEC.

 

[69gp]

The picture above is from another transformer that I had to inspect (different job). Notice the 13,800 cable on the secondary side of the pad mount transformer. Again this is a privately owned transformer and not installed or wired by POCO. Just a sampling of unsafe work and people not really caring about their work. And what is going to happen when the cable that is wedged up against the drain valve or sampling port on the backside corner of the transformer.