Wiring through Service Disconnects

[TomFitz]

The photos listed below show service disconnects that a subcontractor has installed to bring power to a newly installed boiler (15 million BTU's) in a boiler plant.
They originally had one line coming to one service disconnect and then to the boiler panel and supplying power to 3 contactors (burner motor-air compressor and oil pump motor).. jumpering from contactor to contactor. This was worng according to the manufacturers installation instructions, which mandates a seperate service disconnect for each unit.
To rectify this, they have left that main feed line in place at the service disconnect, installed two more service disconnects next to it, and on the line side, jumpered from service disconnect #1 to #2,.. then from #2 to #3.
(see photo below)
Is this allowable by code? I have searched through NEC 2002 but have not found anything that may address it.

Thank you for any assistance..

Tom Fitzgerald
Savannah, Ga.

Also

 

[TomFitz]

Oh yes.... I forgot to mention,.. although it may be obvious from the photos,..
The load side of the two service disconnects that were added were then brought back through the first disconnect and out to the boiler panel..

Thanks for any input...

Tom

 

[dpc]

There are several issues to consider:

Lugs must be listed for the number/size of conductors installed.

Enclosure must provide sufficient bending space for the size/quantity of wires installed.

Conductor must be protected by upstream overcurrent protective device or fall under appropriate tap rule conditions.

I don't believe that the jumpering on the line side of the disconnects is, in and of itself, a Code violation.

However, wiring a load side conductor through a foreign disconnect enclosure would be a violation unless there is adequate space in the enclosure. See 312.8.

 

[REDDOG]

Somebody really had to fight this installation.
What is the purpose of the unfused disconnect switch?
Lugs must be listed for the number/size of conductors installed, cannot put 2 conductors under same screw. See UL White Book and Article 110.
Carries grounding conductors for branch circuits, but I did not see grounding conductor from main feeder.
A wireway above the switches would make the problems go away.

 

[MakeItSpin]

I agree with REDDOG, a wireway would clean this mess up. It also appears that the load side conductors from the two added disconnects appear to pass through the original disconnect. A disconnect isn't a pull box. NEC 312.8 prohibits it ("unless adequate space for this purpose is provided&quot. It's bad practice if not a clear violation. A wireway would fix this problem too.

 

[CHDean]

Not very pretty. You have a couple of issues. Based on the assumption that those are Square D H361 disconnects your first problem is with multiple conductors in the lugs. The switch is rated for one conductor per phase #14-6 copper.
Second issue is using the boxes as a wireway, clearly an NEC violation. The SqD switches have such small boxes that there is no room for the additional cable fill. If you have them correct it with square duct make sure they follow the wire fill guidelines on it.

 

[advidana]

This is why panelboards and MCC were invented- to prevent this type of installation. Why is first switch unfused. This kind installation fall under the tape rules in the NEC.

 

[TomFitz]

Thanks for all your responses,.. and yes I agree that it is a messy installation..
The setup for existing boilers have the MCC on the other side of the plant (not within view).. They brought one line from the MCC to the new boiler (rather than 3 lines) and have stated that according to NEC, the disconnets have to be close by within sight. They said the first switch is unfused because that main line is already fused at the MMC..

Tom..

 

[nfpa]

Dear Tom Fitz: I am looking for permission to use one of the photos that appeared in your article..Wiring through Service disconnects. We are the design firm working for the NFPA and their new magazine necdigest. the image is a panel board thread # 242-64412. WE will give photo credit. This is for the November 2003 issue.
PLease let me know
David wilson
Strategies Inc
wilson@strategiesmarketinginc.com

 

[amazingmg]

Ok, I know this is an old thread but I have a similar situation that I'm wondering about.

An existing 600A disconnect with parallel 350MCM per phase in 3-1/2" conduits that leaves the bottom of the disconnect and goes underground immediately. The disconnect is surrounded by other service equipment (multiple services) and there is not much room.

An ASCO automatic transfer switch was added to this feeder. The contractor mounted the switch nearby on a new concrete pad. To get from the disconnect to the ASCO switch and back the contractor installed 8" wireway and 3-1/2" conduits. That part looks fine. Inside the disconnect however you have parallel 350MCM leaving the load side of the disconnect going out the side of the disconnect through 2- 3-1/2" chases then you also have the same parallel 350MCM's coming back from the ASCO switch through 2 more 3-1/2" chases. Then splices were made to the underground feeder in the disconnect. So in the disconnect you have a big pile of splices and wire, but it is the same feeder, not a foreign one. The contractor used Burndy Unitaps which helped some if you've ever seen them.

Outage time was a concern, I think, since the service is for a call center type business.

Could this be a code violation?

 

[jrhaus]

amazingmg,

This is a code violation as enclosures cannot be used as a raceway. Enclosures are typically sized to accomadate wire in and out of the device. In addition, the splice within the enclosure is a potential for a fault, which could damage you service entrance disconnect, even though the Burndy Unitaps are a good product for connection of multiple connections. It appears to me that either a lager wire trough or a properly sized junction box should be used for the splice of the load side of the ATS conductors.

 

[resqcapt19]

jrhaus,

This is a code violation as enclosures cannot be used as a raceway.

Please cite the code section. Thanks.
Don

 

[amazingmg]

All I see is a reference in 312.8 to conductors feeding OTHER switches or overcurrent devices. This is the SAME feeder in the disconnect. Shrug.

312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space.

 

[dpc]

The issue being addressed in 312.8 is that the disconnect enclosure would need to be large enough to accommodate the additional conductors and terminations per NEC wiring space requirements. I also suspect this installation may not be in accordance with the UL installation requirements for the disconnect switch enclosure, which would represent an NEC violation in and of itself.

See Article 404.3 (B).

 

[amazingmg]

Passed inpsection.

 

[dpc]

Proving that the AHJ has the only opinion that matters (regardless of whether it makes any sense or not).

As long as you feel OK with the installation and it passed inspection, I guess the case is closed.

 

[TomFitz]

Thanks guys for all your input..
Personally I was not satisfied with it, but I passed on the info to the PE who runs the job and he was satisfied with it, the owner (the Army) was satisfied with it, and the people who run the plant were satisfied with it so.. (Shrug)... as long as I have my comments on record (in RMS, if it comes back to bite anyone later, it won't be me!
Being I'm an old Navy man working for the Army, I make waves from time to time. (but don't capsize the boat)..

Thanks again.....

Tom

 

[amazingmg]

Proving that the AHJ has the only opinion that matters (regardless of whether it makes any sense or not).

Agreed. There’s many a slip ’twixt the cup and the lip.


As long as you feel OK with the installation and it passed inspection, I guess the case is closed. [/quote]

Being primarily a contractor.......that sounds good to me.

Btw, TomFitz, didn't mean to be rude by interjecting on your thread here. I thought it was dead and since it was on a very similar subject....

 

[amazingmg]

BTW, I don't think there is a code violation on space as mentioned. You would have to go over the 75% fill mentioned in 312.8

 

[skiier]

This is an old post.
Cheesy wiring indeed.
Real amateur work. Was the Inspector blindfolded when he came by?
Code violations aside. How does one easily modify or remove any one disconnect?
A D box and some 1/2" sealtite flex would have been much easier. Probably faster install as well.
Oh well everyone is an Apprentice at one time.