switchboard with class 2 wiring in it

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russ

Senior Member
Location
Burbank IL
On a inspection at a new business being built, the switchboard supprised me.

It is a custom unit, six mains, six seperate breaker bus set ups.
The suprising part was there is four low voltage thermostats,
and relays, and a bunch of class two wire in the wire way with the line voltage wire.


edit to change to switchboard, I first described it as switch gear
 

sandsnow

Senior Member
Rejecting might be a rush to judgement

Since it's a switchboard, it's probably listed by UL. The proper step would be to send a field report to UL asking if this board is in compliance and is eligible to bear the listing mark.

You can do this on the UL website. www.ul.com
Go to regulators. You will find a form you can submit online or fax. You can also submit digital pictures (Highly Recommended!!!!)

All the above assuming the board came that way from the manufacturer.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
But remember, just because something is UL Listed, does not mean it can always be installed per the NEC.
 

russ

Senior Member
Location
Burbank IL
It is UL listed (supposedly) under UL891.
I'll be back later with more info. Going there now to take some pictures.
 

russ

Senior Member
Location
Burbank IL
As far as the overcurrent devices, this panel meets the definition of a switchboard, so that part is ok.

As for the low voltage, so far UL has said as long as the low voltage devices and wiring were done by the manufacturer, that portion of the lowvoltage is legal.

Any low voltage wiring brought to the switchboard by the electrical contractor would have to comply with 725 (725.55).

I'm still not 100% sure I should approve this, I have a few more things to check out.
 

russ

Senior Member
Location
Burbank IL
PS The last picture is the low voltage thermostat wire hanging in the ceiling waiting to be put in the panel, and will tie in to the T/stats
 

sandsnow

Senior Member
This looks like it should be listed as an Enclosed Industrial Control Panel.
But, hey, What's in a name??

Anyway, I've seen a lot of products where field wiring has to be brought into the enclosure and it is Class 2. In a properly manufacured product, there is always an area or space that has a barrier between the high voltage and the low voltage for field wiring.

I can't really tell in the pictures here if that is the case.

I'm pretty sure this is what the UL standard calls for the manufacturer to provide.

I would also think that UL would require some sort of installation instructions addressing the field wiring.
 

dlhoule

Senior Member
Location
Michigan
What I want to know is did they give you doughnuts with that Dunkin Donuts coffee? If they did, what's the problem? :twisted:
 

russ

Senior Member
Location
Burbank IL
Well I've decided to approve this switchboard as long as they fix the problem you can see around the cover to low volt control devices. I'm not calling them T/STATS anymore since they aren't sensing the tempeture them selfs.
If you can't tell, there is a big space inside the access cover were you could reach in, or drop something on the bus below them.
Plus any field wiring brought into the board will be required to comply with 725.




 
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