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#93889 - 06/22/05 03:57 PM walk-in refers
ccdave Offline

Registered: 01/27/03
Posts: 61
Loc: culver city,calif. usa
Does any one refer me to the code(s) that require rated boxes inside a freezer, waterproof or otherwise--please

2014 / 2011 NEC & Related Books and Study Guides
#93890 - 06/22/05 04:18 PM Re: walk-in refers
Joe Tedesco Offline

Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA
300.7 Raceways Exposed to Different Temperatures
Joe Tedesco, NEC Consultant

#93891 - 06/22/05 05:13 PM Re: walk-in refers
Roger Offline

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Dave notice the wiring compartment of the fan unit(s) inside the cooler or freezer, they are not (atleast in my experience of wiring many) special in weather or damp proof construction.

All wiring inside the unit will (in theory) be the same and should be dry.

As Joe mentions, conduits leaving the unit will be Exposed to Different Temperatures, and will need to have a block or seal from one environment to the other.


#93892 - 06/22/05 05:19 PM Re: walk-in refers
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
Funny things happen when conduits aren't sealed. Condensation will accululate in fixtures and conduits. Althought the fixtures and conduits may be rain-tight, or vapor proof, unless you stuff some duct-seal in the conduit, it will act as a vapor path outside the fridge. That cold air will mix with the warm air outside, and then you get a micro-weather system inside the conduit.
Mark Heller
"Well - I oughta....." -Jackie Gleason

#93893 - 06/22/05 05:21 PM Re: walk-in refers
iwire Offline

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Roger you bring up a good point about the fan coil units construction.

Out of tradition, habit, etc. we always feed these tin boxes with weatherproof means even though I do not think it is actually required.

I also have wired a pre-fab walk-in that was all dry location equipment. The inspector did question it but let it drop.

Personally I will stick with the weather proof stuff 'cause it looks right'.


[This message has been edited by iwire (edited 06-22-2005).]
Bob Badger
Construction & Maintenance Electrician

#93894 - 06/22/05 05:27 PM Re: walk-in refers
renosteinke Offline
Cat Servant

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
Equipment must be suitable for it's location- and that, of course, isn't always clear.
Thinking back, it seems to me that every freezer/ walk-in that I've been in has shared a few construction details.
While the boxes near the fan were of the "usual" type, the light switch, when inside the unit, has been of the lever-operated weatherproof type. I think that this is am attempt to comply with NEMA standards for equipment that will operate even where there is external icing (Is that Nema-3S?)
Lights have always been enclosed- either incandescents inside "jelly jars" or fluorescent tubes inside plastic sleeves.
Wiring has always either been pipe or MC.

I can't say any of this is "required," but it does seem to be the practice. Where the freezer is used for food, the USDA and the Commerce Department (fish) have a slew of their own regulations as well. I am sure the NSF (National Sanitary Foundation) has a standard that applies.

#93895 - 06/22/05 07:37 PM Re: walk-in refers
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
If you have ever "cleaned" a walk-in reffer, you know the best way is with a hose... The main reason for R/T, or weather proof.

The Code says it doesn't have to be explosion proof, but the raceway sealed from the conditioned to un-conditioned area. I don't think MC will cut it.
Mark Heller
"Well - I oughta....." -Jackie Gleason

#93896 - 06/22/05 08:10 PM Re: walk-in refers
Jps1006 Offline

Registered: 01/22/04
Posts: 609
Loc: Northern IL
I believe the cover bulbs around here is a health dept. requirment to prevent a broken bulb trashing lots of $$$ worth of food. You know they would likely tell them to just rinse it real good.


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