Electrical cables through knockouts in JB/ wet location question

royguard

Member
Location
austin tx
Occupation
construction consultant
Is it acceptable to have three NM cables routed through the same knockout in the JB?

And, the NM cables are routed under a porch deck. The deck has a roof covering. Would you consider this an exterior wet location, thus the cables need to be exterior rated?
 

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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I don't recall that the code restricts the number of Romex cables that can come into the box at a single point. There might be a limitation based on the listing of the box or the connector.

I've never understood why underneath a porch where there is no water seeping down from above would be considered a wet location any more than why it would be considered a wet location when it's just under the ceiling of the same porch.

However I think in this case there's a good chance that wind blown rain could get onto the porch deck and filter between the deck boards thus getting the Romex cables wet.
 

SSDriver

Senior Member
Location
California
Yep box fill is over capacity, too many conductors in each connector, and by the looks of it I see water stains on the wood above the box and what looks like water spots on the cover of the JB and water/mud on the NM cable it self.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
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I've never understood why underneath a porch where there is no water seeping down from above would be considered a wet location any more than why it would be considered a wet location when it's just under the ceiling of the same porch.
...
The prohibition in 334.12(B)(4), prohibits NM in both wet and damp locations. I would see this as a damp location,
 

Srv52761

Member
Location
lowa
ok, can nm be stubbed from an inside wall to a weatherproof fixture box surface mounted on the exterior of a garage wall, or do you have to transition to uf or thwn in a jb on the inside?
 
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