Revisiting Class II Division 2 Enclosures

[gerbonic]

I have looked at the following threads and would like to seek additional opinions from the forum:

http://forums.mikeholt.com/showthread.php?t=143177

http://forums.mikeholt.com/showthread.php?t=159730

http://forums.mikeholt.com/showthread.php?t=115001

1. I have understood from these posts that Nema 4/4x is not not dust-tight and cannot be used for dust tight protection. Can someone confirm this?

2. If I have a dustight enclosure (lets say nema 3sx), does this mean that I can install general purpose devices in the box as long as it is dust-tight. The devices would be PLC, relays, IO boards, small breakers, etc? If find the answer to the breakers in 502.115(B), but what about the other general purpose equipment?

 

[rbalex]

One of our members is a NEMA Field Representative. He has noted recently that NEMA will be proposing changes to the NEC that will directly recognize the various NEMA 4 enclosures as dusttight.

 

[bphgravity]

Sorry to jump in on this so late.

See Public Input #1326.


Happy Holidays...

 

[bphgravity]

So, CMP 14 has created a first revision to add the following as an Informational Note to the definition to A100 "Dusttight".

"The term dusttight is typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 4, 4X, 5, 6, 6P, 12, 12K, and 13."


You should also expect ALL the definitions in Section 500.2 to be relocated to A100 in the 2017 NEC.


PI 1326 will be heard next week when CMP 1 meets. I will keep you all updated...

(If any of you are in Hilton Head - I am tracking CMP 14 & 16 this week. I will be tracking CMP 3, 8, 15 and maybe 12 or 19 next week)

 

[MasterTheNEC]

So, CMP 14 has created a first revision to add the following as an Informational Note to the definition to A100 "Dusttight".

"The term dusttight is typically used in conjunction with Enclosure Types 3, 3S, 3SX, 3X, 4, 4X, 5, 6, 6P, 12, 12K, and 13."


You should also expect ALL the definitions in Section 500.2 to be relocated to A100 in the 2017 NEC.


PI 1326 will be heard next week when CMP 1 meets. I will keep you all updated...

(If any of you are in Hilton Head - I am tracking CMP 14 & 16 this week. I will be tracking CMP 3, 8, 15 and maybe 12 or 19 next week)

GREAT JOB NEMA REP....!