Connectors for use in Class II, Division 2, Group G

[mb123]

I am curious what type of connectors might be suitable to replace a Deutsch DT style connector for use in a Class II, Division 2 application. These would be used in a 24V application, connecting temperature/pressure/proximity sensors and switches etc. on an industrial machine through an array of flexible conduit and sealed junction boxes eventually back to a controller located in an appropriately rated enclosure. Would going with a DIN4365A connector utilizing a molded extra-hard usage rated cord (e.g. SOOW) be adequate/necessary?

 

[rbalex]

...Would going with a DIN4365A connector utilizing a molded extra-hard usage rated cord (e.g. SOOW) be adequate/necessary?

Assuming you cleared the first hurdle of justifying the need for flexibility in the first place, my current gut reaction is "no" based on Section 502.10(A)(2)(5) [2011] as cross referenced by 502.10(B)(2). \But that is primarily because I'm unfamiliar with DIN4365A connectors. I did do a bit of "googling" and didn't find any basis for the connectors being "listed dusttight fittings". [Note the Article 100 definition of Fitting.]

 

[mb123]

Assuming you cleared the first hurdle of justifying the need for flexibility in the first place, my current gut reaction is "no" based on Section 502.10(A)(2)(5) [2011] as cross referenced by 502.10(B)(2). \But that is primarily because I'm unfamiliar with DIN4365A connectors. I did do a bit of "googling" and didn't find any basis for the connectors being "listed dusttight fittings". [Note the Article 100 definition of Fitting.]

Thank you for the quick response, Bob.

The following link gives these specific DIN43650A connectors a NEMA 4/IP65 rating; is this not adequate for the dusttight rating?
http://www.canfieldconnector.com/pr...shx?guid=07934d42-6cb0-4628-b221-163bc8ecc6ea

In regards to dusttight ratings, the Deutsch DT connectors carry an IP67 rating (http://www.deutsch.net/en/browse-products/connectors/composite/dt-series.html), but I was instructed that these would be inadequate for the following reasons:
1. Individual wires are routed into the back of the DT connector (these would have to be broken out of the extra-hard usage cord prior to the connector).
2. No tool is required to break the connection.

Are these requirements both valid for C2D2? Could the following statement in 502.145(B) be clarified: "...shall be designed so that connection to the supply circuit cannot be made or broken while live parts are exposed"?

 

[rbalex]

I appreciate the cut-sheets, but I still don't have a "warm-fuzzy" impression especially since the DIN43650A sheet doesn't say the device is actually listed at all - you have to consult the factory. This is a fairly common marketing ploy. Caveat emptor.

Depending on the NEC edition, you may also want to consult the notes at the bottom of Table 110.20 [NEC 2008] or 110.28 [NEC 2011 and later]. There you will find NEMA 4 isn't normally characterized as dusttight and, if you use the latest edition, [Table 110.28] IP ratings aren't recognized substitutes for enclosure types. [In the mid-nineties, I told several CMPs that mixing and matching NEC-NEMA-UL and IEC-CENELEC-EN would bring nothing but confusion.]

With regard to Section 502.145(B), it means that the circuit interruption is accomplished before the enclosure parts are separated AND the remaining energized conductors are still safely enclosed after the enclosure parts are separated. It doesn't seem the DIN43650A would do that.

 

[mb123]

Not sure I am any closer to a solution, but I do appreciate your input, Bob. Excuse my ignorance, but is there then a difference in being NEMA/IP rated and NEMA/IP listed? I see that the specific connector in question is not CSA listed without requesting one specified as such from the factory, but I did not think this was the case in regards to the NEMA/IP rating.

However, in regards to the other points you brought up, these connectors do not appear to be sufficient regardless, as I am also doubtful that they would meet Section 502.145(B) nor do they carry one of the NEMA ratings apparently required to be dusttight.

Back to the original question then, how are others connecting to these type of sensors/switches in a C2D2 approved manner? If one was to replace braided harnesses on an industrial machine in order to bring it up to Class 2, Division 2 requirements, should this involve rigid conduit throughout, and what is being done to interface with sensors, switches, etc.?

Thank you again for your insight.

 

[mb123]

With regard to Section 502.145(B), it means that the circuit interruption is accomplished before the enclosure parts are separated AND the remaining energized conductors are still safely enclosed after the enclosure parts are separated. It doesn't seem the DIN43650A would do that.

It looks like Section 502.145(B) changed in the 2014 version of the NEC. The only stipulation on attachment plugs mentioned here is that they provide for connection to the equipment grounding conductor of the flexible cord. Does this mean that the previous requirement "connection to the supply circuit cannot be made or broken while live parts are exposed" is null, or has this moved elsewhere? Would you agree this seems less stringent?

 

[rbalex]

Sorry for the tardy response. A long weekend with the grandkids and being the primary caregiver for my wife takes precedence. I also needed to review change history.

The following is from the NEC Committee Report on Proposals [2013]:

________________________________________________________________
14-97 Log #2476 NEC-P14 Final Action: Accept in Principle
(502.145)
________________________________________________________________
Submitter: Donald W. Ankele, Underwriters Laboratories Inc.
Recommendation: Revise text to read as follows:
502.145 Receptacles and Attachment Plugs.
(A) Class II, Division 1. In Class II, Division 1 locations, premises wiring
receptacles and the utilization equipment attachment plugs shall be of the type
providing for connection to the equipment grounding conductor of the flexible
cord and shall be identified for Class II locations.
(B) Class II, Division 2. In Class II, Division 2 locations, premises wiring
receptacles and the utilization equipment attachment plugs shall be of the type
that provides for connection to the equipment grounding conductor of the
flexible cord and shall be designed so that connection to the supply circuit
cannot be made or broken while live parts are exposed.
Substantiation: Revise to make clear that the receptacle is part of the premises
wiring and that the attachment plug is part of the utilization equipment. There
have been several instances of confusion regarding these Code requirements
with respect to cord being supplied with a plug for connection to receptacle on
the utilization equipment. Such a construction present and arcing hazard and
the potential for exposed live parts within the classified location.
Panel Meeting Action: Accept in Principle
Revise text to read as follows:
502.145 Receptacles and Attachment Plugs. Receptacles and attachment
plugs shall be identified for the location.
(A) Class II, Division 1.
(1) Receptacles. In Class II, Division 1 locations, receptacles shall be part of
the premises wiring.
(2) Attachment Plugs. and a Attachment plugs shall be of the type providing
for connection to the equipment grounding conductor of the flexible cord and
shall be identified for Class II locations.
(B) Class II, Division 2.
(1) Receptacles. In Class II, Division 2 locations, receptacles shall be part of
the premises wiring.
(2) Attachment Plugs. and aAttachment plugs shall be of the type that
provides for connection to the equipment grounding conductor of the flexible
cord. and shall be designed so that connection to the supply circuit cannot be
made or broken while live parts are exposed.
Panel Statement: The revised wording meets the intent of the submitter and
provides more clarity.
Number Eligible to Vote: 15
Ballot Results: Affirmative: 15

This is a good example of needing to read all the changes to Section 502.145 - not just 502.145(B)(2) including the new "main text": "Receptacles and attachment plugs shall be identified for the location." [Found in the Panel Meeting Action]

Also read the Substantiation. Essentially, Section 502.145 just doesn't apply to "quick-connects."

 

[mb123]

Depending on the NEC edition, you may also want to consult the notes at the bottom of Table 110.20 [NEC 2008] or 110.28 [NEC 2011 and later]. There you will find NEMA 4 isn't normally characterized as dusttight...

I am now questioning the statement that NEMA 4 is not characterized as dusttight. Table 110.28 specifies that NEMA 4 is adequate for "Windblow dust" as well as "Falling dirt", "Circulating dust, lint, fibers, and flyings", and "Settling airborne dust, lint, fibers, and flyings". To me, this would specify that NEMA 4 would indeed fall into the dusttight category.

It seems the listings below Table 110.28 may be hierarchical, e.g. I would assume Enclosure Type 6P could be classified as driptight though not specified here as so, as it is listed as being both raintight and watertight. Would you disagree?

 

[rbalex]

I am now questioning the statement that NEMA 4 is not characterized as dusttight. Table 110.28 specifies that NEMA 4 is adequate for "Windblow dust" as well as "Falling dirt", "Circulating dust, lint, fibers, and flyings", and "Settling airborne dust, lint, fibers, and flyings". To me, this would specify that NEMA 4 would indeed fall into the dusttight category.

It seems the listings below Table 110.28 may be hierarchical, e.g. I would assume Enclosure Type 6P could be classified as driptight though not specified here as so, as it is listed as being both raintight and watertight. Would you disagree?

You may question the statement but it is derived directly from NEMA 250 and UL 50.

The truth is most, but not all, NEMA 4 enclosures usually will also have some form of NEMA 3 identification.

With respect to IP ratings, you wouldn't have much problem selling me on their NEMA equivalents, but I'm not your AHJ. You definitely won't sell FedOSHA. Don't know about Iowa,

 

[mb123]

Thank you, Bob; I appreciate the insight!

 

[bphgravity]

Hello,

Go here for NEMA Enclosure Types as derived from NEMA 250: http://www.nema.org/Products/Documents/nema-enclosure-types.pdf

(Type 9 Enclosures are suitable for use in Class II locations)

 

[don_resqcapt19]

...
(Type 9 Enclosures are suitable for use in Class II locations)

But not required in a Class II, Division 2 area.

 

[bphgravity]

I need to recall my last post. Type 9 enclosures are no longer recognized per NEMA 250-2008.

ANSI / ISA 12.12.01-2012 now identifies Type 3, 3S, 3SX, 3X, 4, 4X, 5, 6, 6P, 12, 12K, & 13 as DUSTTIGHT and suitable for use in unclassified areas, Class II, Division 2, Class III, Division 1 & 2, & & Zone 22 areas.

Several correlating proposals are being submitted by NEMA for the 2017 NEC to reflect this change. One proposal will delete "other than hazardous (classified) locations" in the second paragraph of Sec. 110.28. Type 4, 4X, 6, & 6P will be added to Information Note #1 to T110.28.


Its hard to keep up with Product Standard changes. They occur more often and with much less fanfare as compared to the NFPA / ICC code change cycles...

THANKS!

 

[mb123]

You may question the statement but it is derived directly from NEMA 250 and UL 50.

I do not have the latest version of NEMA 250 available, but the version I have (1997) shows that all testing requirements for Type 3 (Outdoor Dust, External Icing, Outdoor Corrosion Protection, Gasket) are met or exceeded by Type 4 (External Icing, Hosedown, Outdoor Corrosion Protection, Gasket). The only test missing is the Outdoor Dust test, but 5.7 (Hosedown Test) states that "a device that meets the requirements of this test also meets the requirements of the...Dust Tests (5.5)". Would this not mean that Type 4 (and some of the others) meet dusttight requirements by default?