Class 2, Div 2 Receptacles

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Ridgid

Member
Location
Minnesota
As far as installing 120 volt 20 amp receptacles in a class 2 div 2 environment what is needed for the proper installation? Rated for the use and connection to the equipment grounding conductor? Explosion proof is not needed, but what about no live or arcing parts? The location is existing and already has regular receptacles installed. I appreciate any input, thanks!
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Most of the major hazardous location manufactures make Class II, Div 2 Receptacles . (NOTE: "Class 2" usually refers to an Article 725 application)

While explosionproof isn't necessary, it isn't generally economical to manufacture a receptacle that is only listed/labeled for Class II, Division 2 since the basic performance requirements are virtually the same as Class I. That said, some "twist-lock" type receptacles are suitable under Section 500.8(A)(3) where the make/break is accomplished entirely within the receptacle and good housekeeping practices are in place. (NOTE: Dust accumulation usually indicates a Division 1 condition)
 

Ridgid

Member
Location
Minnesota
Most of the major hazardous location manufactures make Class II, Div 2 Receptacles . (NOTE: "Class 2" usually refers to an Article 725 application)

While explosionproof isn't necessary, it isn't generally economical to manufacture a receptacle that is only listed/labeled for Class II, Division 2 since the basic performance requirements are virtually the same as Class I. That said, some "twist-lock" type receptacles are suitable under Section 500.8(A)(3) where the make/break is accomplished entirely within the receptacle and good housekeeping practices are in place. (NOTE: Dust accumulation usually indicates a Division 1 condition)

Where is the requirement for de-energized parts, Or arc free environment?
 

Ridgid

Member
Location
Minnesota
What is the code regarding no live or arcing parts? I see connection to the EGC and listed but nothing regarding live or arcing parts.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
I apologize for the delayed response. I had to do a bit of research. I failed to consider revisions (and their unintended consequences) in the 2014 NEC.

From the 2011 NEC:
502.145 Receptacles and Attachment Plugs.
(A) Class II, Division 1. In Class II, Division 1 locations,
receptacles and 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,
receptacles and 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.

From the 2014 NEC:
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, receptac1es shall
be part of the premises wiring.
(2) Attachment Plugs. Attachment plugs shall be of the
type that provides for connection to the equipment grounding
conductor of the flexible cord.
(B) Class II, Division 2.
(1) Receptacles. In Class II, Division 2 locations, receptacles
shall be part of the premises wiring.
(2) Attachment Plugs. Attachment plugs shall be of the
type that provides for connection to the equipment grounding
conductor of the flexible cord.

From the 2013 ROP:
________________________________________________________________
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 aAttachment 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

It is important to note that, as far as the Submitter (UL) is concerned identified is identically equal to listed or labeled. So presumably, "...the requirement for de-energized parts, or arc free environment", is part of the UL product standards. That being said, it would appear that you won't get a Class II, Division 2 receptacle/attachment plug combo that isn't also explosionproof by default.
 
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