Switchgear in AEx area 1

[Murlinor]

Friends,

I want to install a switchgear in a class 1 division 2 AEX area. Someone has suggested to use a SF6 insulated padmounted switchgear. The question is if the switchgear tank is intended for use in class 1 division 2 (group D) area, what then about the elbow cable connector to be to connected to the switchgear bushing? Shall I specify a elbow cable connector that has a class 1 division 2, group D classification as well?

Thanks in advance

 

[Bilegan]

Check and verify from the manufacturer if the SF6 insulated pad mounted switchgear you are planning to install in hazardous area is suitable for Class I, Division 2, Group D location.

Purging/pressurization method to safely operate switchgear in hazardous classified locations may not be commercially available. Better to look and explore possible location of SF6 pad mounted switchgear outside the hazardous classified area.


Regards,
Bilegan

Murphy's Law - If anything can go wrong..it will.

 

[Murlinor]

Thanks sir for your reply.

The manufacturer is offering a 38kV switchgear and saying that this switchgear can be used in class 1, div 2 area based on the following standard:

NEC 501.115(B)(1) it states:

(1) Type Required. Circuit breakers, motor controllers, and switches intended to interrupt current in the normal performance of the function for which they are installed shall be provided with enclosures identified for Class I, Division 1 locations in accordance with 501.105(A), unless general-purpose enclosures are provided and any of the following apply:

(1) The interruption of current occurs within a chamber hermetically sealed against the entrance of gases and vapors.

OSHA 1910.307 states:
1910.307(f)(9) Hermetically sealed. This protection technique is permitted for equipment in Class I, Division 2; Class II, Division 2; and Class III, Division 1 or 2 locations.

Is this allowed? Shouldn't there be a conformity declaration that says that the SWG is permitted in a class1, division 2 area?

 

[Bilegan]

NEC 110.3 Examination, Identification, Installation, and use of Equipment

(A) EXAMINATION. In judging equipment, considerations such as the following shall be evaluated:
(1) Suitability for installation and use in conformity with the provisions of NEC.
(2) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided.
(5) Heating effects under normal conditions likely to arise in service.
(6) Arcing effects.
(7) Classification by type, size, voltage, current capacity, and specific use.

(B)INSTALLATION and USE
In hazardous (classified) areas like your case Class I, Division 2, Group D, equipment that is required by the National Electrical Code (NEC) to be approved shall be labeled or listed or certified by Underwriters Laboratories, Inc. (UL).

Ask the manufacturer to provide you the UL certificate that the 38kV Pad Mounted Switchgear is suitable for hazardous area Class I, Division 2, Gas Group D location. If you can able to get it please kindly attached to your reply.

Regards,
Bilegan

Murphy's Law - If anything can go wrong..it will.

 

[Murlinor]

Thanks! That was really informative.