class1 division2

[tekro]

Please kindly inform me is UL 1203 rule is the reference standard for Class 1 division 2. If so, I would like to know, if explosion proof enclosures "Cooper" manufacture type EJB need to be submitted to explosion tests when inside there are components such as contactor, relays or fuses.
I have to manufacture an enclosure, but I do not understand if explosion test required by UL 1203 must be performed or not, after enclosed inside the same the components to complete the plant.

 

[bobgorno]

Testing must be by a NRTL for it to matter. You can not run the test. If a Cooper-Crouse-Hinds enclosure is listed, it has already passed the test. You must use it per the manufacturer's instructions, including following their requirements for maximum number and sizes of drilled and tapped entry hubs.

Mounting of a contactor, relay, or fuses on the sub-panel inside of the enclosure is part of its intended use, so you should not be effecting the listing.

Make sure all of the bolts are in place and tight. Do not damage the machined flanged surface. Conduit seals must be installed properly.

Check out their web-site, they have some good reference info.

 

[petersonra]

There is a special UL listing for fabricated control panels for use in hazardous areas, somewhat like UL508a is used for industrial control panels. You have to be qualifed by UL and subject to their rules to be able to list panels this way.

I wonder how long it will be before local jurisdictions start enforcing this?

 

[tekro]

THANKS A LOT FOR YOUR PROMPT REPLY, BUT FOR CLASS 1 DIVISION 2, I HAVE INDIVIDUATED THE RULE UL 1203, WHICH INDICATES AS FOLLOWS:
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UL Standard for Safety for Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations, UL 1203 Fourth Edition, Dated September 15, 2006:

21.2 Equipment for use in Class I locations shall be subjected to a series of tests conducted in the presence of the specific gas- or vapor-air mixtures over the range of flammable or explosive concentration to determine:
a) The maximum explosion-pressure effects of the gas- or vapor-air mixtures over the test range specified in Table 21.3;
b) The maximum propagation effects of the gas- or vapor-air mixtures as specified in Table 21.3; and
c) That an electrical mechanism having contacts does not fail mechanically or electrically in the presence of explosive atmospheres when such tests are required. See 21.5 ? 21.7.
21.7 For Class I, Group C or D locations, equipment intended for connection to a circuit with a maximum available short-circuit current of 10,000 rms symmetrical amperes is to be subjected to spark plug ignition tests with the intended electrical mechanisms in place. In addition, such equipment for Class I, Group C locations rated over 125 volts is to be subjected to explosion tests to determine that electrical mechanisms having contacts does not fail electrically when operated at maximum rated voltage and a load of nominally 10 amperes or rated current at maximum rated voltage, whichever is lower. The load characteristics are to be the same as the load characteristics required for ordinary-location use when the equipment is subjected to an endurance test. The application of an equivalent load is capable of being used to comply with this requirement.
21.10 For Class I, Groups A, B, C, or D locations, equipment having an internal fuse shall be subjected to explosion tests using a spark plug to ignite the flammable mixture, and by overload and short-circuit tests to determine the electrical and pressure effects resulting from rupture of the fuse.

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WHAT I UNDERSTAND IS THAT, IF I EMPLOY UL1203 I MUST PERFORM THE EXPLOSION TEST BY NRTL. THEREFORE PLEASE CLARIFY IF EACH TIME I HAVE TO MANUFACTURE A PLANT IN CONFORMITY WITH UL1203
HAVE I TO PERFORM THE EXPLOSION TESTS? SO EACH TIME I MANUFACTURE A NEW PLANT SHALL I SUBMIT IT TO AN EXPLOSION DESTROING IT TO SATISFY THE TEST REQUIREMENTS AND THEN SHALL I MANUFACTURE A NEW ONE? I DEEM IT A VERY EXPENSIVE METHOD....OR DO I WRONGLY UNDESTAND THE RULE?
NOTE: I AM ABLE TO MANUFACTURE INDUSTRIAL CONTROL PANES IN CONFORMITY WITH UL508A.

 

[petersonra]

I believe UL will not allow you to list under UL508a if the panel is designated to go into a classified area. You have to list it under UL698 if you want to put it in a classified area. It is similar to UL508a in that you can build up panels from listed parts in accordance with a specific procedure.