Class 1 Div 2 Solenoid Valve Location

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rich1956

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I am designing a control panel that has 24 VDC solenoid valves. The panel is non-purged in a Class 1 Div 2 group D location and according to NEC 501.3(B)(3), I can use a non-rated solenoid in a general purpose enclosure provided the external temp of the solenoid is less than 80% of the ignition temp of the group D gas. Is this interpretation correct? Has anyone done this type of installation or am I doomed to using Class 1 Div 1 Explosion proof type solenoids running ridgid conduit to those wonderful sealoffs?

Thanks in advance

Rich M
 
Re: Class 1 Div 2 Solenoid Valve Location

Standard NEMA 1 solenoids are fine in Class 1 Division 2 areas. Even in Class 1 Division 1 areas using a solenoid listed for that location, seals would not be required by the NEC.
Don
 
Re: Class 1 Div 2 Solenoid Valve Location

Don, your comment that a solenoid for a 1-1-D area only needs to be listed for that classification, and does not need seals.
Would you please check out Section 501.5(A)(1).
My interpretatation is that a seal is requred for any conduit leaving a Solenoid enclosure listed for a 1-1-Dlocation.
Thanks, Bob Friebel
 
Re: Class 1 Div 2 Solenoid Valve Location

Bob,
Look at the rest of the section that you cited. For seals to be required you must have one of the conditions listed. 501.5(A)(1)(1) requires seals if "The enclosure contains apparatus, such as switches, circuit breakers, fuses, relays, or resistors, that may produce arcs, sparks, or high temperatures that are considered to be an ignition source in normal operation," The solenoid does not meet any of these conditons so therefore 501.5(A)(1)(1) does not require a seal.
501.5(A)(1)(2) says, "The entry is metric designator 53 (trade size 2) or larger and the enclosure contains terminals, splices, or taps."
I've never seen a solenoid coil with a 2" conduit entry, so this section also does not require the solenoid enclosure to have a seal. If the conduit entry was 2" or larger, then a seal would be required.
Don

[ April 07, 2004, 08:58 AM: Message edited by: don_resqcapt19 ]
 
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