Class 1 Division 1 pump
- Thread starter steve66
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- Illinois
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- retired electrician
See 500.8(B)(2).
Ok, that makes sense.
I was looking at 501.125(B)(2), which seems to have an additional requirement that a motor have sliding contacts or some other type of switching ....
I'm not quite following why a Division 1 motor without any sliding or switching contacts couldn't be used in a Division 2 area. But the sump pump will have a float anyway, so I assume it does have sliding or switching contacts.
I was looking at 501.125(B)(2), which seems to have an additional requirement that a motor have sliding contacts or some other type of switching ....
I'm not quite following why a Division 1 motor without any sliding or switching contacts couldn't be used in a Division 2 area. But the sump pump will have a float anyway, so I assume it does have sliding or switching contacts.
I believe that is intended to say - if sliding contacts....switching mechanisms are employed, then it must be Div 1, as opposed to if Div 1 then it must have those components. Basically if there is anything that could arc/spark then it needs to be Div 1, otherwise it could be one of other constructions in (1) or (3) of that section.
That would make a lot more sense.
After reading it again, I think I get what they are trying to say.
powerpete69
Senior Member
- Location
- Northeast, Ohio
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- Professional Electrical Engineer
My interpretation of NFPA 497 is this:
For Class I, It is my understanding that Division 1 will always handle division 2 situations. However, Division 2 may or may not handle Division 1 situations.
Per NFPA 497 5.1.1.1 - Class I, Division 1: Ignitable gases exist under "normal conditions".
Per NFPA 497 5.1.1.2 - Class I, Division 2: Ignitable gases will normally be confined within closed containers or closed systems.
So glad I don't have to deal with this much anymore. It's usually 5 guys arguing in a boardroom for hours and hours. If you have 5 engineers draw up the area classification drawings, you will see 5 completely different drawings. There is so much room for interpretation. Plus you have guys wanting to protect their engineering firm vs the guys who have to pay the super high premium to do so. Due to the high price of electrical classification in the field, the factories tend to want to "wing" it with super high ventilation and call it good.
Hence the reason you should always say, "My interpretation of the area classification is....."
You simply can't state it factually.
For Class I, It is my understanding that Division 1 will always handle division 2 situations. However, Division 2 may or may not handle Division 1 situations.
Per NFPA 497 5.1.1.1 - Class I, Division 1: Ignitable gases exist under "normal conditions".
Per NFPA 497 5.1.1.2 - Class I, Division 2: Ignitable gases will normally be confined within closed containers or closed systems.
So glad I don't have to deal with this much anymore. It's usually 5 guys arguing in a boardroom for hours and hours. If you have 5 engineers draw up the area classification drawings, you will see 5 completely different drawings. There is so much room for interpretation. Plus you have guys wanting to protect their engineering firm vs the guys who have to pay the super high premium to do so. Due to the high price of electrical classification in the field, the factories tend to want to "wing" it with super high ventilation and call it good.
Hence the reason you should always say, "My interpretation of the area classification is....."
You simply can't state it factually.
Any motor used in Class 1 Div 1 must be listed for the area of use. Any three phase motor can be used in Class 1 Div 2. A single phase 220 volt motor with a starting switch would require a motor rated Class 1 Div 1 and be suitable for the hazardous gas type. Any arcing device changes that area from Class 1 Div 2 to Div 1
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- Mission Viejo, CA
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- Professional Electrical Engineer
Not quite. Read the definition of identified; it does not necessarily mean listed or labeled. In fact, Section 501.125(A) lists several alternate constructions for motors in Division 1 that may or may not be listed. Really, really big motors are often one of the alternates and no NRTL has a standard other than NEMA MG-1 to certify it by. [NEMA MG-1 doesn’t require listing or labeling.]
Don’s original response was correct. See Section 500.8(B)(2).
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