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NEC ratings for a simple device?

T

thomas

Jan 1, 1970
0
A customer wants to use one of our thermocouples in a Class II Div 1
environment (i.e. it must be dust-ignition proof).

From what I can tell by reading NEC Articles 500 and 502 (several times!) a
thermocouple is a "simple apparatus" and therefore does not need to be
marked with its evalutated Class, Division, etc. per 500.8 B(6)(d) "Special
Allowances for Simple Apparatus".

Our thermocouple assembly consists of a stainless sheath, potting compound,
thermocouple wire, bolted to a NEMA 3R Aluminum junction box. Being a
"simple apparatus" it looks like we won't need a more expensive Class II Div
1 rated junction box. And, it appears that UL Listing is not needed.

Does this sound correct so far?

If so, can we just label it with: "Rating: Class II, Division 1, Groups E,
F, G"?
Can we use the word approved: "Rating: Approved for Class II, Division 1,
Groups E, F, G" ?
 
C

Charles

Jan 1, 1970
0
thomas said:
A customer wants to use one of our thermocouples in a Class II Div 1
environment (i.e. it must be dust-ignition proof).

From what I can tell by reading NEC Articles 500 and 502 (several times!)
a thermocouple is a "simple apparatus" and therefore does not need to be
marked with its evalutated Class, Division, etc. per 500.8 B(6)(d)
"Special Allowances for Simple Apparatus".

Our thermocouple assembly consists of a stainless sheath, potting
compound, thermocouple wire, bolted to a NEMA 3R Aluminum junction box.
Being a "simple apparatus" it looks like we won't need a more expensive
Class II Div 1 rated junction box. And, it appears that UL Listing is not
needed.

Does this sound correct so far?

If so, can we just label it with: "Rating: Class II, Division 1, Groups E,
F, G"?
Can we use the word approved: "Rating: Approved for Class II, Division 1,
Groups E, F, G" ?

Don't really know, but I'd guess it is a low-voltage device and will not
require the Class II box or UL listing.
 
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