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" ?