Class II Div 2 Motor

[RTMintus]

For a Class II Div 2 (G) location, is a TEFC motor for pump or fan use with 40C ambient and class B or F wiring (SF 1.15) acceptable? The autoignition temperature is 300C.

502.8(B) would seem to indicate the enclosure was acceptable with a normal operating temp of 130C or 155C which is below the 165C limit in 500.8(C)(2).

 

[rbalex]

I have no idea what 502.8(B) is. You probably meant 500.8(B). In any case, Section 502.125(B) is where you should look.

 

[RTMintus]

I have no idea what 502.8(B) is. You probably meant 500.8(B). In any case, Section 502.125(B) is where you should look.

Sorry for the typo. I was looking at 502.125(B) , which allows for a TEFC motor, and calls out a max temp "in accordance with 500.8(D)(2) for normal operation when operating in free air".

 

[rbalex]

Then you pretty much answered your question. It may be worth reviewing the Exception although what you already proposed is acceptable. The Exception emphasizes that housekeeping is also valuable. This is especially true in Group G where the dusts are often nonconductive and nonabrasive.

 

[RTMintus]

Then you pretty much answered your question. It may be worth reviewing the Exception although what you already proposed is acceptable. The Exception emphasizes that housekeeping is also valuable. This is especially true in Group G where the dusts are often nonconductive and nonabrasive.

Looking at 500.8(D)(2) references temperature T-code markings in 500.8(C). However, the only motors with T-codes are ones listed for hazardous locations. But the T-codes on motors are maximum temperatures for normal or abnormal operation. This would imply the motor is listed for a hazardous location, correct?

 

[rbalex]

Compare Sections 502,125 (A) and (B). As a general rule, NEMA motors are neither required to be listed nor labeled. Motors for Division 1 are required to be identified for the application or to be specifically TEPV. Motors for Division 2 have no specific listing or labeling requirements. [NOTE: identified does not necessarily mean listed or labeled.]

Section 430.7, specifically Subsection 430.7(A)(5), requires a motor's nameplate to include relevant temperature markings. A temperature rating does not necessarily imply suitability for hazardous locations nor listing, although it probably is suitable but not listed,. See Section 500.8(A).