T3B vs. T2B 1

[hassankh]

I wonder if we can generally say that a T3B motor is better than T2B because of higher surface temperature?
or in the contrary, can a higher surface temperature (like T3B) for a motor possibly have higher risk of causing explosion in the area than a lower surface temp. motor (T2B)? Please let me out of this confusion.
Regards
hassan

 

[ScottyUK]

If this is an ATEX motor then the higher the 'T' number the lower the maximum surface temperature during operation, with T1 being the highest temperature and T6 the lowest. A T3 motor will have a lower surface temperature than a T2 motor, and can generally be used in place of a T2 motor providing other requirements are met such as gas group.

 

[waross]

I wonder if we can generally say that a T2B motor is better than T2B because of lower surface temperature?
What is available in your area?
How do the prices compare between T3B and T2B motors?
The cooler running motor may be the most efficient motor, but not always.
If you can use a T2B then the cheapest motor may be the best, or the motor that is easily available may be the best.
If you need the temperature rating of a T3B motor, then, of course, the T3B is the best.
If either of two motors is suitable for a given application, there may be more important criterea than temperature rating to determine the "BEST" motor for your application.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[hassankh]

Thanks for the answers.
What I mean is if a T3B motor is more likely to cause an ignition in explosive space than a T2B motor because of a higher surface temperature?

 

[ScottyUK]

No, because by definition a T3 motor has a lower operating temperature than a T2 motor. The 'B' defines the gas group and is not part of the temperature rating.

 

[hassankh]

Thank you for your kind reply.
So does this mean that T2B is more likely to cause an explosion? Can the motor's operating temperature (if high) cause an ignition in the first place?
Regards

 

[ScottyUK]

The idea is that you choose the motor to suit whatever gases it is going to exposed to. A T2 motor shouldn't cause an explosion if it is correctly applied. If you install a T2 motor in an area where a T3, T4, T5, or T6 temperature class is required then it possibly will. What gases will it be exposed to?

 

[hassankh]

I guess some ammonia will be present. So I've got my answer and now I have vivid picture what is really meant by this temperature code. Thank you very much