Motors and VFD's in hazardous areas
Motors and VFD's in hazardous areas
(OP)
All,
This is my first post to one of these sites. I have been trying to solidify my opinion on VFD's in hazardous areas and how our company should proceed. If I am in the wrong area for this type of post please direct me to the correct forum.
The question is what motor design factors are most important when specifying a motor for use with a VFD when ATEX approvals are requested by the customer?
Please assume the following:
1. The motor is Exd rated.
2. The motor is being used in the 10-100% speed range.
3. The motor is inverter duty rated.
4. The VFD is provided by one of the largest and most reputable VFD manufacturers.
Also can inverter duty ratings be applied by derating the DOL ratings by a specified amount.
Are there any other pitfalls in regard to ambient temperature?
I use a spring applied electrically released brake with every motor. I have run into availability barriers with brakes for high ambient temperature environments.
This is my first post to one of these sites. I have been trying to solidify my opinion on VFD's in hazardous areas and how our company should proceed. If I am in the wrong area for this type of post please direct me to the correct forum.
The question is what motor design factors are most important when specifying a motor for use with a VFD when ATEX approvals are requested by the customer?
Please assume the following:
1. The motor is Exd rated.
2. The motor is being used in the 10-100% speed range.
3. The motor is inverter duty rated.
4. The VFD is provided by one of the largest and most reputable VFD manufacturers.
Also can inverter duty ratings be applied by derating the DOL ratings by a specified amount.
Are there any other pitfalls in regard to ambient temperature?
I use a spring applied electrically released brake with every motor. I have run into availability barriers with brakes for high ambient temperature environments.





RE: Motors and VFD's in hazardous areas
I believe some here will disagree that VFD motor should ever be Exd rated others will not agree with that sentiment.
There was a lengthy thread on the subject a while ago - dang'd if I can find it though.
Any Exd motor would likely be TEFC. The fan would be severely ineffective in those sub 50-70% ranges. If you were also demanding rated torque at those speeds you would need to pile on some sort of auxiliary blower/cooling.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Motors and VFD's in hazardous areas
This may be the thread you are referring to.
thread237-95234: The Use of Explosion Proofs Motors on Distortion Supplies
humbled,
Hope the thread above is of some help.
RE: Motors and VFD's in hazardous areas
Please tell us where you are and what rules you have to operate under
RE: Motors and VFD's in hazardous areas
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Motors and VFD's in hazardous areas
Glad to help.