ATEX certification

[cloggs]

I have a ATEX certified Motor being situated in a Zone 1 Hazardous area.
I require an inverter to make the moter twin speed.
The invertor will be in a IP65 rated panel in safe area.

Does the inverter need to be ATEX approved.?
If the inverter is not ATEX approved will it void the motors certification.

Thanks in advance.

 

[stardelta]

Your inverter does not have to be ATEX approved. Only equipment released into the European market from the end of June has to have this approval and it only applies to equipment for use in hazardous areas. However its vital you check with the manufacturers/suppliers of the motor to clarify its suitability for use with an inverter in a hazardous area. The danger is from excessive surface temperature being generated when running below design speed due to the reduced effect of the cooling fan. This can take it above its rated T class. Most (but not all) Ex motors employ thermistors when running under inverter control to prevent overheating. Try this site.

http://www.siraservices.com/media/tech_info/atex137datasheet.html