Requirements for testing under ATEX

[PeterCharles]

I am getting conflicting statements regarding electric motors connected to variable frequency units.

Electric motors for use in ATEX Zone 21 or 22 need to be tested and certified, this is known.

One motor supplier is stating that where the motor is driven from a variable frequency unit it is necessary for the motor AND variable frequency unit to be INDIVIDUALLY TESTED AS A UNIT. (and this will cost £1500!)

A second supplier states that provided he is advised that the motor will be driven from a variable frequency unit and given information to establish the correct motor, testing of the motor with the variable frequency units is not necessary (the motors already having been certified under the requirements of ATEX).

Does anyone have any comment on the above that would clarify?

Regards

 

[ozmosis]

I can only speak for Siemens(as I work for them) but they have tested all their ATEX certified motors and will advise specifically which ones are suitable or not for inverter use. Try this link:

http://www.ad.siemens.de/sd/motoren/html_76/explosionsgeschuetzt.htm

To answer your question, it would be up to the motor manufacturer to test and certify.
If you want to speak to someone in Siemens A&D UK you could speak with Malcolm Bailey/Phil Batley/Paul Bruce on 0161 446 5333 who seems to be the resident experts on the ATEX motors. I assume you are in the UK by the way.