Regarding explosion protection, for Ex nA II motors, the risk of arcing and sparking or hot surfaces during normal operation is prevented with an appropriate motor design therefore guaranteeing the required degree of safety. Motors with type of protection "non sparking nA" are used in explosive atmospheres, whereby, this atmosphere may occur in a potentially hazardous quantity. These motors are assigned to equipment group II - Category 3G (this corresponds to Zone 2). Loher Ex nA II motors are certified and optimally adapted for use in hazardous Zone 2 according to EN 50014 and EN 50021 or EN 60079-0 and EN 60079-15. They are stamped with II 3 G Ex nA II according to EC Directive (94/9/EC). The EC Declaration of Conformity documents that these regulations have been complied with.
What is worth noting: According to EN 60079-15:2005, a risk assessment must be made for all motors with rated voltages above 1 kV. Loher has successfully completed the type test for the stator and rotor according to EN 60079-15:2005. As a consequence, normally no additional measures are required up to 11 kV. With Loher motors, the complex purging process before the motor is started can be eliminated. When required, Ex nA motors also fulfill regulations relating to dust explosion protection according to EN 50281-1-1 // EN 50281-1-2. They are then additionally designated and documented with an EC type test certificate if the motors are operated in an environment with conductive dust. For variable-speed drives (converter operation), a type test must be performed with the actual converter intended for the application.