Ex accessories
Ex accessories
(OP)
With a Zone 2 motor where we have several accessories, for example Exe stator and Exe bearing RTD's wired to a EExe II auxiliary terminal box as standard, would it be possible to have the RTd's wired to a Exd auxiliary box





RE: Ex accessories
I am not familiarized with European Standard for Safety [CENELEC EN 60079-7 standard].
But from Engineering Guide I understand that EX"E" is lower protection as ex"d". According to NEC art 501 :
RTD is considered to be Simple Apparatus [close to Intrisincally Safe Apparatus]:
Simple apparatus is defined as “a device that will neither generate nor store more than 1.5 V, 0.1 A or 25 mW.”
Examples include switches, thermocouples, LEDs, connectors and RTDs. Simple apparatus themselves do not have to be approved, but must be used with an approved barrier and installed in accordance with the control drawing.
But as the auxiliary box is Ex"d" that means is located in a more hazardous area so the conduit should be provided with Ex"d" connectors on this location and sealing unilets filled with suitable material shall be provide to create a suitable barrier.
Best Regards