Electrical cabinet in ATEX zone

Hi,

Can someone with experience help me with the ATEX directive.
We need to put the control cabinet in the zone 21 and it is certified for this zone.

Does the equipment inside the cabinet need to be ATEX rated?
On the front of the cabinet we would put the equipment EX rated but I am not sure what does the directive say for the equipment inside.
Maybe someone with experience in European ATEX directive may shed some light?

Also the cabinet would have frequency converter. This converter is not for EX zone 21 but I have been told that if it is inside certified cabinet it could be in hazardous location. Someone who could verify this?

All you need to do is put everything in a purged or bomb proof box. Purged boxes are pretty much a normal IP68 cabinet with a positive air pressure supplied by a purge controller. Bomb proof is just a big box made out of inch thick plate steel and a lot of gaskets.

All i/o should go through intrinsically safe barriers.
All connectors should be ATEX rated for the zone or higher.
All glands need to be ATEX rated for the zone or higher.

Then you get someone with ATEX certification to rate the box and give you the stickers to go on the front of the box. All connections will need certifying and a "competent" person needs to do the wiring.

dbozic,

Don't forget the installation requirements of the conduit and devices.
In the US, we go by the national electric code NEC 70, the 500 section if my memory is correct. In regards to the enclosure(s), I would also buy a door lip for the top of the enclosure to keep the dust out if this is a dust environment.
You will need sealoffs as well which is often forgotten about.

james

Hi Chris and James,

Thank you for your help.
I have been looking more into ATEX, found this cabinet i.e.
http://www.r-stahl.com/uploads/tx_c...156126f7229f09ab2838a/IOM/0/8264603300_en.pdf

This can have sparking equipment inside(motor control equipment etc).

I am now looking some sort of timer relay which would be possible to mount on the front panel of the cabinet.
We need to leave possibility of changing the motor running time, and putting the DIN-mount timer in this cabinet looks to me very user un-friendly as it has many bolts, looking like it is not so easy to open.

Any suggestions?

You can use an external EX Potentiometer in the door and connect it
the timer inside the panel. You must find a timer that accepts an external pot.

nonuke said:

You can use an external EX Potentiometer in the door and connect it
the timer inside the panel. You must find a timer that accepts an external pot.

Click to expand...

Thanks, interesting idea. I have never used external potentiometer in multifunction relays.
I know they have coarse(h-min-s time scale) and fine tuning.
Does it mean that the potentiometer is only acting as fine tuning knob?
Meaning that it uses timeframe of the coarse screw knob on the time relay.

EDIT:
Ignore this. As I have seen potentiometer time relay do not have time base selection.