Hazardous Area, Terminal Blocks & Field instruments 1

[TTheHammer]

Hi All,
I guess this will be abit long, I'm designing the controls for a regulating station for a Class I Div I location, and all of the inside instrumentation are exiting via a terminal block then going to the control building. my question is :

Can I connect also the field equipment (which is outside the Class I Div I area) to the same terminal block, then pull everything through one conduit to the control building?

Or you think that I should have a seperate conduit for field equipments?

Thanks Guys

 

[hacksaw]

it depends on the area class for the terminal blocks.

 

[TTheHammer]

Thanks Hacksaw, I guess the TB are in Class I Div II, (I mean outside the building.

 

[ilan7]

Do not see any problem with using one terminal strip. PLease note:
1. If you are using Intrinsically Safe equipment at the Zone 1 area, you must have separate cables, boxes and terminals for them.

2. You just have to seal ALL the CABLE entering the Classified area at one end to avoid any posible gas flow inside the cables into the Non-Hazardous areas.

 

[ICman]

I strongly suggest you find an engineer with experience in hazardous area applications to review your system. I was just involved with a similar case, and was somewhat surprised with the unfamiliarity most had regarding hazardous areas. Guess I've been too close to it .

You may or may not be able to use a terminal strip for various devices. For instance, you cannot combine AC- and DC-powered equipment on the same terminal strip. The terminals must be appropriate for the area, as well.

ilan7 is correct in his recommendation that you seal the conduit. Intrinsically-safe devices are treated differently than other systems (like those rated for the area, or the use of explosion-proof enclosures), and the whole system must be designed correctly.

This is important! You need to be sure your system is safe, and will not pose a hazard to the public or to company personnel. Have the installation at least reviewed by a professional.

 

[SEB54]

Maybe you could use pneumatic purge system without eletrical supply...son you don't have to treat current

bye