Certifications: Class I, II; Div 2; Groups

[dasarmin]

I have a production area that?s Class II, Division II, Group F (Dusts, Contained or not present in normal operation, Carbon Dust).
The Operator?s Interface is via a PC/TS (Xycom 15? PC / Touchscreen) mounted into a NEMA 9 enclosure (Rated for Class II, Div I, Group E, F or G).
Also, in this enclosure are a power supply, duplex outlet, CBs, etc; which are not Class II, Div II, Group F; but since these are inside the enclosure these don?t have to be certified Class II, Div II, Group F.
The PC/TS manufacture has discontinued my current PC/TS and their replacement is only certified for Class I, Div II, Groups A, B, C, D.

The question is, can the new PC/TS be installed into NEMA 9 and still meet code requirements for the room? The only exposure to the room is the bezel / Touchscreen, all the electronics (chassis) is essentially inside the NEMA 9 enclosure. The bezel?s gasket / seal is certified Class I, Div II, Groups A, B, C, D which is rated for Gases and Vapors. So you might think this would also keep out Dust

 

[G._S._Ohm]

The bezel’s gasket / seal is certified Class I, Div II, Groups A, B, C, D which is rated for Gases and Vapors. So you might think this would also keep out Dust

Dust and smoke are particles suspended in a gas, usually air.
Gases are atoms and molecules, vapor is liquid droplets suspended in air.
Atoms and molecules are smaller than the others.

If it keeps out gases I can't see how it can let in dust, but I don't do this type of testing for a living.

 

[jim dungar]

A device rated for Class I is not automatically rated for Class II.
Many times hazardous location ratings are not just about preventing ingress of 'hazards'.
For example: enclosures for dusty environments must be able to maintain a maximum surface temperature even when 'coated' in dust.

 

[weressl]

A device rated for Class I is not automatically rated for Class II.
Many times hazardous location ratings are not just about preventing ingress of 'hazards'.
For example: enclosures for dusty environments must be able to maintain a maximum surface temperature even when 'coated' in dust.

Correct.

In this particular case the Division 2 classification indicates that dust accumulation is not a concern. The ingress in Class II areas are prevented by the equipment simply being dust-tight, and if it can be determined that due to the previous temperature rating the equipment surface temperature does not exceed the AIT, there may not be an issue with external surface temperature either. Ingress can also be prevented by simple purging and the XP enclosure may not even be necessary.

 

[BJKorman]

Class 1 Div 1 Operator Interface

Class 1 Div 1 Operator Interface


I need a Class 1 Division 1 operator interface panel to basicallyturn on and off 50 pumps and look attank level. The panels Views from AB donot carry this even if purged. I can usea key pad and a screen, but do not want to use a mouse. Has anyone overcome this?

 

[jdsmith]

I need a Class 1 Division 1 operator interface panel to basicallyturn on and off 50 pumps and look attank level. The panels Views from AB donot carry this even if purged. I can usea key pad and a screen, but do not want to use a mouse. Has anyone overcome this?

Do you need a true touch panel or can the panel be for viewing only and can you use buttons wired to PLC digital inputs to do the control? If the panel can be used for viewing only you can put a fixed window kit over the panel and purge the front of the panel as well as the rear.

Sometimes the best design option is moving the panel out of the Div 1 area, or doing something to change the area from Div 1 to Div 2.