Class 1 Division 1 & 2 General Question 1

[lbb7]

I have a bunch of questions when dealing with Class 1 Div. 1 & 2 Hazardous areas. I've looked through the NEC Articles 500 to 510 and the NFPA 496 and I'm still left with some nagging questions. So I will give a little background on what my company does and then I'll just lay out the questions. Any suggestions or comments would be greatly appreciated.
The company I work for manufactures oil water separators and at times these separators are placed in hazardous areas and I want to make sure that I'm meeting all of the requirements. The separators are always equipped with a purged control panel and we use Gexol type wire that is armored/shielded and terminated with the corresponding Hawke cable glands instead of conduit and this is where my questions arise. So, here go's.

1. In a Class I Div I area am I required to use the potted cable glands everywhere (Hawke type 753). In other words I know I have to use them on my field instruments but do I have to use them on the purged control panel or can I get away with the standard industrial Hawke cable gland?

2. Same question as above except Class I Div 2. Can I use the standard industrial Hawke cable glands on the purged panel and on the field instruments?

3. In a Class I Div 2 purged panel can I have power in the panel before the panel has been purged if it is known that the area is non-hazardous? Check NFPA 4.2.4 I know this is talking about conduit seals, but isn't it the same idea with cable?

Those are some of the more nagging questions, I'll leave it at that for now, but I do have a lot more.

 

[juleselec]

I don't find the NEC standards to be overly detailed when it comes to haz area installations, so I'm giving you an IEC perspective which is hopefully helpful.

1. According to IEC 60079-0, you must use a certified gland for Ex p enclosures, but it doesn't matter what type, e.g. Ex e, Ex d, etc. The glands at the control panel should be sealed as well to maintain the over-pressure.

2. Yes, same as (1) above

3. You can do whatever you like in a non-hazardous area. BUT it would be bad form to certify the equipment suitable for Class I Div 2 if this is the operating philosophy. Someone could move it into a hazardous area and think it is safe based on the certification.

 

[lacajun]

If this is still relevant.......

You have to use potted cable glands or seals on panels and instruments for C1D1 and D2. You'll need them on the purged control panel to ensure you have sufficient flow and pressure to reduce the concentration of gases.

You can apply power before purging in a non-hazardous area but ensure it really is non-hazardous. I know some that have been killed thinking they were in a non-hazardous area.

 

[JLSeagull]

The NEC handbook helps too.