Hazardous Areas/Compex

Hazardous Area Basics - Hexagon Technology

if you have just come out of your 'time', may I suggest that you ask for a additional course for explosive areas, Ex rated equipment, UEL & LEL and zone classifications.

There are such courses which will remove all the guess work out of your question. However this COMPEX course you mention, will they not be covering Ex equipment etc as I have listed.

I understand your thirst for knowledge, and your slight confusion as to what, where and when..... I know, it can be really confusing. Ask for a training course, look for one that will certify you too! (in Ex equipment, not certify you insane).

I feel I have to say that while your question is far from mundane, the answer you will most likely get will be to direct you to finding said answer, rather than a full and complete one, as to cover all you ask would take a considerable amount of time and space, whereas a training course (I did two weeks with Shell UK) over a week or two, will cover ALL that you need to know.

Maybe so, however the gland is not needed for the purposes of explosion prevention; the EEx ia arrangements ensures that - one could in theory use bare conductors in zone 0 with EEx ia circuit arrangements in place. The IP rating of the gland is solely to avoid fluids getting into the enclosure and causing distress, and that's why there is no requirement on the cable glands under EEx ia.

IP rating is in respect of the actual environment the box and glands are mounted into, so you have to evaluate that and make a decision.

Ask the questions: is it exposed to rain, snow ice or other water- based threat eg flooding/ submersion ?

is it exposed to dust / particle threat ?

is it exposed to a corrosive gas/ vapour? (selection of materials)

Then Google 'IP ratings', and choose the best suited to your application. True, there is no such thing as cheap certified boxes or glands. However, the polycarbonate products are very versatile and reasonable enough in price.....I would still use Ex e glands myself, but only as a force of habit, and I'm not paying from my pocket...

Not sure where you are but in the USA we have NEMA ratings on enclosures that dictate what sort of EX environment and what atmospheric conditions an enclosure is allowed to be exposed to.

If you do not want to fork out the cash for standards another option is to subscribe to an on-line technical service that provides access to the various codes.

Designing EX type circuitry and installations carries a high level of responsibility because a failure usually results in massive equipment damage and/or human fatalities.

Although an Instrinsic EXP device might not present a source of ignition; failure of the device from chemicals, dust, water, or other contaminant could easily render a critical safety protective device or process step inoperable.

Whatever company you are working for should understand these liabilities and be more than willing to make sure you have access to and understand all aspects of the EX code before allowing you to design and/or install any EX equipment or circuitry.

At the very least a competent PE should be reviewing your designs, approving or rejecting them and giving you feedback.