General

Hi,

I think it is important to remember that Ex maintenance courses teach you that you can change bearings that are on the outside of the flame path yourself, but that you must go to an authorised ATEX service facility to replace bearings that are on the inside of the flame path. Is this true? Have there been any changes in recent years? Is there a course for electricians and mechanics that covers being able to replace bearings on all Ex d motors?

This question was originally asked in Norwegian on the trainor.no Forum and has been translated.

Watches come in a wide range, from those costing almost nothing from Ebay, to luxurious designs worth six-figure digits. Basic wrist watches have not been a theme in Ex areas. Although most watches do not have any evidence that they can be used in Ex areas.

So-called smartwatches/sport watches have appeared on the market in more recent years. They have a wide variety of functions and designs. Most are waterproof to tens of metres and often charge wirelessly. These are also not supplied with any documentation to say they can be used in Ex areas.

Often, there is no full explanation as to why a regular watch can be used, but not a smartwatch.

I have a solid electrical background and have worked quite a lot with regulations/standards, but do not have an explanation for this whenever I have been asked. I clearly see the paradox, but have chosen to explain that Smartwatches etc. have no Ex documentation, and a line has to be drawn somewhere. Do you have anything more exhaustive?

This question was originally asked in Norwegian on the trainor.no Forum and has been translated.

When using Ex e equipment, calculations have been made of how high a surface temperature can be attained at a maximum throughput in the equipment. Normally Exe equipment is delivered with a max. ambient temperature of 40 degrees.

Based on what we have found in the documentation, a new ambient temperature must be stated on the Ex e equipment if the ambient temperature exceeds 40 degrees.

Our systems are in zone 2, Gas group IIB, and we have an analysis cabinet that has up to 60 degrees with Ex e equipment. Does this mean that all EX e equipment in the cabinet must have a new (Ta) ambient temperature applied?

Does this mean that we can only use equipment with temperature class T4,T5,T6?

We will confirm that an EX e connection box marked with (Ta) of 50 degrees cannot be used at a higher temperature.

This question was originally asked in Norwegian on the trainor.no Forum and has been translated.

Petroleum Safety Authority Norway’s facilities regulations, section 10a, concerning ignition source control is answered by the PSA as follows:

"Equipment and safety systems in classified areas must meet the requirements for use in explosion-risk areas, ref Norsok"

S-001 Chapter 14.4.2 Equipment in hazardous areas: Must comply with ATEX (Directive 94/9/EC).

"Equipment and safety systems that will be in operation during abnormal situations where an explosive atmosphere may occur outside classified areas must meet the requirements for zone 2 as a minimum." Ref Norsok S-001 Chapter 14.4.3 Equipment in non-hazardous natural coated areas must as a minimum be suitable for operation in Zone 2, including equipment in HVAC supply system.

ATEX states that Zone 2 equipment must be built to function safely in a normal situation. Does this mean that the equipment must be shut down in the event of an abnormal situation?

1. Are there different requirements for Zone 2 equipment if it is in an unclassified area where there is gas compared to in a classified area with gas?

2. Is there no requirement for ignition source shut-off of zone 2 equipment in case of gas? For example, type: A zone 2 truck used in zone 2. Shouldn't it be switched off in case of gas and all zone 2 equipment isolated?

My idea is that Zone 2 equipment has requirements for surface temperature to prevent ignition before the equipment is switched off. An EExe motor that can be in operation in gas in the area, for example, has a larger air gap between rotor and stator than an ExN motor that only has requirements for surface temperature, anti-static fan and ignition-proof terminals.

This question was originally asked in Norwegian on the trainor.no Forum and has been translated.