Ex equipment repair: what are the user’s responsibilities?

When it comes to selecting pumps and their associated systems for use in hazardous areas, the requirements to make zoning assessments and, in turn, select the appropriate equipment are well understood. But, what about when it comes to repairing equipment in these environments? Karl Metcalfe, Technical Support Officer at the Association of Electrical and Mechanical Trades (AEMT), takes us through some of the considerations which need to be made.

End users maintaining their own Ex equipment or sending it away to a repairer should be aware of what the international standard BS EN IEC 60079-19:2019 states regarding their responsibilities. Here is an extract:

4.2 Instructions for the user

4.2.1 Ex Equipment Certificates and schedule drawings

The equipment user should be aware of any relevant legislation with respect to periodic inspection and verification to ensure that electrical equipment installed in explosive atmospheres is fit for purpose. The user should consider whether sufficient facilities and competencies are available to undertake the repair or overhaul of such equipment by the user or whether it should be contracted to specialist repair and overhaul service providers. In addition, the user should be aware that sufficient information has to be provided to third-party service facilities and installers to meet occupational health and safety obligations.

Not all items of Ex equipment have the same protection concepts, yet different concepts can be in the same Ex zoned area. Understanding these protection concepts will help site maintenance engineers maintain and inspect these motors without compromising the Ex protection.

For example, if corrosion is identified during periodic maintenance checks which involve removing a terminal box lid from an Ex rated machine, it may require a check of flamepath gaps. This would require knowledge of identifying flamepath lengths and maybe even a calculation of volume to ascertain what those gaps are in relation to the Ex atmosphere in which the equipment is placed.

If the Ex equipment is sent away to a repairer for overhaul service or repair, then, as stated in the standard extract above, it is the user that needs to consider whether the repairer has sufficient facilities and competencies to carry out the work required.

A dossier for the piece of equipment should be kept by the end-user and given to the repairer when service repair or overhaul is required. This dossier would then be returned to the end-user with all work carried out, and information on the repair added to it.

In addition, a repair label should be attached to the piece of equipment showing information including:

• The relevant symbol, to denote the type of repair.

• The standard/standards number to which it was repaired too.

• The name of the repairer or his registered trademark and service facility third-party accreditation, if any.

• The repairer’s reference number relating to the repair.

• The date of the overhaul or repair.

But how do you know that the service centre you use, and trust, is competent and has the systems in place to meet the requirements of the international repair standard?

Not using an authorised Ex repairer potentially puts the safety of an end-user’s onsite employees at risk, but also risks serious financial repercussions. If a problem occurs, an insurance assessor would want to see the repair records of the Ex equipment, if none exist, why would they pay the claim? Creating a paper trail of services and work carried out, and evidencing the fact that the equipment installed was fit for purpose, meeting the required standard, would solve this problem.

Throughout the repair industry, AEMT members have varying certification details of which are listed on our website. Members who have achieved IECEx certification use AEMT Ex courses to keep up their required refresher training every three years, these service centres are regularly independently audited by a notifying body and then certified as achieving this accreditation.

The AEMT also has an Ex register. To be registered members need to have undergone, and kept up to date, the same Ex training courses, and they must have systems in place so they can work with the requirements of the international repair standard. chevron-