How often electrical equipment must be inspected in the Czech Republic

The intervals of periodic inspections of electrical equipment are set by Annex 4 of Government Regulation No. 190/2022 Coll. (in Czech), in force since 1 July 2022. The basic maximum interval is 5 years in office buildings, 3 years in production, schools, accommodation and medical facilities, and 2 years where, according to the fire safety design, more than 200 people may be present. Besides the type of building, however, intervals by type of area also apply, and the shortest of them is always used.

• The intervals are in Annex 4 of Government Regulation No. 190/2022 Coll., and they are maximum intervals, not binding ones.
• If more than one interval applies to the equipment, the shortest one applies. This is where most mistakes arise.
• A shorter interval from the manufacturer in the accompanying documentation takes precedence over the annex.
• Drawn-up preventive maintenance rules allow intervals of up to double. Without them it is not possible.
• Only an inspection technician with a valid certificate may carry out the inspection, and the certificate is valid for 5 years.

Table of intervals under Annex 4

The annex divides the intervals into two groups. The first is governed by the building and the area, the second concerns protection against the effects of atmospheric and static electricity, that is lightning protection systems and surge protection.

For lightning and surge protection there are two intervals. A system protecting critical systems is inspected once every 2 years, other buildings and equipment once every 4 years. In addition, there is an obligation to carry out a visual check on all of this equipment at least once a year to verify that the system is not visibly damaged.

According to the annex, critical systems include Class I reserved electrical equipment and buildings where a lightning strike or surge could cause large-scale damage. The annex, however, also mentions buildings with sensitive internal systems and office and commercial buildings, so classification as an office building with a five-year interval says nothing about the lightning protection system.

The rule companies get wrong most often

The supplementary information to the annex says, word for word, that if more than one inspection interval applies to electrical equipment, the shortest of them is used. It sounds obvious, but in practice the interval is usually determined once, by building type, and never recalculated.

A production hall is a building for production, so 3 years. As soon as it contains a paint shop or a washing bay, it is at the same time a wet area or one with a permanent presence of polluting substances, and there the interval is 1 year. The one year applies, and only to the affected part of the equipment, not to the whole building.

The second common mistake is the opposite. The company takes the shortest interval from the whole premises and inspects everything by it. That is not unlawful, it just means paying for inspections nobody requires.

Three things that change the interval from the table

Accompanying documentation with a shorter interval takes precedence. Under Section 7(2) of the regulation, where equipment has a shorter periodic inspection or check interval stated in its accompanying documentation, the interval from the documentation is followed. Annex 4 therefore sets a ceiling, not a date.

Preventive maintenance rules, by contrast, extend the interval. Operators who have drawn them up and ensure the minimisation of risks through regular checks and maintenance may set periodic inspection intervals of up to double in them. It is the only lawful way to extend the interval, and it presupposes demonstrable ongoing maintenance, not just the existence of a document.

Work on the equipment resets the interval. In Section 6(4) the regulation lists the changes after which an inspection must be carried out regardless of the running interval: a change in the parameters of overload and short-circuit protection, a change in protection against electric shock, and a change in the properties of protection against the effects of atmospheric and static electricity.

When exactly the interval ends

The annex deals with it in one sentence: a periodic inspection must be carried out in the year into which the end of the set interval from the time of the last inspection falls. A last inspection in March 2023 with a three-year interval therefore means the next one must be done during 2026, not by 31 March 2026.

This relaxation, however, does not apply to intervals not exceeding one year. For wet areas, mobile equipment and construction sites, the actual date counts, not the year.

For planning this has a practical consequence. Intervals longer than a year can be grouped into one site visit and dealt with months in advance. Intervals of up to one year cannot, and those are exactly the ones most often missed.

Who may carry out the inspection

Under Section 9 of the regulation, an inspection technician is a natural person who holds a certificate of professional competence under Section 11(3) of Act No. 250/2021 Coll. (in Czech). This certificate is valid for 5 years from the date of issue.

The company as a whole also needs an authorisation under Section 8 of the same Act, which is issued by the authorised organisation and is valid for 10 years. Both are publicly traceable, because the authorised organisation keeps a register of inspection technicians as well as a register of companies holding an authorisation.

Two different validity periods in one company are, in practice, a source of unpleasant surprises. The company's authorisation runs for ten years and nobody thinks about it, while the certificates of individual technicians are renewed every five years and on different dates.

What this means for planning

Knowing the numbers is not enough. A company that inspects for several customers needs to know three things about each unit: what interval it has, when the last inspection took place and which technician holds a qualification in the scope that unit requires.

In capacity and skills, qualifications are kept against the technician, so the filter when planning excludes those who do not have the scope for the given equipment. That eliminates the most expensive mistake, a site visit by a technician who in the end is not allowed to sign the inspection report.

The date of the last inspection belongs with the order, not in a separate spreadsheet. In orders and history, the inspection report stays with the equipment, together with a record of who issued it and when, so the next interval is calculated from a documented date.

When you do not need to deal with this

As long as you manage one building with one interval, a note in the calendar is enough and you need nothing better. The same goes for a company that does not carry out inspections and only has them done.

The turning point comes with dozens of units with different intervals at different customers. From then on the question is not which interval applies, but which of the units has an interval ending first. That you can no longer reliably read from your head or from a spreadsheet.

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