Electrical maintenance, rules to do!

Virtually all electricians work with electrical maintenance, but do you professionals in the Electrical Industry really know about electrical maintenance? It is common to receive doubts about electrical maintenance and thinking about it we resort to the NBR 5410 standard, to show what the standard says about electrical maintenance, thus removing your main doubts on the subject.

There are several types of maintenance, which is corrective, preventive and predictive maintenance, but in this text we will deal with two types of maintenance that are mentioned in the standard, preventive maintenance and corrective maintenance!

We explain what corrective maintenance and preventive maintenance is, in addition to explaining when we should perform maintenance, who can do electrical maintenance, what we should check for maintenance and among other questions we answer.

Learn how to do electrical maintenance.

Maintenance types – Corrective maintenance

This type of maintenance is the best known, and that people usually relate when they hear about maintenance.

Corrective maintenance is a type of maintenance that is done when a failure occurs, for example, a simple cable that overheated, broke and caused a short circuit. In this case, the electrician needs to intervene in the installation, change this cable and any components that have been damaged.

Types of maintenance – Corrective maintenance.

Types of maintenance – Preventive maintenance.

Preventive maintenance is routine maintenance performed on the premises to prevent any problems from occurring. This type of maintenance does not depend on a defect occurring to be performed.

A good example of preventive maintenance is the retightening of electrical connections, which must be done from time to time. In this example, the retightening of connections did not start from an electrical failure, but if this retightening is not done, over time the connections may heat up and consequently cause an electrical failure.

It is common for people to ask how often preventive maintenance should be carried out on the electrical installation, and some risk saying that this maintenance should be done every 5, 10, 15 and even 20 years.

Types of maintenance – Preventive maintenance

Preventive maintenance – Frequency

Regarding electrical maintenance and maintenance periodicity, chapter 8 of the NBR 5410 standard deals only with maintenance, and item 8.1 talks about periodicity of maintenance.

In item 8.1 it says that “the maintenance periodicity must be adequate for each type of installation. For example, this periodicity should be less the greater the complexity of the installation (quantity and diversity of equipment), its importance for the activities carried out on the site and the severity of the external influences to which it is subject. ”

The standard does not make it clear what is the correct time to perform maintenance, that is, in this case, common sense must be taken into account and the useful life of the equipment must be analyzed.

Preventive maintenance on conductors

The standard also addresses what should be observed in case of preventive maintenance. Item 8.3.1 deals with conductors and says that in conductors, the state of their insulation and its connection elements, fixation and support must be inspected, to detect signs of excessive heating, cracks and dryness, also if the fixation, identification and cleaning are in good condition.

Preventive maintenance on frames and panels.

The NBR 5410 standard also addresses what needs to be analyzed in the frames and panels, dividing it between the structure of the frames and the components.

The norm says that in the structure of the frames, the structure of the frames and panels should be checked, observing their general state regarding fixation, mechanical integrity, painting, corrosion, locks and hinges. In addition, the general condition of the conductors and grounding strands must be checked .

Preventive maintenance on components

With regard to components, in the case of components with moving parts, such as contactors, relays, disconnect switches, circuit breakers, etc., the condition of the contacts and arc chambers, heating signals should be inspected, when the component permits , cleaning, fixing, adjustments and calibrations are details that we must be aware of. Whenever possible, the component must be activated a few times, so that its operating conditions are verified.

The standard also talks about the cases of components without moving parts, such as fuses, conductors, busbars, rails, channels, connectors, terminals, transformers, etc., as the general condition of the component must be inspected, checking for the existence signs of heating and dryness, as well as fixation, identification and cleaning.

We emphasize that in the case of flags it is necessary to check the integrity of the bases, fixation, internal and external cleaning.

Electrical maintenance – Who can do it?

Who can do electrical maintenance? Anyone or just electricians?

This topic about who can or cannot do electrical maintenance is very controversial, but to clarify this issue we will again consult the standard.

Who can do electrical maintenance?

Item 8.2 of the standard says that “checks and interventions in electrical installations must be performed only by warned or qualified persons, according to table 18.”

Let’s look at table 18 below, to see which people are warned and qualified people

Rules for doing electrical maintenance.

Persons warned and qualified to perform electrical maintenance.

Warned persons are persons sufficiently informed or supervised by qualified persons, in such a way as to enable them to avoid the dangers of electricity (maintenance and / or operation persons).

Qualified people, the standard says, are “people with technical knowledge or experience that allows them to avoid the dangers of electricity (engineers and technicians)”.

The great controversy of those who can do electrical maintenance is due to the use of the term “sufficiently informed”, which does not clearly suggest the requirement of a course in the areas, but that is the subject of another article.

Electrical maintenance with energized circuit

Another important point of maintenance that many people have doubts and also generates controversy is about maintenance with energized circuits, whether this type of maintenance can be done or not.

The standard states in item 8.3 that the checks should be carried out, whenever possible, with the installation de-energized. Enclosures, covers and other means designed to ensure protection against contacts with live parts can be removed for checking or maintenance purposes, but must be completed and promptly reinstated at the end of these procedures.

The standard recommends maintenance with the circuit de-energized.

We can clearly see that the standard does not prohibit maintenance on an energized circuit, but this should only be done in extremely specific cases, taking all necessary care.

Like NBR 5410, the NR 10 standard that deals only with electricity safety, it also does not prohibit maintenance on energized circuits, but it is worth consulting and following chapter 10.6 of NR 10, as it is where all the details are concerned. guarantee the safety of the electrician in cases where it is necessary to perform maintenance on energized circuit.

The following video is from the Mundo da Elétrica channel, which teaches step by step how to maintain an industrial machine

In any maintenance procedure, it is essential to use personal protective equipment (PPE), in addition to carrying out risk analysis and remember, safety must always be taken seriously in any maintenance activity!v