Electrical installations

An electrical installation is a set of protective equipment, wiring, switches, sockets, luminaires, etc., permanently installed in a building. Safety must be ensured during the use of the electrical installation and during electrical work carried out there.

An electrical installation may be put into service if:

  • the facility complies with the requirements and is in good technical condition;
  • the installation is provided with the necessary control, monitoring, and protection equipment, which is reliable and in good working order for the use intended;
  • where appropriate, an audit has been carried out, which shows that the installation is technically safe.

Both the owner and the holder of the electrical installation are responsible for its compliance.

When using electrical installations, it must be ensured that:

  • the necessary conditions are provided for the proper use and maintenance of the installation;
  • appropriate information is made available and accessible to persons coming into contact with the installation;
  • the use of the installation is stopped where an imminent danger becomes apparent;
  • the requirements for the service and maintenance (operation) of the installation are complied with;
  • where provided for, a person responsible for ensuring compliance with the requirements for the use of the installation, i.e., the person responsible for supervising use, has been appointed;
  • an audit has been carried out, where applicable.

Electrical installations are classified into three types according to their technical parameters and hazards:

  • The first category includes installations with a high level of risk, such as electrical installations in or containing an explosion hazard zone (e.g., petrol stations), a hazardous site in a major-accident establishment, and hospitals and medical premises where mains-powered electrical medical equipment may be used in the treatment rooms, parts of which are in physical contact with the patient during use.
  • The second category includes low-voltage electrical installations with the main protection of more than 35 amperes (commercial and office buildings, industrial buildings, etc.), electrical installations in accommodation buildings, electrical installations shared by tenants of buildings with more than two apartments, and all high-voltage electrical installations (e.g., substations).
  • The third category includes electrical installations with a rated main circuit protection current of 35 amperes or less, not electrical installations of either the first or the second category.

The operation of an electrical installation is an activity to maintain the installation in a satisfactory condition. It includes, in particular, switching, control, inspection, maintenance and both electrical and non-electrical work.

The operation and electrical work on electrical installations must be carried out following good practice, the requirements described in EVS-EN 50110-1.

An electrical installation operating plan is a document or set of documents that specify the procedures, processes, and operations required to keep, switch, control, inspect and maintain an electrical installation in operation. The operating plan must be in writing.

To ensure the safe operation of an electrical installation, the responsible person (owner or holder) must appoint a supervisor (a "movement supervisor") to ensure compliance with the requirements for the use of the electrical installation, if there is an electrical installation:

  • in an explosion hazard zone or a building containing an explosion hazard zone;
  • a hazardous installation of a major-accident establishment;
  • in a hospital or other healthcare establishment where mains-powered medical electrical equipment may be used in the treatment rooms and parts of which are in physical contact with the patient during use;
  • a treatment room, other than in a healthcare facility, where mains-powered electrical medical devices may be used, the components of which come into physical contact with the patient during use;
  • low-voltage switchgear and control gear with a rated mains protection current exceeding 100 amperes;
  • high-voltage equipment, irrespective of the nominal main fuse rating.

The competence of the person supervising the use must be certified. A person's competence is certified if he holds a relevant professional certificate or a certificate of competence.

The person's competence must be certified for the management, design, and audit of electrical and commissioning works. A person's competence is certified if he holds a professional certificate or a certificate of competence appropriate to the electrical work to be carried out and the electrical installation's technical specifications.

Competence to carry out the design and audit of electrical installations shall be attested from level 6 of the electrical profession or equivalent level by a competence certificate.


Qualification certificates are issued by professional bodies authorized by the Chamber of Vocational Qualifications. When awarding a professional qualification, the professional assesses the person's skills and knowledge in the relevant professional field following the professional standard. 

In the case of certificates of professional competence in the field of electricity, the level of the profession (levels 4 to 8) indicated on the certificate, together with the specialization (indoor work, distribution network, electrical automation, electrical networks and systems, consumer electrical installations, etc.) and the chosen work components (design, construction, installation, supervision, etc.) must be taken into account.

For more information on the vocations, please consult the website of the Chamber of Vocations www.kutsekoda.ee.

Competences and competence classes

Staff certification bodies issue certificates of competence. To obtain a certificate of competence, a written examination must be passed. The examination questionnaire shall be drawn up based on the legislation and the documents and literature relating to the equipment.

Certificates of competence are divided into Class A, B, B1, and C certificates of competence.

The class A certificate of competency entitles the holder to supervise electrical installations and operations and to carry out audits on electrical installations of any technical specification.

A class B certificate of competence entitles the holder to manage electrical installations and installations and to carry out audits on low-voltage electrical installations:

  • to supervise the construction of electrical installations in low-voltage electrical installations with a rated main circuit current not exceeding 63 A, except for design and technical inspection work;
  • being the person in charge of the operation of low-voltage electrical installations with a rated main circuit breaking capacity not exceeding 250 A.

A class C certificate of competency entitles the holder to supervise the repair of low-voltage electrical equipment, but not electrical installations.

The right to carry out design and audit work is conferred by the class of competence only if the person concerned has a degree in electrical engineering. By way of derogation, the personnel certification authority may grant the right to carry out design work and technical verification within the class of competence if the person demonstrates his/her ability and previous experience to carry out design work or audits.

Certificates of competence shall be valid for a period of five years. Please note that certificates of competence issued before 01.07.2015 are valid until the date stated thereon.

To renew (recertify) a certificate of competence, an abridged competence examination must be passed. Also, refresher training is required. The required number of hours of the refresher training is 24 academic hours. Only refresher training completed in the last three years of the recertification period will be taken into account.

Competences obtained abroad

If a person's competence has to be certified and the person has acquired the required level of competence abroad, the Act on the Recognition of Foreign Professional Qualifications applies to its recognition. In this case, the person must apply to the Consumer Protection and Technical Regulatory Authority to recognize their foreign professional qualification.

An undertaking carrying out electrical work as an economic activity must submit an economic activity declaration. The declaration of economic activities can be submitted electronically directly to the register of economic activities at https://mtr.mkm.ee. If the undertaking cannot submit the notification electronically, it must submit it to the Consumer Protection and Technical Regulatory Authority.  The undertaking must have a manager of proven competence.

After carrying out the electrical work, the person carrying out the electrical work must satisfy himself, based on the results of the measurements and tests, the visual inspection, and the documentation, that the electrical installation and the electrical work carried out there comply with the requirements. The work must be documented.

Commissioning and electrical work must be carried out by a person who has the necessary technical and safety knowledge and experience. The electrical safety awareness and experience of the person carrying out the commissioning and electrical work must be verified by the person in charge of the electrical work or by the supervisor supervising the use of the electrical installation or by a competent authority or person authorized by them. The electrical safety awareness check must be documented.

Temporarily, electrical work may also be carried out in Estonia as an economic activity by an undertaking lawfully carrying out electrical work in another Member State of the European Economic Area. In this case, the entrepreneur must comply with the safety requirements for electrical work when carrying out electrical work in Estonia but is not obliged to submit a notification of the economic activity.

Electrical work permitted for non-professionals:

  • Work with electrical equipment with a voltage rating of 50 V a.c. or less, or 120 V d.c. or less, supplied from a protective earth source;
  • work on electrical installations with a voltage rating not exceeding 50 V a.c. or 120 V d.c. provided from a protective earth voltage source;
  • maintenance work on electrical equipment with a rated voltage of 230 V or less, disconnected from the mains supply, not involving electrical circuits with a rated voltage of more than 50 V a.c. and 120 V d.c.;
  • the replacement of accessories, such as light sources, starters, and fuses, typically intended to be replaced by the user, with accessories of an approved designation, in a voltage rating of 230 V or less, in a voltage-free condition;
  • the switching on and off of automatic circuit breakers and protection circuit-breakers authorized for use by any person and the checking of the tripping of the residual current circuit-breaker through switching on and off;
  • checking the voltage utilizing an indicator on electrical equipment with a rated voltage rating up to 230 volts;
  • connection of luminaires without a protective conductor to the luminaire terminals in a de-energized condition;
  • Removal of unprotected sockets and switch covers in a de-energized state;
  • dismantling of electrical wiring and equipment in a de-energized state.

In the course of the audit, the auditor visually assesses the electrical installation condition, examines the installation documentation and test and measurement results, and, if necessary, carries out additional control measurements in the installation. Based on all this, the auditor decides whether the installation meets the requirements and is safe for use.

Only accredited inspection bodies may carry out audits on electrical installations.

The audit is divided into a pre-commissioning audit, a regular audit, and an exceptional audit.

The pre-commissioning audit shall be carried out before the electrical installation is put into service, i.e., after the new electrical installation has been completed or the old one has been rebuilt. The electrical installation shall not be put into service before the audit.

A pre-commissioning audit is not required:

  • for temporary low-voltage electrical installations of the third category 
  • for an in-service part of a proper low-voltage installation where the protective device's rated current upstream of the supply line does not exceed 35 amperes.

In this case, the installer of the electrical installation shall confirm in writing, based on the results of measurements and tests, visual inspection and documentation, the conformity of the electrical installation with the requirements, and the safety in use.

The ad hoc audit shall be carried out as necessary, and the contracting entity shall determine its scope and the normative documents to be used as a basis for the audit.

Periodic audits shall be carried out periodically on electrical installations in service, depending on the installation's type and age.

Periodic audits shall be compulsory for all electrical installations, except for private houses, apartments, holiday homes, and the buildings serving them, if they are not used for economic purposes.

Periodic audits have to be carried out recurringly at specific time intervals:

  • once every five years for the first type of electrical installation;
  • in the case of electrical installations of the second type, once every ten years;
  • for class 3 installations, once every 15 years.

For electrical installations built or rebuilt before 2000, a periodic audit must be carried out at the following intervals:

  • once every three years for electrical installations of the first type;
  • for class 2 electrical installations, once every five years;
  • every ten years for class 3 installations.

By way of derogation, a network operator operating under the Electricity Market Act and a producer subject to the authorization may, provided that the continuous maintenance and upkeep of the installation and its proper operation are ensured, carry out a periodic audit of the installation every 15 years.


The measurements used in the audit may be carried out by an accredited laboratory or a laboratory assessed as competent under the Measurement Act. Accreditation is carried out following EVS-EN-ISO 17025. The Estonian Accreditation Centre carries out certification and recognition. The accredited and professionally qualified measuring laboratories are listed on the Estonian Standards and Accreditation Centre www.eak.ee.

Guidance material for electrical installation audits

Electrical installations must not give rise to unacceptable electromagnetic disturbance when used under their intended purpose and in the manner intended and must be inherently immune to such disturbance. The electromagnetic compatibility requirements derive from Directive EMCD 2014/30/EU. The electrical installation shall be constructed following good engineering practice and taking into account information on its components' intended use. This good engineering practice shall be documented and kept available throughout the lifetime of the electrical installation. Electrical equipment and installations shall be presumed to comply with the electromagnetic compatibility requirements if they meet the relevant electromagnetic compatibility requirements set out in harmonized standards.

Where equipment likely to cause electromagnetic disturbance is installed or intended to be installed in an electrical installation, an additional assessment of electromagnetic compatibility shall be required. Such further review may be carried out by bodies accredited for electromagnetic compatibility. For example, an additional electromagnetic compatibility evaluation may be necessary if:

  • telecommunications and telecommunications installations;
  • charging stations for electric transport (cars, forklifts, etc.);
  • installations incorporating frequency-controlled industrial electrical equipment (cranes, lifts, escalators, conveyors, pumps, etc.),
  • power generation installations (including inverters),

and where the design or other documentation relating to the electrical installation of such an installation does not include measures to limit electromagnetic disturbance.

Depending on the nature of the installation and the equipment used, the measures to limit interference may vary, but the main ones are:

  • the use of shielded conductors, 
  • additional grounding and equipotential bonding measures;
  • the layout of conductors, e.g., placing conductors as close together as possible, increasing the cross-section of conductors;
  • use of filters.

The protection zone of an electrical installation is the area of land surrounding the installation where the property is restricted to ensure the safety and protection of the installation.

The following is forbidden within the protection zone of a building:

  • endanger the building or its normal use;
  • the construction of any other building requiring a building permit, including the removal and piling of soil;
  • to obstruct access to the building
  • obstruct the maintenance of the building;
  • to prevent the maintenance of vegetation or ground within the protection zone in a condition that does not endanger the building.

The extent of the protection zone of an electrical installation

The area of the protection zone of the overhead line is on both sides of the line:

  • 2 meters for lines up to 1 kV;
  • for lines between 1 kV and 34 kV, 3 meters in the case of overhead cable;
  • for lines with a voltage of 1 to 34 kV, 10 meters;
  • 25 meters for lines with a voltage between 35 and 110 kV;
  • 40 meters for 220-330 kV lines.
  • In the case of an overhead line mast bend or support (extending outside the overhead line's protection zone), the mast bend or support's protection zone shall be 1 meter from its projection on the ground.

The protection zone of an underground cable line is the area along the cable bounded on both sides by notional vertical planes 1 m from the line's outermost cables.

Around substations and switchgear, the protection zone extends to a distance of 2 m from the boundary fence, wall, or, in their absence, the equipment.

Last updated: 07.04.2021