The periodic inspection of electrical equipment is one way of ensuring the safety and security of the use of electricity at a property. Electrical installations can sometimes be quite old, if they have been maintained and they continue to meet the safety requirements of the time when they were installed.
The periodic inspection is a statutory obligation in the same way as a motor vehicle inspection, for example.
In the case of electric damage, neglecting the periodic inspection may have legal consequences and affect compensation under the insurance terms.
Periodic inspections are required for business, office, industrial and agricultural buildings equipped with 35 amperes (A) fuses and electrical installations larger than this.
The obligation does not apply to residential buildings, as such. However, a periodic inspection is required for installations located in residential buildings protected with over 35 A fuses that are not living quarters or other rooms that mainly serve for living. These may include business premises and offices, public places (such as restaurants, day-care centres, shops, or medical centres), etc.
In the Electrical Safety Act, electrical installations are classified in installation categories based on their inspection and maintenance programme requirements.
For electrical installations in use, periodic inspections must be carried out according to the installation categories as follows:
| Installation category | Installation | Inspection interval |
|---|---|---|
| Category 3 | Networks of electricity distribution network companies | 5 years |
| Category 2 | Installations including parts of more than 1,000 V; low voltage installations with a connection capacity of more than 1,600 kVA | 10 years |
| Category 1 | Electrical installations with main fuses of over 35 A (business, public, industrial and agricultural buildings, installations in public places) | 10 years |
In the Electrical Safety Act, the obligation to take care of the inspection is assigned to the possessor of the electrical installation. Usually, the obligation lies with the owner of the property and in the case of tenancy, with the party that is responsible for the long-term maintenance of the property. As a rule, the inspection is agreed and ordered by the owner of the property, the user of the property or a party that takes care of the maintenance of the buildings on behalf of the owner or user and is responsible for other daily administration and management duties.
The periodic inspection ensures that the use of the electrical installation is safe and the installation has been maintained appropriately. Maintenance of an electrical system involves monitoring the condition of electrical installations, electrical equipment and electrically operated machinery and servicing and testing them in accordance with the relevant instructions. Any faults or deficiencies that appear must be fixed quickly enough to ensure the safety of use.
A separate maintenance program for maintaining the safety of an electrical installation must be prepared for more extensive and technically challenging electrical systems (installation categories 2 and 3). In this case, special attention is paid during the periodic inspection to the implementation of the planned measures. Measures recorded in the plan include:
During the inspection, it is verified that the electrical installation includes the circuit markings, electrical drawings and diagrams, and instructions needed for its safe use. The inspection also verifies that the equipment needed for maintenance are available. If electrical installations have been extended or modified, attention is paid to the commissioning inspection reports prepared by the electrical contractor and delivered to the possessor, and it is verified that the necessary changes have been made in the electrical drawings for the property.
The electrical systems that are inspected vary in terms of their age, size and solutions, which affects the inspection sample at each time, i.e. which parts of the electrical installation are inspected. Usually, the inspection is based on spot checks, while being comprehensive enough with respect to the item being inspected and the documents available for the installation. The inspection is risk-based, i.e. it concentrates on the items that entail the highest risks. The inspector is familiar with safety matters and can identify risks, faults and deficiencies that cause an electrical or fire hazard.
The periodic inspection includes a technical inspection in which the inspector studies the safety of the electrical system through various inspection measures and measurements.
The technical inspection focuses especially on switchboards, the correct choice of protective equipment, such as fuses, and the integrity and cleanliness of parts of the electrical installation, such as wall sockets, switches and lighting enclosures.
A part of an installation or a piece of electrical equipment that is broken or in a poor condition can cause not only a hazard of an electrical shock, but also a significant fire hazard. A broken wall socket, light switch or the cover of a plug fuse in a switchboard may have a life-threatening live part that a user may come in direct contact with. When the inspector opens covers of switchboards for examination, they check for any faults that may cause a fire hazard, such as excessively heating components or unreliable electrical connections. Measurements are used to examine, for example, the condition and integrity of protective conductor circuits and grounding that are important for the functioning of protective equipment in the cause of a fault.
The system being inspected may include areas where special safety requirements apply to the electrical installations and equipment. Areas such as rooms with a fire or explosion hazard or medical facilities are always inspected as a part of the installation. The inspection sample is also carefully considered for these areas.
As a sign that an inspection has been performed, the inspector attaches an inspection sticker on the property’s main distribution board. The sticker can be used to verify that the periodic inspection has been carried out e.g. during a fire inspection or an occupational health and safety inspection.
The inspector enters any faults and defects found during the inspection with their grounds on a periodic inspection report, which is handed over to the possessor of the installation. The report is an administrative decision that is binding to the possessor. It must be kept until the next periodic inspection.
The possessor of the electrical installation must ensure that the defects indicated in the report are fixed. If necessary, e.g. in the case of an accident, it must be possible to demonstrate that the items entered on the report have been appropriately fixed.
The inspection operations required by the Electrical Safety Act is impartial and independent towards all parties of the inspection. Because of this, the inspector cannot fix or participate in fixing the observed defects.
In a normal situation, electricity is an unnoticeable form of energy. Its existence is often only noticed when it is missing completely or is already causing a hazard. The most important purpose of the periodic inspection is to prevent electrical damage, electric shocks, fires, and unexpected interruptions that often also have significant indirect cost effects.
However, the periodic inspections that are carried out at relatively long intervals are not solely enough to continuously maintain the electrical safety of a property; in-service monitoring, service and maintenance are also needed. Installations and equipment that are faulty or have reached the end of their service life must be repaired or replaced before they cause a hazard.
The inspection findings must be considered more widely than just as a requirement to fix individual faults and defects. The inspection result often indicates general deficiencies and needs for development in the long-term maintenance of the electrical safety of a property. It is highly advisable that the possessor of the electrical installation, their representative or another party responsible for the maintenance of the property participates in the inspection.
The observations made during the periodic inspection, together with the guiding and instructing operating manner of the inspector, provide a good picture of the current safety situation of the electrical system and the sufficiency and level of maintenance. This information helps in anticipating risks caused by electricity and developing maintenance procedures.
The Occupational Safety and Health Act requires that employers ensure the safety and health of employees during their work through appropriate measures. Among other things, employers must ensure that the occurrence of hazardous and adverse factors is prevented and those that occur are removed. A working environment that is safe in terms of electricity and the prevention of hazards caused by electricity belong to occupational health and safety operations. Therefore, employers should ensure that the electrical installation of the workplace is maintained in good condition and required periodic inspections are carried out in time.
Statutory periodic inspections are carried out by authorised bodies and inspectors. The Tukes website contains a list of operators offering inspection services (xls, 81 kt). In addition, the website of the SÄTY Electrical Inspection Association contains a list of inspectors that are members of the association together with their contact details.
The key regulations and instructions concerning the inspections can be found on the Tukes website. (Tukes guidelines: Sähkölaitteistot ja tarkastukset, pdf, 274 kt and the guide Kiinteistöjen sähkökunnossapito ja määräaikaistarkastukset, pdf, 216 kt)
Electrical safety specialists may also offer services other than statutory inspection services, provided that the impartiality and independence of the inspection operations are not compromised. The possessor of a property can choose to order a voluntary inspection, other investigation or a specialist’s statement for their electrical installation. In such a case, the contract between the possessor and the inspector will define the scope and content of the assignment.
A voluntary inspection can be carried out for the electrical installation of a house or apartment if there is a need to ensure its safety for any reason, for example. Any suspicious installation work, abnormal operation or frequent faults appearing in electrical installations are a good reason to commission a voluntary inspection or other investigation.
An inspection of the electrical installation may be justified and advisable in connection with the sale of a home or a property, especially with older properties.
A specialist service can be requested in cases where it is necessary to estimate the remaining service life of electrical installations to support the investment and renovation planning of a housing company’s board.
Inspection bodies may also offer additional services, such as the measurement of the quality of electricity or thermal imaging. The use of a thermal imaging camera has been found to be a good measure to be included in maintenance operations. It can detect the early development of faults and prevent unexpected faults that may potentially cause a fire hazard.
