Inspections of electric appliances

The norm applies to:

• electrical equipment and machinery permanently connected
• electrical substations, cabinets, distributors
• electrical wiring, sockets, luminaires
• objects with protection against the effects of atmospheric and static
• electricity (lightning)

STN 33 1500 applies to all equipment which may endanger human health, livestock or property. The purpose of the professional inspection and testing of electrical equipment is to verify the safety condition of the equipment. The safety requirement is considered to be fulfilled if the electrical equipment complies with the relevant provisions of the standards in terms of safety.

Initial inspection: New electrical equipment may only be put into service if its safety status has been verified by an initial inspection and test.

Periodic inspection: Operable electrical equipment must be regularly inspected at the latest at the specified intervals (see table). The inspection must be carried out at the latest in the year in which the end of the prescribed period falls since the last inspection was carried out. Not valid for periods of less than 1 year.

Table of periodic revisions

ELECTRIC INSTALATIONS

Periods for periodic inspections set by the environment (STN 33 0300)

Type of environment (according to STN 33 0300)	Time limit [year]
Basic	5
Normal	5
Cold	3
Hot	3
Humid	3
Wet	1
With increased corrosive aggressivity	3
With extreme corrosive aggressivity	1
Dusty with non-combustible dust	3
With tremors	2
With biological pests	3
Passive with fire hazard	2
Passive with explosion hazard	2
Outdoor	4
Under shelter	4

Periods for periodic inspections determined according to the type of environment with increased risk to persons

Number	Location of electrical equipment	Time limit [year]
1	A place intended for the assembly of more than 250 people (e.g. cultural and sports facilities, department stores, public transport stations, etc.)	2
2	Brick-built residential and office buildings, Recreation centres, schools, kindergartens, nurseries, hotels and other accommodation	5
3	Recreation centres, schools, kindergartens, nurseries, hotels and other accommodation	3
4	Buildings or parts of buildings constructed of construction materials of flammability class C2, C3 (STN 78 0823)	2
5	Mobile and transport equipment	1
6	Temporary site installations 0,5	0,5 (6 months)

LIGHTNING RODS STN 34 1390

Periods for periodic inspections of equipment for protection against the effects of atmospheric and static electricity

Type of object	Time limit [year]
Buildings and premises with explosion or fire hazard environment, buildings constructed of construction materials of flammability degree C1, C2, C3	2
Other	5

ACTIVE LIGHTNING RODS (Pulsar) STN 34 1391:

Periods of periodic inspections of equipment for protection against the effects of atmospheric and static electricity protected by active lightning rods.

	Normal interval	Shortened interval
Class I	2 years	1 year
Class II	3 years	2 years
Class III	3 years	2 years
Other		5 years

The norm applies to:

• electrical household and similar appliances
• electric lamps
• electrical equipment for information technology
• consumer electronics apparatus
• moving leads and extension leads
• electrical and electronic measuring instruments
• other electrical appliances of a similar nature

The norm does not apply to electrical medical equipment, electrical equipment for mines, electrical equipment for explosion hazardous areas.

Electrical appliances and their use:

• 3.2.1 Non-portable appliance: an appliance that is not portable or an appliance that is fixed
• 3.2.2 Fixed appliance: an appliance that is intended to be used when fixed to a base or otherwise secured in place
• 3.2.3 Portable appliance: an appliance that is handled at work, or other than a fixed appliance, weighing less than 18kg
• 3.2.4 Hand-held appliance: a portable appliance designed to be held in the hand during normal use, the motor, if any, being an integral part of the appliance

Classification by use:

• A - provided in the form of a lease to another user
• B - used outdoors (construction, earthworks, etc.)
• C - used for industrial and craft activities indoors
• D - used in public areas (schools, clubs, hotels, etc.)
• E - used in administrative activities

Class of electrical appliances	Hand-held appliances (3.2.4)		Portable appliances (3.2.3)		Non-portable appliances and fixed appliances (3.2.1, 3.2.2)
	check	revision	check	revision	check	revision
A	Always before issuing to the user
B	before use	1x in 3 months	before use	1x in 3 months	before use	1x in 6 months
C	before use	1x in 6 months	before use	1x in 12 months	before use	according to STN 33200-6-61
D	1x in week	1x in 12 months	1x in month	1x in 12 months	1x in 3 months	according to STN 33200-6-61
E	1x in month	1x in 12 months	1x in 6 months	1x in 24 months	1x in 12 months	according to STN 33200-6-61

The inspection of an electrical appliance may also be carried out by an employee of the company who is authorised to carry out the inspection

During the inspection, the electrical appliance shall be thoroughly inspected from the outside:

• covers, handles, controls, etc. must not be damaged so as to reduce protection against dangerous contact
• the permanently connected movable cord must not have damaged, swollen or excessively hardened insulation, it must be secured at the entrance to the appliance by a protective sleeve (or, in the case of non-portable appliances, by a grommet) and must be secured against pulling out, the fork must not be damaged
• the extension or movable or detachable lead must not have damaged, swollen or excessively worn insulation

The norm applies to:

• electric hand tools

Classification of tools according to use:

• A – the tool is used only occasionally ( up to 100 operating hours per year)
• B – tools are used frequently for short periods of time ( 100 - 250 operating hours per year)
• C – the tool is frequently used for longer periods ( more than 250 operating hours per year)

Classification of tools according to protection class:

• I – the tool has a clamp for connecting the protective conductor
• II – the tool has double insulation
• III – the tool uses a safe voltage for its operation

Class	Protection class	Time Limit
A	I.	6 months
	II. a III.	12 months
B	I.	3 months
	II. a III.	6 months
C	I.	2 months
	II. a III.	3 months