The LVD Low Voltage Directive (2014 / 35 / AB) mainly covers low voltage devices. Low voltage is defined as follows in accordance with the principles of this regulation:
- Between 50 Volts and 1000 Volts for alternating current
- Between 75 Volts and 1500 Volts for direct current
Direct current occurs when the electric charge always flows in the same direction. In alternating current, the current direction is reversed at equal time intervals. Therefore, the generation, transmission and use of these two different currents are different from each other. It is possible to convert these two different currents to each other using various electronic circuits.
Electrical energy is produced by converting different energy sources by various methods. For example, electricity is generated from renewable energy sources such as solar, water, wind or geothermal, or from fossil-based, non-renewable energy sources, such as petroleum, coal, oil, natural gas or nuclear. The resulting electric current may be alternating current or direct current. It is most commonly produced in direct current chemical cells, solar cells and dynamos. Alternating current is generally produced in alternating current motors.
A significant portion of the electricity used is obtained by first converting it into motion energy and then converting it into electrical energy depending on the energy source. Alternating current motors are generally produced at a lower cost than direct current motors, are easier to maintain and operate with higher efficiency. Therefore, alternating current is preferred in electrical devices and equipment.
LVD tests, that is, low voltage tests, are carried out on all electrical devices and equipment designed and manufactured to work with low voltage in accordance with the regulations in question. However, some devices and equipment are excluded from LVD tests in the annex to the regulation (Annex 2). Therefore, LVD tests are applied to all devices other than those listed below and operating with current within the limit values described above.
Devices, equipment and situations for which LVD tests will not be performed are:
- Electrical devices designed and manufactured for use in explosive atmospheres
- Electrical devices designed and manufactured for use in radiology and medical purposes
- Electrical components of cargo and passenger elevators
- Electricity meters
- Household plugs and sockets
- Electric fence controllers
- Radioelectric interference
- Electrical devices specially designed for use on ships, aircraft and railways and in compliance with international safety regulations
- Specially designed evaluation kits for use in research and development facilities by qualified personnel only