China
Africa
Explore chapters and articles related to this topic
Learning Outcome 3
Published in Kevin Smith, Get Qualified: Portable Appliance Testing, 2016
The term ‘separated’ refers to the fact that the wiring in a SELV system is electrically separated from earth, making it impossible for the user to receive an electric shock by only touching one conductor or live part while in contact with earth. A shock is, however, still possible if the user simultaneously touches both live conductors. In addition to electrical separation, ELV systems operate at voltages not exceeding 50 V AC or 120 V DC either between conductors or to earth. In the case of SELV the operating voltage is limited for safety reasons and improves protection in the event of electric shock.
The UK Generation, Transmission and Distribution System
Published in Brian Scaddan, IET Wiring Regulations Electric Wiring for Domestic Installers, 2018
Voltage band 1: Extra Low Voltage (ELV) which does not exceed 50 Vac. In domestic installations ELV is used for bell and call systems, 12 V lighting (incorrectly called low voltage lighting by manufacturers) and for some circuits in bath/shower rooms, where it is Separated Extra Low Voltage (SELV). See also Chapter 4 Bathrooms.
Tapboost - the design for manufacture of a low voltage water pump to boost the poor domestic water flow rate
Published in Australian Journal of Mechanical Engineering, 2023
As the motor used is Safety Extra Low Voltage (SELV) 12 V, it cannot be powered by an ordinary mains power supply at 230 V. The voltage going into the pump must be regulated this means that the motor can either be powered by batteries or by a Power Supply Unit (PSU) which regulates the 230 V supply from the mains down to 12 V going into the pump with a transformer pack. Battery operation of the product would be a cheaper solution, but it also means that the customer would have to replace the batteries repeatedly to keep the pump powered.