As the name suggests, a safety switch is a device to switch off electrical supply in case of an electrical fault. It minimises electrical hazards like fires, electrocution, injury, and death. It is mandatory to install safety switches in all power systems in commercial buildings.
How safety switches work
A safety switch can detect the variation in the electrical circuit and automatically switch off the power supply in less than a second. Thus, if a person makes direct contact with electricity, and power passes through the body, the safety switch detects the variation and switches the power off. It is important to remember that while fuses and circuit breakers protect against short circuits and current overloads, safety switches protect people from electrocution. However, safety switches act as a back-up and may not protect all wiring and electrical appliances. Furthermore, they will not prevent all electric shocks.
Types of safety switches
There are different types of safety switches with different purposes and protection. The three main types of safety switches are:
- Switchboard safety switches – these are installed to protect electrical circuits, electrical appliances, and extension cords on individual circuits. They must be installed by a licensed electrician
- Powerpoint safety switches – they protect appliances and power cords plugged into the switch. They might protect other electrical wiring and power points on the same circuit
- Portable safety switches – these are essential protective devices for people working with power tools and other electrical appliances without any access to switchboard or powerpoint safety switches. However, portable safety switches will only protect from faults in the equipment directly plugged into them.
How to test a safety switch
Safety switches must be tested at least a couple of times a year to make sure that they are in working order. it is tested by pressing the test button. When the button is pressed, the safety switch must immediately trip to the OFF position. Then the switch is returned to the ON position. If the safety switch does not trip to OFF position during the test, turn off the power, and get the help of a certified electrician.
Safety switches in the workplace should be tested and records must be maintained for regulatory purposes. If the safety switch has tripped, it could be because of a temporary fault, lightning, or nuisance tripping. In such a scenario, resetting it can restore the power supply.
In case you are unable to reset a safety switch after it has tripped, it is possible that you have a faulty appliance connected to the circuit. It could be a wiring fault as well. If you suspect a faulty appliance, switch off and unplug the appliance. The safety switch can be reset, and power can be restored. If you are not sure of any procedure, it is advisable to get the services of a licensed electrician.