Yes you can. The proper wiring of a switch is to bring the hot wire to the top of the switch terminal and connect the load to the bottom of the switch. When the breaker is turned off it disconnects the voltage from the top of the switch and the switch is then safe to work on. By not turning the breaker off, the voltage is present at the top of the switch which could subject you to a nasty shock if you come into contact with it.
No
Circuit breaker or switch
shut off the power to the box, switch out the breaker and resture the power
It is a relay or switch problem. A circuit breaker or fuse won't keep a light on.
A short circuit in the wiring or in the switch.
plastic is an insulator so it keeps you from being electrocuted.
Switch your main breaker off.
You may need to first switch it on before off.
Circuit breaker or switch
shut off the power to the box, switch out the breaker and resture the power
It is a relay or switch problem. A circuit breaker or fuse won't keep a light on.
A breaker switch is easier to use.
Switch off incomong water, screw old device out, then new one in, switch on again
A short circuit in the wiring or in the switch.
You need to turn off the power at the circuit breaker.
Turn the thermometer switch to offTurn the electrical service switch by the furnace to offTurn off the main breakerAfter turning off the main breaker disconnect the power line to the furnace
Yes it is possible.
An electrical switch which automatically shuts off when amperage get above a given value.