GFI receptacles main role is to protect people from getting shocked. They have special sensors which measure the balance between neutral and hot wires. In other words, it senses that there is electricity currently going somewhere it should not i.e., though your body (it can save your’s kids live in emergency situations)
It is really sensitive so it will open in a matter of milliseconds when is probability of fault. The typical fault sensitivity is set at level which small child is able to survive.
Typical faults are caused by water, bad wiring or tear in insulation of wire. Particularly they should be installed where is a lot of moisture like bathroom or outdoor receptacle.
One of the great features of GFIs is that they protect a string of receptacles – one device can protect all plugs in your kitchen for example.
GFIs are required especially in bathrooms, kitchens, outdoor or in all ungrounded reeptacles. It is not required by the Ontairo Electrical Code to replace all of plugs in locations mentioned above, unless the devices are being changed for other reasons, but for safety reasons of your family I recommend changing them as it is possible.
The other use of GFIs is a possibility to legally replace two prong receptacle (ungrounded) for three prong receptacle aside from rewiring the existing circuit.
GFI breakers can go to existing electrical panel, these cost $55 and up, comparing to GFI receptacles which start from $12 and up.
There are two buttons on the receptacles first one is a test button (it pop when pressed, which causes the plug to energize)
The other button is so called “the rest button”, which turns plug on. In case when button does not work I recommend to contact an electrician to check it.