How Your GFCI Outlet Works and Why You Need It

The GFCI is designed to notice the difference in the amount of electricity flowing into the circuit to that flowing out, even in amounts of current as small as 4 or 5 milliamps. The GFCI reacts quickly (less than one-tenth of a second) to trip or shut off the circuit.  In Ontario the ESA has specific rules which identify where GFCI outlets are required to be installed.

GFCIs are generally installed in high risk areas where electrical circuits may accidentally come into contact with water. They are most often found in kitchens, bath and laundry rooms, or even out-of-doors or in the garage where electric power tools might be used.  Tap water or wet objects are able to conduct electricity very easily and can connect your body to a ground potential, thus increasing your chances of receiving a shock from a ground fault. Appliances that have built-in GFCI protection, as now required for hair dryers, may not need additional GFCI protection, but there are still many appliances not equipped with GFCI protection.

Testing Your GFCI Outlet

GFCIs should be tested monthly to ensure they are in working condition. Whether you have a receptacle or circuit breaker GFCI, pushing the TEST button should turn off the power to the circuit. For the receptacle-type GFCI, pushing the TEST button should cause the RESET button to pop up. (Remember to push the RESET button to re-establish power and protection.) For the circuit breaker-type GFCI, pushing the TEST button should cause the handle to move to the tripped position. (Remember to reset the handle to re-establish power and protection.)  Testing your GFCI outlet

Bathroom GFCI Outlet Required

A ground fault circuit interrupter (GFCI) should be in all bathrooms. GFCIs protect us from receiving electric shocks from faults in the electrical devices we use in our home. It works by comparing the input current on the hot side to the output current on the neutral side. A GFCI is required within 1.5 meters of a water source. If water gets into the receptacle, it will shut down the power to the receptacle so that the outlet cannot be used.

Kitchen GFCI Outlet Required

Since 2003 any outlet in kitchen that is within 1.5 m of water, sink etc, is required to be GFCI protected. Since 2005 any fixed island counter is require to have an outlet installed.  GFCI is required if sink is installed in island and outlet is within 1.5 m of sink.  If your island has plumbing, dishwasher, wine cooler or fridge it would be considered immovable and require an outlet.  ( consult with ESA for specific rules regarding size of work area etc. )

The American Electrical authority, the NEC has published a guide for effective dates when GFCI were required.  Unfortunely they do not match up with Ontario’s Effective Dates but can be used as an example of the progression of requirements for GFCI outlets.

NEC GFCI requirements (and effective date):GFCI Electrical Wiring

Underwater pool lighting (since 1968)
Outdoors (since 1973)
Bathrooms (since 1975)
Garages (since 1978)
Kitchens (since 1987)
Crawl spaces and unfinished basements (since 1990)
Wet bar sinks (since 1993)
Laundry and utility sinks (since 2005)

Why a GFCI might Trip without Cause

It takes only 5 mA (0.005 A) of current leakage from the hot wire to the ground to cause a GFCI to trip. A small amount of leakage current may be difficult to avoid in some normal circuits. Hand-held power tools do not cause a tripping problem if the tool is maintained in good condition. Some stationary motors, such as a bathroom vent fan or fluorescent lighting fixtures, may produce enough leakage to cause nuisance tripping. Another problem may be a long circuit with many splices. If possible, keep GFCI circuits less than 100 feet long. To avoid nuisance tripping, a GFCI should not supply:

  • Circuits longer than 100 feet
  • Fluorescent or other types of electric-discharge lighting fixtures
  • Permanently installed electric motors

The GFCI  outlet requirement and testing is just one of the hundreds of items the Orillia Home Inspector inspects when performing a Home Inspection on your new property.  With over 20 years of actual Home Inspection experience and over 9,000 inspections completed you can put your trust in our services.

Free Thermal Imaging with an Infrared Camera is also offered with every Home Inspection.  Thermal technology can identify hidden moisture, missing insulation and electrical hot spots.