GFCI – Ground Fault Circuit Interrupter

How GFCI Works

Living with Electricity – “What is a GFCI?” Why it matters and how it works.

The term “GFCI” is short for Ground Fault Circuit Interrupter, a requirement of the Canadian Electrical Code to circuits and appliances in your home from the risk of electric shock. Conventional circuit breakers and fuses are not capable of protecting you or your family from electrocution. GFCI devices do not offer 100% protection from electric shock but do significantly reduce the risks.

GFCI’s monitor the imbalance of current between the ungrounded (Hot) conductor and the grounded (Neutral) conductor of a circuit. It opens the circuit when it detects a current flowing along an unintended path. Reducing the risk of being lethally shocked due to faulty wiring and appliances or where moisture may be present.

GFCI circuit breakers & receptacles are required at the following locations:

  • Interior receptacles adjacent to sinks and in bathrooms.
  • Outdoor receptacles powering portable lighting, power washers or tools.
  • Jacuzzi’s / hot tubs, swimming pool pumps, adjacent pool lighting and water feature pumps, to name a few.

These devices are either fixed or adjustable to levels from 5 to 20 Milliamps. (5 Milliamp is required by the CEC for most household systems.)

Do I have adequate GFCI protection? It’s vital to test your GFCI devices regularly, most manufacturers recommend you perform a monthly test to ensure they trip and re-set properly. If you haven’t done so in a while … or ever, it’s time you do! Higher risks are in older homes or DIY/Handyman electrical renovations” if this describes your home you should immediately seek out the advice of a Qualified Licensed Electrician to determine if you have adequate protection.

Testing is simple and straightforward. Follow the procedure which should be posted on your panel. GFCI devices have a test (trip) and re-set function for testing. Depress the (trip) and the device/breaker should OPEN.  If it opens, re-set (Close) and repeat… just to make sure it functions properly. If you discover your GFCI device is not testing properly you need to have it replaced.

A recent study has shown that when tested 19% to 21% of GFCI devices failed to perform properly. These failures are attributed to damage to the internal sensing devices from Voltage surges, overloading, ageing and/or lightning. Nothing lasts forever.

Never attempt to tamper with or modify electrical circuits unless you are experienced or qualified. Household voltages of 120 Volts and 240 Volts are extremely dangerous.

Live a Safe Life!

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