Electrical Safety Part 2

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THE FOLLOWING INFORMATION IS FOR THE PURPOSE OF HELPING A COMPETENT PERSON WORK SAFELY WITH ELECTRICITY. THE TECHNIQUES AND METHODS SHOWN HERE ARE NOT ALL THAT A PERSON MAY NEED TO WORK SAFELY AND THE ARTICLE DOES NOT INTEND TO IMPLY THAT THIS IS COMPLETE FOR ALL WORKING SITUATIONS. IF YOU WORK WITH ELECTRICITY AND ITS ASSOCIATED EQUIPMENT AND USE THESE TECHNIQUES AND METHODS, YOU DO SO AT YOUR OWN RISK.

THINGS TO REMEMBER TO WORK SAFELY WITH ELECTRICITY

1. ALWAYS ASSUME THAT EQUIPMENT OR DEVICES ARE HOT (electric power is ON and is present at the device or equipment).

 2. ALWAYS DISCONNECT, that is, turn off electricity to the devices and equipment that you are going to work on. You can disconnect the electricity by:

  • Unplugging cord and plug connected appliances.
  • Turning or flipping OFF switches on walls or other control devices.
  • Removal of fuses at main or sub panels. Some of these may still be found in older homes or combination switch or receptacle fusible boxes.
  • Turning or flipping OFF circuit breakers at main or sub panels. See article on Residential Overcurrent Devices.

3. Ensure that the electricity WILL NOT be turned on by self or other persons. This can be done in one or more ways.

  • Have someone stay at the location where the electricity is disconnected so that he or she will allow no one to turn the electricity on.
  • Some circuit breaker installations provide a slotted tab for the use of a lockout device at the circuit breaker, allowing no one to operate the breaker switch. In a home, you will probably not have this feature. If you do, a lockout device is a separate item that can be purchased.
  • Orally instruct others not to touch the switch you turned off. Tag the switch “DANGER” instructing others to “DO NOT TOUCH OR DISTURB SWITCH.” However, do not trust in tags alone.
  • Some wall switches can be taped temporarily off with black electrical tape. Only do this if the switch is in view of your work location.
  • Also, always use good common sense. If you are 100% sure that no one will turn the electricity on, then you may safely work on the device or equipment. However, rarely can you be 100% sure. In practice, apply at least two of the aforementioned security procedures and you should be safe.

THE FOLLOWING SHOULD ONLY BE DONE BY SOMEONE MENTALLY AND PHYSICALLY (DEXTERIOUSLY) COMPETENT.

In cases where you cannot trust anyone, you may need to physically open or remove the circuit breaker panel cover and disconnect the hot wire from the breaker terminal. First, switch off the circuit breaker of the circuit you are working on, before disconnecting the wire. A flat head or phillips screwdriver can be used to disconnect the wire. For additional safety measures, you may want to stand on a rubber mat or dry wood for insulation; especially if the ground is damp.

MAKE SURE THAT YOU AND YOUR SCREWDRIVER DO NOT COME IN CONTACT WITH ANY BUS BARS OR OTHER SCREW TERMINALS EXCEPT THE ONE THAT IS CONNECTED TO THE WIRE YOU ARE DISCONNECTING.

Bus bars are what the circuit breakers or fuse baseholders are connected to. Bus bars are HOT and you can receive an electric shock and serious burns if you touch one while you are grounded. You may touch the insulated part of the wire; it does not conduct electric current. You do not have to unscrew the circuit breaker terminal completely to remove the wire. When removed from the breaker terminal, tape the metal part of the disconnected wire with electrical tape; it is not to come in contact with any bus bars or terminals. Carefully move the wire out of the way in the box and reinstall the panel cover. When reinstalling the wire, apply firm pressure to the terminal screw on the circuit breaker, but do not strip it.

4. Test the device or equipment to make sure the electricity is OFF. This applies only to the circuit or circuits which you have disconnected power from. Other devices in the building location may still be hot.

  • You may purchase a voltage tester, which is very convenient to use, and a more accurate way to test. Be sure you read how to use the tester and do not test voltages above the voltage rating of the tester. Do not test fluorescent light sockets with these testers.
  • You may use an appliance that you know is in good working order. For example, you might plug an iron into a receptacle to test if the power has been disconnected from the receptacle. You might use a  portable lamp or a power tool to test the receptacle. If there was no power to the receptacle or outlet to begin with, remove the cover plate and test the terminals of the outlet for the presence of power using a voltage tester.
  • To test a ceiling light switch make sure you use a working light bulb. You may first test the light bulb in another lamp socket to make sure it is working. The switch can also be tested with a voltage tester by removing the switch cover plate and test the terminals of the switch. Place one lead of the tester to ground (ground wire or metal box) the other lead touching the terminal tested.

5. When you return to your work after a break, such as lunch, REPEAT STEPS 1 – 4.

By following these rules to the letter, you should never receive an electric shock by the electric utility service; provided you are working on the side in which the electricity has been disconnected (turned OFF) and that no one overrides the safety measures implemented.