Electricity: Receptacles

120/240-volt, 30-amp grounded receptacle for clothes dryer

A 120-volt, 15- or 20-amp duplex receptacle consists of two receptacle outlets, each accommodating a standard 120-volt plug. For new installations, three-slot grounding type receptacles are required. Three-slot receptacles should be used to replace old two-slot receptacles if the new receptacle can be properly grounded (more info). Receptacles have screw terminals and /or push-in terminals. A duplex receptacle has silver-colored screws for connecting neutral wires, brass-colored screws for connecting hot wires and a green grounding screw for connecting grounding wire. Break-off tabs between the outlets allow you to split- wire a duplex receptacle to supply each outlet from a different circuit. Another option is to control the lower outlet by a wall switch, with the upper outlet hot all the time. Make sure the ampere and voltage ratings of new replacement receptacles match those of the old receptacles.

Large appliances often require 240- or 120/240-volt receptacles rated 30 amps or more. A receptacle’s ampere and voltage ratings determine its slot design, which must match the configuration of the appliance plug. (Image on right is a 120/240-volt, 30-amp grounded receptacle for clothes dryers).

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Replacing a Receptacle

Defective or worn receptacles won’t hold a plug properly or may cause circuit failure whenever you plug in an appliance. To replace, turn off power to the circuit and check the receptacle using a tester. Connect wires to new receptacle, restore power and test receptacle.

A middle-of-circuit receptacle is connected to incoming and outgoing cables. Pigtailing the hot and neutral wires similar to the ground wire is preferable.

In an end-of-circuit receptacle the grounding wire connection is pigtailed because there is only one ground screw on the receptacle. (cont.)

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Installing a GFCI Receptacle

Installing a GFCI Receptacle

Ground-fault circuit-interrupters (GFCIs) have saved countless lives. They prevent lethal shocks by stopping cur rent flow within 25 milliseconds if they sense ground-fault current of 5 milliamps. GFCI protection devices include circuit breakers, receptacles and portable devices. GFCI protection is required for receptacles installed outdoors and in bathrooms, garages, accessory buildings, crawl spaces, unfinished basements, kitchens and wet-bar areas (Canadian requirements differ). It’s also required for hydromassage bathtubs, spas and swimming pool areas. Read all instructions carefully and test GFCIs monthly (image, far right).

Last modified: Saturday, 2007-11-03 1:13 PST