The wiring in most homes consists of three wires Two wires make up an electric circuit What is the purpose of the third wire?

Answer 1

ground circut

Answer 2

The third wire in wiring systems typically serves as a ground wire to provide a path for excess electrical current to safely dissipate into the ground. This helps protect against electrical shock and fire hazards by providing a low-resistance path for current to flow in the event of a fault.

Answer 3

A short answer to this question is: the purpose of the third wire is that it is installed to provide a safety wire that will carry any ground current if a fault condition occurs.

For more complete information please see the answer to the Related Question shown below.

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There are two main types of cables used in home wiring for the secondary branch circuits. One is a two wire cable and the other is a three wire cable . Whenever these cables are referred to, the bare ground wire is not included in the wire count as it is not a current carrying conductor. Most predominant is the two wire cable used for most circuits. The use of the three wire cable is for split kitchen receptacles and wiring of three way switches. In a big sq foot area home, three wire cables are sometimes used to take two circuits to the other end of the house instead of using 2 two wire feeders. These types of circuits use the common white wire for the neutral and the red and black wires for the two hot circuits.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 4

A three wire 120/240 volt system is created by centre tapping a 240 volt coil. The two lines of the 240 volt secondary coil of a distribution transformer are designated L1 and L2. The centre tap of the 240 volt coil is designated N which stands for neutral. The neutral centre tap is grounded to zero potential earth. As the 240 volt coil is centre tapped it splits the coil into two equal halves. This creates a condition, by having the two coils in series with each other that the total 240 volts is also split into two dropping 120 volts across each coil. From L1 to N is equal to 120 volts. From L2 to N is equal to 120 volts. From L1 to L2 is equal to 240 volts. In North America this is the voltages that are used in home wiring. By centre tapping this secondary transformer coil it allows appliances of both 120 and 240 volts to be used simultaneously to operate in the home. Larger wattage demand loads are connected to the 240 volt connections while smaller appliance wattages are connected to either of the two 120 volt connections.

As you state only two wires completes a circuit but by this type of connection twice the amount of circuits can be obtained at the 120 volt level. On a distribution panel of 40 circuits you can have 40 - 120 volt circuits or 20 - 240 volt circuits or any combination of the two depending on the specifications of the equipment to be connected.

Answer 5

The standard colour coding for UK electrical wiring is: Live - Brown. Neutral - Blue. Earth - Green and yellow stripe.

Answer 6

ground current