How do you identify the white - neutral - on a two prong extension cord?

Answer 1

Answer for USA, Canada and countries running a 60 Hz power supply service.On a 120 volt 15 amp receptacle: with the U shaped ground slot on the bottom you will see two parallel slots above it. The right smaller slot is connected to the hot wire and the left larger slot is connected to the neutral. On the back of the receptacle there are three screw terminals. The ground wire goes on the green screw, the black wire goes on the brass screw and the white neutral wire goes on the silver coloured screw. Answer for Britain and Ireland and other world areas running the same standard 50 Hz supply service. British 'receptacles' are called 'socket outlets'. They are rated at 230 V / 13 A, and generally supplied directly from a ring main or from a spur, connected to a ring main. Most commonly, they are switched, but some (e.g. those supplying a freezer) are unswitched. All are shuttered, to prevent access to the line and neutral connections whenever the plug is removed. The shutters are operated by the plug's earth (ground) pin, which is longer than the line and neutral pins. The line and neutral pins are often partially-insulated to prevent access to live pins as the plug is withdrawn. The right-hand shuttered slot is the location of the line connector; the left-hand shuttered slot is the location of the neutral connector. Both slots are identical in size because polarisation is unnecessary, as all 13-A plugs are three-pin types (no two-pin plugs are manufactured for this type of socket).

At the back of the socket outlet, the line terminal is identified with the letter 'L' and the corresponding conductor's insulation is BROWN. The neutral terminal is identified with the letter 'N', and the corresponding conductor's insulation is blue. The earth terminal is identified with an earth symbol, and the corresponding conductor is usually bare copper wire but, to comply with the wiring regulations, should always be covered with green/yellow striped insulation wherever it is connected to terminals in socket outlets, junction boxes, cicuit breaker panels, etc.

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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 2

The only cord with a rib identifier is lamp cord. There are small extension cords made of this material but should only be used for very light duty such as extending table of floor lamps so that they can reach existing wall receptacles. This rib identifies the neutral conductor so that the lamp get wired with the correct polarity. The rib connects to the plug's neutral blade (silver screw). At the lamp end the rib wire connects to the lamp holder's shell. The shell is the part that the light bulb screws into. The white wire (neutral) on a two blade extension cord is the side with the raised rib.