Being able to tell whether a wire is hot or neutral is an essential skill and a life saver for electricians – the wires that have electrical current passing through need to be treated differently from a safety point of view and they need to be correctly used when connecting pieces of equipment as well. There are several ways to find out if a wire is live – here they are:
– Identification by the color of the wire – the National Electrical Code assigns certain colors for hot wires to allow electricians to safely identify the path of the current by simply looking at the wires. In residential applications, black and red wires are hot. However, color coding is not always reliable, especially when the appliance is older, so further checks by companies like JM Electric Inc. are usually required;
– Use a multimeter – a multimeter is a measuring device that has probes for performing various checks. To check whether a wire is live, set the multimeter dial to 250 AC, then touch the wire with one probe and a metal object with other probe. If the wire on a small household application is live, the reading will be between 110 and 120 V, while for larger appliances, the reading will be 240-250 V. For neutral wires, the reading is zero.