How do you hook up a new range with a four-prong cable if the range you are replacing only has a three-prong cable?
For USA, Canada and countries running a 60 Hz supply service. Your old range didn't require a neutral but your new one does... So, if you are upgrading your range, you must… upgrade the wiring to it. Such an old-fashioned range circuit really needs to be upgraded all the way from the breaker box: a pair of new breakers to a common-tie two pole breaker, a new length of correctly-sized cable (with red and black hots, white neutral and bare ground) and a new 4-wire outlet. If you're not sure about the latest wiring codes or regulations that apply to where your home is, it is best to ask a professional Licensed Electrician for advice or to do the job for you. Nooo... it's the Ground the old range may not have been connected-to. There's always a neutral line, but for a very long time you weren't required to ground ranges in site-built dwellings. (You had to ground the range in a mobile home. I have no idea why there was a disparity.) [Update: It was because they more more likely to have damp or wet walls and floors - a real health hazard.] Basically, you need either new range circuit wiring and 4-prong outlet (the preferred method -- installing a 4-prong outlet will bring your house up to code in that one part of its electrical system) or a new 3-prong cord. If you decide to keep the old range circuit wiring and 3-prong outlet you must change the cord on the new appliance from 4-prong to 3-prong. Then you must connect the frame of the new range either to the existing separate ground wire, if there is one - it is either green-sheathed or bare copper - or , if there is no existing separate ground wire, you must ensure that the frame of the new range is connected to the neutral line by using an internal frame-to-neutral tie strap. BUT first of all - before you do that - you must consult your local Electrical Safety Inspection Authority - or a local licensed electrician - to find out if it is still legal to use a 3-prong cord with no separate grounding conductor where you live. If you needed to ask this question here the best advice anyone should give you is to call in an experienced electrician to ensure this work is done correctly either way. It's not very expensive and it will help ensure that your own life - and that of any members of your family, visitors or future home owners - will stay safe. It may be worth noting that, in some very old homes, a 220-240 volt range circuit may have no neutral wire, just two "hot" wires. They might even have just a big 2-prong plug and socket and a completely separate ground wire directly connected to the frame of the range. A lot of those range circuits were updated - many years ago - to the many 3-prong plugs and sockets you still see today, which have now been superceded by the present 4-prong plug and socket outlet which is specified in the NEC. (The N ational E lectrical C ode). The two 120 volt hots might be colored either "red and black", "black and black", or "red and red". The ground wire might be just bare copper or be covered with green insulation. That kind of circuit cannot safely supply a modern range which needs 240 volts for the heating elements and 120 volts for the clock/programmer and a 120 volt socket if there is one on it. Cable sets for dryers and ranges - or for that matter any three wire cable sets - all have bare copper ground wires in them. For proper fault protection, this bare copper ground wire is sized in relationship to the current-carrying wires. (LIFE SAFETY WARNING! [disclaimer] Electricity is dangerous! You can be injured or killed! Improper installations can cause fire, injury and death! Should you be doing this yourself?) TURN THE POWER OFF! CALL AN ELECTRICIAN! This is one of the most commonly asked questions in FAQ forums about electricity and wiring. It must be understood that new appliances will be designed to meet the newest standards. It is not reasonable to expect someone to rewire their home because they need a new dryer or range! [stove] According to the NEC [National Electrical Code], in many places in the US it is now required to isolate the neutral conductor from the appliance frame or chassis. It used to be allowable to use the neutral as a means of grounding by incorporating a link between the neutral and the chassis. The problem with this is that, should the neutral become "open" at some point, the chassis or frame then becomes energized! The answer to this safety issue was to require a separate grounding conductor in the cable feeding the appliance. The old 3-prong method can still be used in certain localities (states/towns) so, unless you are already qualified yourself (in which case you would not be asking this question here!) you must consult your local Electrical Safety Inspection Authority - or a local licensed electrician - to find out if it is still legal to use a 3-prong cord with no separate grounding conductor where you live. For more information see the answers to the Related Questions shown below. 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. (MORE)