Issue link: https://read.dmtmag.com/i/205269
SERVICE & SET-UP This Could Also Be Very Shocking!! BY GEORGE PORTER Good and faithful readers of this column will remember last month we discussed electricity. What is the stuff and how does it work. Maybe more importantly; how do we work with it? You don't need to have a degree in electrical engineering to wire an outlet thank goodness, but you do need to remember "B to B" that would be black to brass for those of you who missed it. This is not a fashion statement; it matters because a mistake here could possibly "light up your life". This month, as promised, we will delve into how do you know if things are as they should be in the breaker box. One of the things about electricity is that in order to get a pretty good general idea of what to do, you need to probably know more than you think you have to The electrical formula is one of those things. It is a very simple bit of math that you have to know. Think of it as a numbers formula like 2 X 3 = 6. If you know any two of these three numbers you can always figure out the third provided you know how to multiply and divide. So suppose we only knew one side (2 X 3 = ?) One would hope that the public education system has equipped you with the tools to figure this out and the answer is 6. But suppose we only had the 2 and the 6 in the above formula and we wanted to find out the missing part? We would need to rearrange the formula to say 6 ÷ 2 = ? By moving the numbers around we arrange the formula to yield the answer at the end; we really haven't changed the way the thing works. Using this simple little numbers example will help keep it straight in your head. Now the harder part: AMPERE: The flow of electrons through a conductor. The conductor is usually a wire and amperes are commonly known as amps. VOLTS: Voltage is the load of potential energy being carried by the electrons. WATTS: A measure of the total energy consumed. To figure out how much electricity you are NOVEMBER 2013 12 THE JOURNAL using it is necessary to use a basic formula. AMPS X VOLTS = WATTS or WATTS ÷ AMPS = VOLTS or WATTS ÷ VOLTS = AMPS Using this one formula (the above is one formula stated three different ways); you can determine how much the power consumption is on a single circuit. For instance if you had a television and four light bulbs on a living room circuit it is possible to find out how much power the TV and all the bulbs use. Then you know what else can be added to that circuit without causing an overload. On the back of the TV is a plate that gives the wattage of the appliance and on the top of every light bulb is its wattage. A color TV can be anywhere from 200W to 4500W so let's just say ours is 1000W. If we also have four 100W light bulbs then the total wattage on that circuit, if everything is turned on at the same time, is 1400W. Circuits are fused according to amps. When you exceed this load limit, the fuse will blow or the circuit breaker will pop which means the circuit is overloaded. It is necessary to convert this 1400W into amps. The voltage on this circuit is 120V as are most of the circuits in the home. Only large consumers of electricity such as clothes dryers or water heaters use a circuit that carries 240V. Using the third form of the formula, we divide the watts (1400W) by the volts (120V) and we get the amps (11.7A). This circuit breaker is rated for 15 amps so it is fine. Some of the other circuits in the home might be rated for 20A. However, if all four lights and the TV are on and the home-owner decides to run a vacuum cleaner (500W), it causes trouble. Now there is a total of 1900W on the circuit and dividing the 120 volts into this, you get 15.8 amps. If there is only a 15 amp circuit breaker in the box for this circuit, it will "pop," and the lights, TV, and vacuum will go off. Some people think the solution to the problem is a larger fuse. NO! That size fuse was installed in that circuit because it needs to be the weakest point in the system. Heat is generated in the conductor (wire) when the wattage goes up. If the fuse doesn't melt first and break the circuit, then the wire could get hot enough to start a fire in the wall. This type of fire is not a rare occurrence and you certainly do not want to be the cause of it. The solution in this case is to simply turn off two 100W light bulbs and everything will be fine. The amperage drops down to 14.2A and the circuit breaker or fuse will not blow. The point here is that just because the breaker pops does not mean that something is not working correctly. The exact opposite is probably the case but you don't know until you add up the load. This type of problem is handled the same in any home, but manufactured housing has a few rules that apply to it in particular. The grounding system is a major difference. This industry uses two grounds. One is the usual green wire that goes to the electrical system the same as all other types of wiring. The other is a ground that connects the frame and other metal parts of the home. The four wire system is unique to the industry and all 220 volt appliances use a special four prong plug. T J George Porter is a consultant to the manufactured housing industry. His Company is Manufactured Housing Resources, P.O. Box 863, Rehoboth Beach, DE 19971, (302) 645 5552, Web: www.georgeporter.com Some of his services are both in person and On-line training for certification in many states plus expert witness and investigation for the industry.