How to Disassemble Major Appliances
Before you can repair a major appliance, you'll have to disassemble all or part of it. All major appliances are different, but the disassembly procedure is about the same: Remove the parts in reverse of the way the manufacturer put them together. Check your owner's manual for assembly diagrams and instructions. Remember that you'll have to put the appliance back together again, so lay the parts out in the order in which you remove them, with fasteners in hand. If you aren't sure you'll be able to put the appliance back together, take notes and make drawings as you work. Label all terminals and wires if you must disconnect more than one wire at a time.
To disassemble a major appliance, start with the obvious knobs and fasteners. Many knobs and dials are push-fit. Simply pull them off their control shafts. Knobs may also be held in place by setscrews, springs or spring clips, or pins; or they may be screwed on. All of these types of fasteners are easy to release. Housing panels are usually held by screws or bolts. They may also be held in place by tabs. Sometimes, parts are force-fitted and may be hard to remove. Never force parts apart; look for hidden fasteners. For instance, there may be no obvious fasteners holding the top of a washer in place. However, you can locate the clips that hold the top of the washer down by sticking the blade of a putty knife into the seam where the top panel meets the side panel. Run the knife along the seam until you hit an obstruction; this is a spring clip. To release the clip, push the blade of the knife directly into the clip, at a right angle to the seam, while pushing up on the top panel. Repeat this procedure to locate and remove any other spring clips holding the top panel in place. Then lift the panel off.
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Fasteners may also be hidden under a nameplate or company logo, behind a scarcely visible plastic plug, under a cork pad on the bottom of the appliance, or under an attachment plate. Carefully pry up the part that is hiding the fastener. When you reassemble the appliance, snap the concealing part back over the fastener, or, if necessary, glue it into place. If you can't find hidden fasteners on force-fitted parts, warm the parts gently with a heating pad; the heat may make disassembly easier. Inside the appliance, watch for clips holding parts to the housing panel.
Before reassembling a major appliance, carefully vacuum inside the appliance to remove all dust and lint. Check for other problems and make any necessary repairs or adjustments. If the appliance has a motor, lubricate the motor. Check carbon brushes in universal motors for wear and replace them if necessary. Lubricate moving parts sparingly and make sure electrical contacts are clean.
Reassemble the appliance in reverse of the way you took it apart. Never force parts together or overtighten fasteners. Make sure moving parts, such as armatures or gears, don't bind. After reassembly, connect the power and turn it on. If it makes noise, smells, or overheats, turn it off and disconnect the power. Then go back over your repair.
Grounding Systems
Many homes today are equipped with electrical outlets that have a three-wire system. The third wire is a grounding device and operates the same way as the grounding wire on stationary appliances. Large appliances, whose plugs have two blades and a prong, should be plugged into a grounded outlet or grounded with a special adapter plug. Caution: Never remove the prong from a three-wire plug to make it fit an ungrounded outlet; always use an adapter plug.
Proper grounding is vital for metal-framed appliances. If the insulation on the power cord of a metal-framed appliance (such as a washer or dryer) is broken or worn away at the point where the cord enters the frame, contact between the current conductor and the metal frame could charge the whole appliance with electricity. When this happens, dampness can cause a shock hazard even if the appliance is properly grounded. If you accidently touch a charged metal frame in a damp location or while touching a water faucet or radiator, the current would surge through you and could kill you.
There are three things you can do to eliminate this hazard. First, make sure your major appliances are properly grounded. Second, make sure that all appliance cords are in good repair, and that they are not chafing against burrs or rough spots where they enter the appliance frame. Third, add a ground-fault circuit interrupter (GFI or GFCI) to the circuit. GFIs are monitoring devices that instantly shut off a circuit when a current leak occurs. They are required by the National Electrical Code on all new 15-amp and 20-amp outdoor outlets and for wiring in bathrooms, where dampness is a common problem. GFIs are available to plug into existing outlets as adapters, to replace outlets, and to replace circuit breakers in the electrical entrance panel. A professional electrician should install the circuit-breaker type; you can install the other types yourself. Ground-fault circuit interrupters are available at electrical supply and home center stores.
Double-Insulated Appliances
In double-insulated appliances and power tools, the electrical components are isolated from any parts of the appliance that could carry electrical current. However, these appliances are not completely shock-safe. You should use caution with any electrical device. For example, never operate an electric drill while standing on a wet surface--and never drill into a wall where power lines may be present. Double-insulated appliances and tools should almost always be repaired by a professional, because the double insulation depends on a plastic housing and a plastic buffer between parts that carry electricity. If these plastic parts are not properly positioned, the appliance or tool could produce a harmful electrical shock. Appliances and tools that are double insulated are usually labeled as such.
As you've seen, proper safety around electricity is essential. In the next section, we will discuss how to repair power cords and plugs.