What if the Start Capacitor Keeps Overheating in Your Washing Machine?

Starting Power

• Appliances driven by electric motors consume energy fastest during the start of the operation cycle. Bringing the heavy armatures of motors up to full speed quickly from a stationary start requires extra torque. The start winding and start capacitor of a motor provide that torque just long enough to bring the motor to nearly full operating speed. Centrifugal forces then throw switches on the armature that cut both the start winding and the start capacitor out of the circuit and power up the run circuit. The main winding and run capacitor provide more efficient operating power under load at full speed.

Running Problems

• The components in a motor's starting circuit operate under high power and heat quickly, but cut out of the circuit in only seconds and cool down between uses. Starting capacitors overheat if used to start a motor more than 20 times in an hour or if the start cycle lasts more than three seconds. Normal washing machine cycles stay within those limits, but overloading washers slows the start cycle and overheats the start capacitor. Corroded centrifugal switches on the motor also might not trigger at the right speed, causing the start cycle to work longer than normal.

Symptoms

• Start capacitors designed for short operating cycles use different construction than run capacitors designed to dissipate heat continuously. The plastic housing of a start capacitor melts or burns when the part overheats seriously. Hot start capacitors pushed beyond their limits can create smoke or a smell of burning plastic after the washing machine starts. In washing machines, motors stop and reverse direction when shifting from rinse to the spin cycle. Symptoms might appear periodically while the washer runs. Run capacitors can contain toxic liquids within sealed metal housings, but start capacitors use solid components and won't leak if the part fails.

Solutions

• If start capacitors overheat, check for other problems. Pressure switches should turn off the fill cycle when the tub contains enough water. Sticky switches might overfill the tub and put extra strain on the washer. Watch for telltale spills during agitation. Packing the washer tight with laundry increases the weight beyond the washer's limits and overtaxes the motor's start circuit. Washing the wrong products in a washing machine can overload the motor as it goes into the spin cycle. Items that hold too much water, such as down clothing or sleeping bags, might prevent the spin cycle from reaching full speed.