Figure 7-1. - Typical washer motor.
motor with pulleys, mounting bracket, and high-speed solenoid.
Pump. - The pump removes water from the tub after each cycle. Normally, the pump is located next to the motor and is engaged by the electrical solenoid. The solenoid engages the friction wheel of the pump (fig. 7-2) with the friction wheel on the motor, causing the shaft to turn the impeller and extract water from the tub. The discharge hose of the pump must be mounted above the water level of the tub, or the water will dram without the operation of the pump. In some cases, the pump is belt-driven and the solenoid tightens the belt to make the pump operate.
One of the major causes of pump failure is foreign objects lodged in the pump impeller. To correct this situation, you remove the cover clamp (fig. 7-2) and the cover and remove the lodged item from the pump. Other causes are slippage between the friction wheels of the pump and motor and failure of the solenoid. Also, check for clogged hoses leading to and from the pump.
Inlet Valves. - Water inlet valves equipped with two solenoids are called mixing valves. They have two water inlets: one hot and one cold. They actually mix hot and cold water. When the temperature control switch is set in the HOT position, the solenoid on the hot-water side of the valve is energized. That permits only hot water to enter the machine. Conversely, when the temperature control switch is set in the COLD position, the solenoid on the cold-water side of the valve is energized, and only cold water is permitted to enter. Positioning the switch in the WARM position energizes both solenoids, allowing hot and cold water to mix.
When water fails to enter the machine naturally, check the water supply first. Then check the screen at the inlet valve. At the hose connection to the inlet valve, there is a fine screen: make sure it is free of any foreign
Figure 7-2. - Pump assembly.
objects. Ensure that you have power to the inlet valve solenoid. Remember the electrical power must come through the water-level control switch, water- temperature selector switch, and timer.
As a last resort, disassemble the valve and check for foreign objects. Also, ensure that the plunger inside the valve is free to operate; there must be at least 10 pounds of water pressure to overcome the spring pressure of the plunger in the solenoid valve.
Water-Level Switch. - The water-level switch, normally actuated by pressure, controls the amount of water that enters the tub. The switch has an adjustment screw to set the level of the water. The tighter the screw, the more pressure is required to operate the switch, and the higher the water level required The water-level switch has two sets of contacts, one normally opened and the other normally closed. As the correct water level is reached, the switch opens one set of contacts, de-energizing the water fill valve. The other set of contacts closes and completes a circuit to the timer, allowing the timer to operate and start the next cycle. The timer will not operate during the fill cycle.
Safety Switches. - Most washers have at least two safety switches. One is an off-balance switchthat opens a circuit to the motor if the clothes shift to one side. Moving the tub to the center and rearranging the clothes will close the switch, allowing the washer to operate. This switch prevents damage to the machine from the vibration of operating with an unbalanced load The other safety switch is located near the door of the machine. Opening the door will stop the machine from operating. Some machines do not have this switch but have a locking solenoid. When the machine goes into the spin cycle, the solenoid latches the door to keep it from being opened during the spin cycle.Continue Reading