Shock washing machines

In the most frequently used type of domestic washing machine, the drum containing the washing turns in a suds container. The suds container is spring-mounted in a housing with shock absorbers connecting it to the bottom of the housing in order to attenuate vibrations (Fig. 5.55). 

Position/Displacement sensors can be used in active damping systems of industrial washing machines in order to compensate for vibrations coming from unbalanced drums /laundry. These can work much like a simple automotive shock absorber. 

Equipment failure is another cause of electrical shock. Some examples include leakage in washing machines, electrical irons, water pumps, broken energized power lines, grinding, and drilling machines. The equipment must he grounded with three wire cables. 

Kolb C, Schmieder S, Schmitt C. Inappropriate shock delivery due to interference between a washing machine and an implantable cardioverter defibrillator. J Interv Card Electrophysiol 2002 7 255-256. 

Accidents involving an electric shock are usually subdivided into two categories - direct contact and indirect contact shocks. The standards that will be considered later use this distinction. A direct contact shock occurs when conductors that are meant to be live, such as bare wires or terminals, are touched. An indirect contact shock is usually associated with touching an exposed conductive part that has become live under fault conditions an example of an exposed conductive part would be the metal casing of a washing machine. 

Under the fault condition shown, the casing of the washing machine will no longer be earthed and it will become live at the full mains potential of about 230 V. When the person depicted simultaneously touches the live casing of the heater and an earthed object, such as the water pipe shown, a hand-to-hand mains voltage shock is suffered. The flow of current in this case of the indirect contact scenario is depicted in Fig. 2.8 and the equivalent circuit is shown in Fig. 2.9. 

Figure 34.2 is a picture of our washing machine as it was originally installed. Whenever the shutoff valve on the water supply line closed, water hammer, or hydraulic shock, would shake the water piping. The momentum of the water flowing in the piping would be suddenly converted to pressure. If the end of a piping system is open (as into a sump), then the momentum of the water is converted to... 

Figure 29.2 is a picture of our washing machine as it was originally installed. Whenever the shutoff valve on the water supply line closed, water hammer, or hydraulic shock, would shake the water piping. 

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