Electric shock Touch voltage

Energize the power supply and adjust it to an output of 1 to 2 mA/gel. The voltage should be held constant at no more than 75 V. DO NOT TOUCH THE SYSTEM BECAUSE FATAL ELECTRICAL SHOCK MAY RESULT. 

Do not touch high-voltage parts such as ignition transformers and do not disassemble any units while they are powered to avoid the possibility of electrical shock. 

Electric shock is normally caused either by touching a conductive part that is normally live, or by touching an exposed conductive part made live by a fault. The touch voltage curve in Fig. 6.8 shows that a person in contact with 230 V must be released from this danger in 40 ms if harmful effects are to be avoided. Similarly, a person in contact with 400V must be released in 15 ms to avoid being harmed. 

The majority of direct and indirect contact electric shock and burn accidents occur at 230 V on distribution systems or on connected equipment. There are many instances in which high voltage overhead lines are touched, so this is a form of direct contact however, they usually result in predominantly burn injuries rather than electric shock. 

Many electric shock incidents such as those described are accompanied by minor burn injuries at the points of contact. These are frequently characterised by small blisters at the entry and exit points. More severe burn injuries arise when large currents flow through the body, such as when a high voltage conductor is touched. 

Another example is the selection and use of suitably insulated cables. Their voltage and current ratings should not be exceeded where this might cause an insulation failure and the consequential exposure of a live conductor that would produce the risk of electric shock and bum injuries to anyone who may touch it. Yet another example is high voltage switchgear, such as circuit breakers. These devices may be required to clear short circuit faults on... 

There are potential electric shock hazards at higher voltages from three-phase multi-operator welding and from the use of multiple power sources (see Figs 16.6 and 16.7). In these cases the operators should be separated so that no operator can touch two electrode holders at different voltages at the same time. 

Electrical. Any repair or modification to the electronic components associated with gauges or power supplies must be done with the same concern for electrical shock that would be used in any electronic repair. Note that ion gauges operate at a high voltage. The leads are insulated, but it is still unwise to touch them ... 

Other into the material whose shock wave velocity is to be determined. This distance limits the measuring length at vdiich the shock wave mean velocity is to be determined. The twined ends of the copper wires are placed into the holes made in the material so that the tip of the wire touches the copper foils. Since the copper wires are insulated, there is no electric contact between the wires and the foils. As the shock wave arrives, the varnish insulation of the copper wire will be destroyed, and thus the electric contact between the wire and the foil will be established. As soon as the electric contact is established, a voltage signal will be produced The signal will be recorded on the oscilloscope or will be used for the start/stop of the electronic counter counting assembly. 

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