Grounding
Electric Shock: Causes and preventative measures Dangerous voltages The following voltages can be dangerous: A.C. voltage with a peak value of 42.4 V and higher D.C. voltage of 60 V and higher.
Causes If a person touches a component that is under dangerous voltage, it can cause electric shock. This contact is divided into two categories: Type of contact
Definition
Direct contact
Contact with components that are supplied with a voltage in undisturbed operation
Indirect contact
Contact with components that are supplied with a voltage caused by a fault
Preventative measures against direct contact If components carry dangerous voltage, people must be prevented from coming into direct contact and therefore risking injury. The following measures considered: Secure separation between circuits Housing or cover Insulating active components Energy restrictions (capacitor loads, protective impedance) Voltage restriction Additional fault current protective circuits
Preventative measures for indirect contact A fault could also occur, in which case preventing people from getting an electric shock (by indirect contact) is also necessary. The following measures can be considered: Doubled/reinforced insulation Basic insulation and protective grounding Additional fault current protective circuits
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