Basic protection is defined as: Protection against electric shock under. fault-free conditions. Basic protection is provided to protect. persons or livestock coming into direct.
How can basic protection be achieved?
Basic protection is required to prevent contact with live parts and is generally verified by inspection. In domestic premises, contact with live parts may occur as a result of damage to cable insulation or enclosures or because barriers are missing.
What is a method of fault protection?
Fault protection can be achieved by automatic disconnection of the supply if the exposed-conductive-parts of equipment are properly earthed.
What are the requirements for fault protection?
Methods of Fault Protection
- Earthing of circuits and equipment.
- Protective equipotential bonding.
- Automatic disconnection.
What is the most common form of fault protection?
The requirements for protective earthing, protective equipotential bonding and automatic disconnection in case of fault should be satisﬁed. For domestic premises, earth fault loop impedance testing is the most common method used to verify circuit disconnection.
How can you protect against electrocution by direct contact?
A residual current device (RCD) can provide additional protection against direct contact. RCDs compare the sizes of the currents flowing in the live and neutral conductors of a circuit. In a healthy circuit, the currents will be equal.
Is SELV basic or fault protection?
The Separated Extra Low Voltage (SELV) systems can be thought of as having a protective partition from the other higher voltage systems. Combining the low voltage, basic insulation, and protective separation makes SELV systems one of the safest electrical systems.
What is an example of a fault devices?
For example, a short circuit is a fault in which a Live wire touches a Neutral or Earth wire. An open-circuit fault occurs if a circuit is interrupted by cut on any of wires (Phase or Neutral) or blown Fuse. … In a “ground fault” or “earth fault”, current flows into the earth.
What is voltage drop formula?
Voltage drop of the circuit conductors can be determined by multiplying the current of the circuit by the total resistance of the circuit conductors: VD = I x R.
What is overload protection?
Overload relays protect the motor, motor branch circuit, and motor branch circuit components from excessive heat from the overload condition. Overload relays are part of the motor starter (assembly of contactor plus overload relay). They protect the motor by monitoring the current flowing in the circuit.