ELECTRICAL GROUNDING
We can assure electrical safety by grounding, electrical grounding is really useful because it provides “reference voltage level” it is called zero potential or ground potential and all the other voltage in the system is measured against it
- By proper grounding we can reduce the susceptibility of the equipment to interference
- Equipment damage due to lightning can be prevented
- Electrostatic buildup can be eliminated which does the component damage
- Safety of the people who service and repair electrical and electronic system
- It removes any unwanted buildup of electrical charge
If we touch a defective appliance it does the completion of a circuit to the ground so in order to avoid that grounding the case with a three wire plug will protect us by completing the circuit and blowing the fuse
HOW CAN WE ACHIEVE ELECTRICAL SAFETY
Electrical safety is mainly achieved by the help of the circuit protection devices
CIRCUIT BREAKER
Its main function is to protect the equipment, we must not reset the breaker if the line voltage is higher than 120V and reset only if you know why it is tripped
GROUND FAULT CIRCUIT INTERRUPTERS
It protects people from massive electric shocks, it detects ground faults and it reduces electrical fires
GUARDING
Guarding does the locating and enclosing of the electrical material so that people don’t accidentally come in contact with its live parts
There will be signs at the entrance of an electric room saying “danger” or “warning” and it alerts the people about the hazards
INSULATION
Insulation is to prevent the direct contact between wires, while we use certain electrical equipment we must make sure it is properly insulated
WHAT ARE CIRCUIT PROTECTION DEVICES AND WHAT DO THEY DO
In the event of ground faults, overload, or short circuit in wiring system it limits or stops the flow of current fuses and circuit breaker are the main example whenever there is a risk of a ground fault it opens the circuit and it will protect the equipment and the conductors
Arc fault device will provide protection from arc faults it will de-energize the circuit in case of arc fault
HOW CAN WE PROTECT OURSELF FROM ELECTRICAL HAZARDS
- De-energize the electrical equipment before repair
- Electric tools must be maintained properly
- Use appropriate protective equipment while working near energized line
- insulation must be checked
- make sure that the power is disconnected from the system before working
- only trained people must work on an electrical system
- we must not wear conductive material such as metal jewelry
- do not use fuses with greater capacity than the prescribed capacity of the circuit
- before working we must check circuit voltages
- do not use water to put out an electrical fire
- uninsulated conductors must be enclosed in protective areas
- in flammable liquid storage area we must only use explosion-proof devices and non-sparking switches
PROTECTION AGAINST METAL PARTS THAT BECOME ENERGIZED
In this case the best way of protection is to establish a low resistive path from the metallic case of the device to the ground, it requires a low resistance wire which will direct unwanted current to the ground and a properly installed grounding conductor which has low resistance to ground and it must greatly reduce the amount of current that passes through the body