27-06-2012, 02:46 PM
earth leakage circuit breaker
ELCB project.docx (Size: 325.84 KB / Downloads: 83)
• Problem identification:
In fault finding first check in the power supply section of the ELCB.
After checking the power supply section check the inbuilt circuit of the ELCB.
Then check the circuit all component.
Then check the input connector of the ELCB.
After all component testing then check the inbuilt coil of the circuit. The coil
can be failed due to the over voltage of the power supply.
• Specification of ELCB:
Number of Pole: 2 Pole & 4 Pole.
Rated Voltage: 22V For 1 & 440V For 3.50Hz.
Earth Leakage Sensitivity: 3ma to 30ma.
Earth Leakage Tripping Time: Less than 0.03 Second
Over Voltage Cut Off: 290V, 50Hz, 5% Respect to Neutral.
Over Voltage Cut Off Time: Less Than 0.1 Second
Industrial process:
What is ELCB
The earth leakage circuit breaker or commonly called the ELCB is located inside the home electrical panel or distribution board. This component of the home electrical installation is designed to detect any leakage of electrical current.
This so-called leakage current occurs when there are some defects in the performance of some part of the installation, which can be caused by faulty components or by injuries to the insulation of the wiring, cables, electrical appliances or other accessories such as the switches and socket outlets.
When the current leakage occurs, the ELCB then trips the electricity supply within a fraction of a second of the leakage being detected, before the magnitude of the current reaches a lethal level.
Therefore any possibility of serious injuries due to electric shock to persons who are in contact with the electrical installation at that particular moment is minimized. The use of ELCB in house wiring is required by law and omitting it is a serious offence.
Component from the left, with the letters CLIPSAL on it. The left-most component is the Shown in below figure of a typical home electrical panel. The ELCB is the second main switch (in black color), while all other components on the right of the ELCB are the outgoing circuit reakers.
• Fault in ELCB:
Problem in magnet
Problem in coil
Connector fails
Inbuilt spring fail
Fault in MCB switch
Fault in power supply
Earth leakage protection
It is for protecting power distribution system, earth leakage devices are only for protecting people from electrocution. An overload circuit breaker is designed to interrupt a circuit when the current exceeds a preset limit. In a thermal type breaker, a small over-current (due to overloading) can be tolerated for a prolonged period before tripping, although a large over-current (due to a short circuit) will trip fairly quickly.
A magnetic type breaker will trip very quickly once its threshold current has been reached. As the current necessary for fatal electrocution is less than a couple of Amp. For duration of less than a couple of seconds, an overload breaker offers virtually no protection from electrocution. Earth leakage protection devices are designed to trip for fault currents between 10 ~ 100 am and for interrupt times between 40 and 100 milliseconds after a fault current is sensed.