1. Ground fault interrupter Mohammed hussein al issawi 2080013

2. What is a ground fault interrupter Ground fault interrupters are designed to protect us from electrical shock by interrupting a household circuit when there is a difference in the currents in the "hot" and neutral wires. Such a difference indicates that an abnormal diversion of current from the "hot" wire is occuring. Such a current might be flowing in the ground wire."hot" and neutral wiresground wire

3. How does it work In a 120 volts outlet in the United States, there are two vertical slots and then a round hole centered below them. The left slot is called "neutral," the right slot is called "hot" and the hole below them is called "ground."The GFI has a "Test" button which causes a small difference between "hot" and neutral currents to test the device. There is also a reset button to use after it has been tripped.

4. GFI current flow detection If an appliance is working properly, all electricity that the appliance uses will flow from hot to neutral. The GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one- thirtieth of a second.

5. Protection failure If a ground fault receptacle were unable to provide protection when the test button is pressed, the reset button would remain recessed. With the reset button not “popping out”, it signifies that GFCI protection was no longer available.New Techniques Such as neon and LED testers are used to automatically Detect if the GFCI protection is available or not.

6. Neon tester Neon testers use “incandescent” bulb to to determine if the system is having a faulty wiring. If the wiring is correct, the bulb will light (on) if connected as following: 1. Hot and Ground, on. 2. Hot and Neutral, on. 3. Neutral and Ground, off. If hot is off and neutral is on, there is a problem the problem is fault.

7. LED tester When tested, a rapid -flashing red LED will be activated if the ability of the GFCI to provide protection is no longer present. Emits light only for a forward bias. All 3-LEDs are on when ground voltage is almost 10 V above the neutral potential. detects approximately an (8-10)V ground to neutral potential.

8. NEON VS LED The neon tester is a voltage controlled device and it needs 70V to turn the neon on and will not give a warning until the ground voltage is greater than 70. The LED is a current controlled device and tests a current cappability of (20mA to 50 mA). The neon tester does not detect polarity The LED tester only in the forward bias To minimize the risk of fire, the neutral voltage should not exceed 5% of the line voltage. This is good for LED tester, but not used for the neon tester

9. Thank you…