3. Introduction of Electrical protective devices (1).pptx

this presentation is about the electrical protective devices.

1. MANOLO FORTICH TECHNICAL SKILLS DEVELOPMENT CENTER

2. Electrical protective devices

3. Protective devices Design for SAFETY Design to automatically limit or shut off the flow of electricity in the event of ground – fault ,overload or a short circuit in the wiring system

4. fuses An overcurrent device that is place in the circuit to protect the circuit from excessive spikes in current They automatically open or break the current path when the amount of current becomes excessive. Can be fix in replacing with a new fuse Use the size and type of fuse that is recommended by the manufacturer Never use anything other than fuse to complete a circuit (wire, foil, solder) Replace with the correct voltage rating or higher

5. Circuit breaker An over – current devices that is placed in circuit to protect the circuit from excessive spikes in current They automatically open or break the current path when the amount of current becomes excessive They ca be fixed by resetting the circuit breaker

6. Classification of circuit breaker Plug-in Type Circuit Breaker PANEL BOARD

7. Bolt-on type Circuit Breaker

8. Ground fault circuit interrupter ( gfci ) The GFCI is designed to shut off electrical power in as little 1 or 4oth of a second 6 milliamperes (mA) trip off enough to prevent electrocution The GFCI is often found in wet locations such as bathrooms or kitchens The GFCI can be fixed by resetting the GFCI

9. GfCI OPERATING PRINCIPLE

10. Surge protectors/suppressors Also called surge arrestors Limits surge voltages (spikes) to prevent damage to equipment power supplies

11. Surge protector operating principle

12. Lightning arrester is a device used on electric power transmission and  telecommunication   systems to protect the insulation and conductors  of the system from the damaging effects of  lightning

13. Lightning arrester operating principle

14. Wire sizing Two methods or standards for wire sizing Based on the diameter or size of the wire AWG American Wire Gauge (AWG) Ranges is from #40, the smallest, to #4 or #0 the largest

15. grounding Systems of conductors that provide a current path from electrical circuits or equipment to earth Purpose: To protect the operator and patient from electric shock

16. Grounding conductor Green wire or green with one or more yellow stripes Not used as normal carrying wire Fault condition current carrying wire only characteristics Must be a solid wire

17. How to wire/terminate circuit breaker and ground fault circuit interrupter ( gfci ) Determining where to install the Circuit Breaker T urn off power supply to the electrical panel

18. Inspect the circuit breaker arrangement for unused locations Look for a blank area on the electrical panel that can accommodate a circuit breaker.

19. 3. Remove the electrical panel cover Use a screwdriver to remove 3 of the screws supporting the cover

20. 4. Test the panel to make sure the power is off. Use a test light or meter set to check for the presence of power

21. 5. Find the unused space next to or between existing circuit breaker The new circuit breaker you install will need to be placed next to a circuit breaker already in place

22. 6. Placing circuit breaker in the panel Make sure you have a correct circuit breaker

23. 7. Set circuit breaker handle in OFF position The circuit breaker has 3 possible positions: ON and OFF and a mid position when TRIPPED

24. 8. Align the circuit breaker with the bars in the panel Tilt the circuit breaker so that the hold-on clip on the bottom of the circuit breaker is attached to the plastic.

25. 9. Firmly press on the circuit breaker to seat it onto the bus bar. Use you thumb to press firmly but gently on the circuit breaker until it snaps into place on the bus bar

26. 10. Connect the circuit wiring to the electrical panel. After making sure the circuit breaker is still the OFF position, connect the white neutral wire and the black hot wire to the breaker.

27. 11. Remove knockout plates from your cover as needed . Bring the cover up to the panel to compare the new circuit breaker location to the cover openings.

28. 12. Clean all the foreign objects out of the panel and reinstall the cover. Remove any tools, wire scraps or other foreign objects that could cause a short circuit from the interior of the panel.

29. 13. Turn on the main breaker and test your new circuit breaker. Standing to the side of the panel, restore power to the panel by setting the Service Disconnect or Main to “On”.

30. 14. Label the circuit breaker. Locate the panel’s circuit directory on the inside of the panel door.

31. Gfci termination procedure Turn Off power at the Main circuit Locate the circuit breaker or fuse that controls the outlet you plan to replace and shut off the power to the circuit.

32. Stripe the Wires. Strip the insulation from the wires to the expose the amount of wire shown on the stripping gauge located on the back of GFCI plug receptacle .

33. 3. Connect the outlet. Remove the tape covering the “load” terminals and connect the wires leading to another outlet or outlets to these terminals. Fold the wires back into the box and screw on the GFCI receptacle and cover plate.

34. 4. Label the Outlet. Attached the “GFCI – protected outlet "label to downstream outlet. Test the downstream outlet by plugging the GFCI tester and pressing the test button. Press the reset button on the GFCI to re-energize the outlet.

35. GROUP ACTIVITY Terminate/connect the GFCI and breaker in the Power Panel in the lay-out provided below PP GFCI LEGEND: PP – POWER PANEL GFCI – GROUND FAULT CIRCUIT INTERRUPTER JB – JUNCTION BOX UB – UTILITY BOX - EMT/IMC PIPE

36. THE END