1 / 39

“Basic” earth leakage protection training course

“Basic” earth leakage protection training course. Instructions to read carefully before starting. You are going to have a 25 minutes e-learning Please follow the below instructions : Open the module in a slide show format Read the question and click a mark on your answer

judah
Télécharger la présentation

“Basic” earth leakage protection training course

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. “Basic” earth leakage protectiontraining course

  2. Instructions to read carefully before starting You are going to have a 25 minutes e-learning Please follow the below instructions : • Open the module in a slide show format • Read the question and click a mark on your answer • You can put several marks • But you cannot remove a mark you already put in a box (it opens the next slide) • Click on the button to display the answer • Then click anywhere on the answer’s page to move on to the next slide And….enjoy your training !

  3. Training Objectives • By the end of the course: Be aware and understand current risks Know how to protect against electrocution

  4. 20 4000 100 4th 600 people die Introduction • In the UK • What is the average of people who die each year nationally due to unintentional electrocution? • In France • How many severe electric shocks still occur? • How many deaths per year due to electrocution? • In the US • What is Electrocutions rank in causes of industrial fatalities? (40% of such deceases involve children aged between 0 and 9) (roughly 3,600 disabling injuries occur every year)

  5. Understand the current risks Position earth leakage protection devices in an electrical installation Contents

  6. A child sticks his fingers in the holes ofa socket outletthere's a risk of electrocution.... Right Wrong • 1. By short-circuit. • 2. By direct contact • 3. No risk of electrocution

  7. A child sticks his fingers in the holes of a socket outlet.Can an earth leakage device protect the child from electrocution? • Yes • No

  8. A child sticks his fingers in the holes of a socket outlet.Could a circuit breaker protectthe child against electrocutionby direct contact? • Yes • No

  9. Earth leakage protection device The two conductors forming the cable. Socket outlet Light switch (open) Light (off) Case 1: In the circuit below, the switch is open: the light is off.Is there current in the installation? Right Wrong • A. Is there current in the red conductor? • B. Is there current in the blue conductor?

  10. Case 1: The switch is open, the light is off. The red conductor is damaged upstream of the switch. A person touches the cable in that location.What happens to the person? • 1. Nothing happens. • 2. He feels a shock.Current goes through his body. • 3. He feels a shock but there is no current • 4. The light goes on. Right Wrong

  11. Case 1: The switch is open, the light is off. The red conductor is damaged upstream of the switch. A person touches the cable in that location.Where is there current in the installation? • A. In the red conductor? • B. In the blue conductor? • C. In the light? YES NO

  12. Case 1: The switch is open, the light is off.A person touches the damaged red conductor. Current flows in the red conductor and in the person's body.Where does the current go next? • 1. It returns to the source via the blue conductor. • 2. It returns to the source via the red conductor. • 3. It returns to the source via the earth. • 4. It does not return to the source. Right Wrong

  13. Case 1: The switch is open, the light is off.A person touches the damaged red conductor.If the current measured in the person’s body is 100mA, what is the current in the red conductor ? • 1. Equal to 100 mA. • 2. Less than or equal to 100 mA. • 3. Greater than or equal to 100 mA. • 4. Zero. Right Wrong

  14. Case 1: The switch is open, the lamp is off.A person touches the damaged red conductor.If the current measured in the person’s body and in the red conductor is 100mA, what is the current in the earth? • 1. Equal to 100 mA. • 2. Less than or equal to 100 mA. • 3. Greater than or equal to 100 mA. • 4. Zero. Right Wrong

  15. 1 2 3 4 Case 2: In the same circuit as previously, the switch is kept closed, the light is on.Where is there current? ? Right Wrong ? • 1. In the red conductor? • 2. In the blue conductor? • 3. In the earth conductor? • 4. In the earth? ? ?

  16. Case 2: The light is on. It consumes 1.5 A. The red conductor is damaged. A person touches the cable in that location. He feels a shock.Where is there current?(click on each item in the diagram through which current flows)

  17. Case 2: The light is on. It consumes 1.5 A.A person touches the damaged red conductor.A 150 mA current goes through a part of his body.What is the current in the light, remembering that it was 1.5 A before the incident? • 1. It doesn't change • 2. It gets lower • 3. It gets higher Right Wrong ? 150 mA

  18. Case 2: The light is on. It consumes 1.5 A.A person touches the damaged red conductor.A 150 mA current goes through a part of his body.What is the level of current in the blue conductor? Right Wrong • 1. It doesn't change • 2. It gets lower • 3. It gets higher ? 1.5 A 150 mA

  19. Case 2: The light is on. A person touches the damaged red conductor. A current goes through a part of his body. What is the current in the red conductor? Right Wrong • 1.5 A • 1.65 A • 1.80 A • 3 A • 3.15 A ? 1.5 A 1.5 A 150 mA

  20. Let's summarise: Current characteristics in the case of electric shock by direct contactthe difference between currents in the blue conductor and the red conductor is always: Right Wrong • 1. greater than or equal to the current in the human body • 2. equal to the current in the human body • 3. less than or equal to the current in the human body 1.65 A 1.5 A 1.5 A 150 mA

  21. As of what level can current flowing in the human body cause injuries? Right Wrong 1A 500 mA 80 mA 40 mA 10 mA 0.5 mA heart stop heart fibrillation tissue burningsbreath paralysis muscle and lung contractionno physiological damage discomfortno actual danger Personal injuries, according to level of current.

  22. Given that a current of about 40 mA can injure tissues and organs, a device intended to protect against electrocution must trip whenever Right Wrong • 1. The current in the cable increases by 40 mA. • 2. There is a 40 mA difference between the currents in the red and blue conductors. • 3. There is an 80 mA difference between the currents in the red and blue conductors. 1.54 A 1.5 A 1.5 A 40 mA

  23. By definition, an earth leakage protection device trips if the difference in current in the two conductors is greater than its sensitivity (or pick-up level)What is the sensitivity of an earth leakage device required to protect against electrocution by direct contact? Right Wrong • 1. 30 mA • 2. 40 mA • 3. 1.5 A • 4. 1.54 A

  24. With an energised part, when does the earth leakage protection device trip? Right Wrong • 1. Before the person touches the damaged conductor. • 2. Shortly after the person touches the damaged conductor. • 3. As soon as the person touches the damaged conductor.

  25. Now, if the person is subjected to 20 mA, will the earth leakage protection device trip? • Yes • No

  26. If the light is off, will the earth leakage protection device trip to ensure the person's safety? • Yes • No

  27. Let's summarise: Earth leakage protection operationThe protection device prevents the current from rising above 30 mA? • 1. In the human body. • 2. In the socket. • 3. In the power supply cables. Right Wrong

  28. Protection against electrocution by direct contact 1. An electrical part 2. A non-electrical metal part A person touches... 1. A short-circuit 2. A failure of accessible insulant Because of... 1. Always an earth leakage protection device2. An earth leakage protection device or a circuit breaker Protection is ensured by... 1. Different from the current felt by the person 2. Equal to the current felt by the person The current detected by the earth leakage protection device is... 1. Always 30 mA 2. Variable according to the installation The sensitivity of the protection device is... 1. Following direct contact 2. Before direct contact The protection device trips…

  29. Understand the current risks Contents Position earth leakage protection devices in an electrical installation

  30. Socket-outletsChild's room in a new homeDo the socket-outlets comprise a risk... Right Wrong • 1. High • 2. Medium • 3. Low

  31. LightingPlastic ceiling fixture in the dining room of a new homeDoes this ceiling fixture comprise a risk... • 1. High • 2. Medium • 3. Low Right Wrong

  32. LightingPlastic ceiling fixture in the bathroom of a new homeDoes this ceiling fixture comprise a risk... Right Wrong • 1. High • 2. Medium • 3. Low

  33. LightingPlastic fixtures in the bathroom of a new homeHow can protection be provided... Right Wrong • 1. A 30 mA RCD • 2. A 100 mA or higher RCD • 3. Earthing + a device that trips in the event of an insulation fault

  34. Circuits to be protected against electrocution by direct contact Protection against direct contact mandatory Protection against direct contact recommended Dry environment Wall sockets Fixed lighting / insulating casing Wet environment Lighting Wall sockets Fixed devices / metal casing

  35. This device is an RCCB.Will it trip in case of ..... Right Wrong • 1. …overloads • 2. …short-circuits • 3. …earth leakage faults

  36. In this switchboard, which circuit should be equipped with earth leakage protection against direct contact? Right Wrong

  37. Where would you position this RCCB? Right Wrong • 1. In place of the circuit breaker • 2. In addition to the circuit breaker • 3. At the incoming point of the switchboard

  38. Where would you position the RCCB? Right Wrong • 1. At the incoming point of the switchboard • 2. On the socket-outlet circuits

  39. Power Business Academy Thanks! Survey Please take 5 minutes to answer this survey For further information, please contact by email: Fr-Power-Business-Training@Europe Schneider Electric - Residual Circuit Devices - 03/2012 71 71

More Related