This document provides summaries of common electrical components and concepts. It defines a fuse, circuit breaker, relay, and contactor. It also describes suppression diodes, wiring standards including American wire gauge and three-phase power, current transformers, phase monitoring relays, ground fault interrupters, emergency off switches, cable basics, heat shrink tubing, busbars, and the Restriction of Hazardous Substances Directive.

1. Electrical basics

3. A circuit breaker

4. A relay

5. A contactor

6. Suppression Diodes:

7. Wiring

8. American wire gauge (AWG)

9. Current transformer

10. Phase monitoring relay

11. Ground fault interrupter (GFI)

12. Emergency off (EMO) Switch

13. Cable Basics

14. Heat Shrink tubing

15. Busbar

17. In - rated current of a circuit breaker for low voltage distribution applications as the current that the breaker is designed to carry continuously (at an ambient air temperature of 30 °C).

20. A relay is used to isolate one electrical circuit from another. It allows a low current control circuit to make or break an electrically isolated high current circuit path.

21. A relay will switch one or more poles, each of whose contacts can be thrown by energizing the coil in one of two ways:

22. Normally-open (NO) contacts connect the circuit when the relay is activated; the circuit is disconnected when the relay is inactive.

25. A type of relay that can handle the high power required to directly control an electric motor is called a contactor.

27. Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices. Relays tend to be of lower capacity and are usually designed for both normally closed and normally open applications. Devices switching more than 15 amperes or in circuits rated more than a few kilowatts are usually called contactors. Apart from optional auxiliary low current contacts, contactors are almost exclusively fitted with normally open contacts. Unlike relays, contactors are designed with features to control and suppress the arc produced when interrupting heavy motor currents

31. A current transformer also isolates the measuring instruments from what may be very high voltage in the monitored circuit. Current transformers are commonly used in metering and protective relays in the electrical power industry.

35. GFIs are designed to prevent electrocution by detecting the leakage current, which can be far smaller (typically 5–30 milli amperes) than the currents needed to operate conventional circuit breakers or fuses (several amperes). GFIs are intended to operate within 25-40 milliseconds, before electric shock can drive the heart into ventricular fibrillation, the most common cause of death through electric shock.

38. Conductor is a material which contains movable electric charges.

39. Of the metals commonly used for conductors, copper has a high conductivity. Silver is more conductive, but due to cost it is not practical in most cases. Aluminium has been used as a conductor in housing applications for cost reasons.

41. The jacket physically protects the internal components of a cable, improves the cable’s appearance and provides flame retardancy.

42. –Protects from the environment

43. –Protects from the rigors of installation

44. Drain Wire Metallic conductor frequently used in contact with foil-type signal-cable shielding to provide a low-resistance ground return at any point along the shield.

46. Braid

47. French braid™

48. Spiral (serve)

51. Heat-shrink tubing is manufactured from a thermoplastic material such as polyolefin, fluoropolymer (such as FEP, PTFE or Kynar), PVC, neoprene, silicone elastomer or Viton.

54. Mercury (Hg)

55. Cadmium (Cd)

56. Hexavalent chromium (Cr6+)

57. Polybrominated biphenyls (PBB)

58. Polybrominated diphenyl ether (PBDE) The maximum permitted concentrations are 0.1% or 1000 ppm (except for cadmium, which is limited to 0.01% or 100 ppm) by weight of homogeneous material.