1 / 22

Extra-low Voltage Electrical Practice and Wiring

Extra-low Voltage Electrical Practice and Wiring. Accessories & wiring examples Written by Ray Miller. Introduction . This slide show provides an overview of some accessories used in ELV wiring as well as the application of these accessories. Content. Overview Warnings

marsha
Télécharger la présentation

Extra-low Voltage Electrical Practice and Wiring

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. Extra-low Voltage Electrical Practice and Wiring Accessories & wiring examples Written by Ray Miller © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  2. Introduction This slide show provides an overview of some accessories used in ELV wiring as well as the application of these accessories. © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  3. Content • Overview • Warnings • Wiring protection fuses and circuit breakers • Current measurement • Circuit control and voltage regulation • Examples of wiring practices © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  4. Overview • Components and ELV accessories should be: • SAFE • Used correctly as per Aust. Standards and manufacturers’ recommendations • Rated to suit the application under worst case conditions • Be reliable for the life of the energy system • Be designed to work in with other components © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  5. Vocabulary • ELV = Extra-low voltage as defined in Australian Standards © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  6. Accessories • ELV surface mounted power socket • Rating 15 A but only used to a maximum of 10 A continuous • Labelling System voltage and rated current eg 48 V 10 A © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  7. Warning:not to be used for ELV! • Three pin 240 V a.c. (LV) accessories (eg plugs and sockets etc) are not to be used for wiring ELV © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  8. Wiring Protection (fuse switch) • Wiring protected by fuses combined with switch function • Example of a combined set of 3 fuses formed into a switch assembly • Used for battery isolation Open Closed © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  9. HRC fuse for fuse switch • Typical fuse fitted to a fuse switch • Type HRC fuses • Rating 160 A continuous © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  10. Wiring Protection (fuse switch) • 25 A fuse switch • Holds 3 fuses or separate circuits • Suitable for SELV circuits • Clear labelling © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  11. Wiring protection: Circuit breaker d.c.operation • Similar characteristics to HRC fuse • Short circuit and over current protection • Din rail mounting • Can be Reset • Dual use as a switch and wiring protection • Thermal (long-term) and magnetic (short term) operation © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  12. Wiring protection:Circuit breaker d.c. thermal • Thermal circuit breaker • Wiring is only partly protected, for long- term over-current • Very slow to respond to large high current overloads © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  13. Wiring protection:Circuit breaker d.c. • Auxiliary set of low current contacts fitted • The change-over contacts can be used as a remote indication of the circuit breaker state Auxiliary contacts Main connections © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  14. Switch used for lighting • LV switch used for ELV d.c. • Rated 10 A 240 V a.c. • Presses into switch plate • Has loop terminal • Change-over option • X terminal connected to supply is centre of change-over • Terminal 1 normally connected to load/light © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  15. Measurement, amp meter • Analogue amp meter • Integrated 50 A current shunt • Powered by current through shunt • Simple and long-life solution for current monitoring © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  16. Current Shunt • A very low value but known resistor • Used for measuring circuit current • Calibrated in mV per per amperes eg 50mV 500A • Mounting bolts for cable lugs © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  17. Circuit control using relays • Relays can prove circuit isolation • Control of high currents using a low current circuit • Low resistance low loss & multiple contacts • Catch diode should be fitted across relay coil to prevent coil back e.m.f. from causing damage and interference to other circuits and equipment Two relays shown © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  18. Regular used for Wind & PV • Battery voltage/ charge regulator • System voltages 12-48V • Charge Currents to 20 A • Load currents to 20 A • Measures current and voltage and logs AH for 30 days • Has some control functions eg low volts cut-out, boost charge, generator start etc. © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  19. PV panel connection box • Blocking diode fitted • Wiring protected by conduit • Small amount of wiring slack for ease of termination and removal • Clear PV module instructions • Weather seal fitted conduit Blocking diode © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  20. PV array wiring (large) • Array wiring is protected by fuses • Each string is wired back to this panel • Array broken up into sub-arrays • Commoning terminal strips are used © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  21. Battery terminals • Should be bolted • Use stainless steel bolts, nuts and washers • Use crimp lugs • Have insulating covers (removed in photo) © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

  22. Earth cables • Should be green/yellow stripe • Multi-stranded cable • Building cable earth should be secured under two screws © 2002, 2003 TAFE Qld Renewable Energy Centre BNPIT

More Related