The size and construction of the element is (empirically) determined so that the heat produced for a normal current does not cause the element to attain a high temperature. The resistance of the element generates heat due to the current flow. The fuse is arranged in series to carry all the charge passing through the protected circuit. Construction Ī fuse consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non-combustible housing. Ī fuse was patented by Thomas Edison in 1890 as part of his electric distribution system. A variety of wire or foil fusible elements were in use to protect telegraph cables and lighting installations as early as 1864. History Electrical installationsīreguet recommended the use of reduced-section conductors to protect telegraph stations from lightning strikes by melting, the smaller wires would protect apparatus and wiring inside the building. Circuit breakers can be used as an alternative to fuses, but have significantly different characteristics. When a damaged live wire makes contact with a metal case that is connected to ground, a short circuit will form and the fuse will melt.Ī fuse is an automatic means of removing power from a faulty system often abbreviated to ADS (Automatic Disconnection of Supply). Short circuits, overloading, mismatched loads, or device failure are the prime or some of the reasons for fuse operation. Wiring regulations usually define a maximum fuse current rating for particular circuits. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application. It is a sacrificial device once a fuse has operated, it is an open circuit, and must be replaced or rewired, depending on its type.įuses have been used as essential safety devices from the early days of electrical engineering. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Melting of internal conductor due to heat generated by excessive current flow Light gray polycarbonate housing with polycarbonate label overlay, UL94 V-0 rated, 35mm DIN EN 60715 rail mount, DIN 43880 form factor for enclosures with 45mm front panel cutout, occupies 6 DIN module spaces (108mm)Ĭlick here to search product certificates.A miniature time-delay 250 V fuse that will interrupt a 0.3 A current at after 100 s, or a 15 A current in 0.1 s. (2 red) Indicate Cresnet Y and Z data activity at any NET port (2 green) Indicate Cresnet power present at any NET port of each corresponding power group Note: ‘Y’, ‘Z’, and ‘G’ terminals are paralleled between power groups Power Group B Cresnet distribution ports Maximum Load: 75 Watts (3.13 Amps 24 Volts DC) Power Group A Cresnet distribution ports (6) 4-pin 3.5mm detachable terminal blocks, paralleled When installed in an enclosure utilizing 45 mm cutouts, the DIN-BLOCK's front panel stays visible while the connections are concealed. Diagnostic indicators are positioned on the center front panel. Wiring connections are made using detachable screw terminals positioned along the top and bottom, clearly accessible from the front for easy installation and servicing. The DIN-BLOCK is designed to snap onto a standard DIN rail for installation in a wall mount enclosure or mounted on a wall panel. A separate power supply may be dedicated to each group, or a single supply can be connected to both groups as needed. The Cresnet ports on the DIN-BLOCK are arranged into 2 separate power groups, providing an easy way to manage the distribution of power for a complete Cresnet network. In addition to data, Cresnet carries 24 Volts DC for powering the devices connected to it. This flexible 4-wire bus allows for combinations of homerun and daisy-chain wiring, and the DIN-BLOCK provides a simple means for connecting up to 12 separate Cresnet cables in parallel as part of any-sized network. DIN rail mounting enables modular installation alongside Crestron DIN Rail lighting and automation control modules and other third-party DIN rail mountable devices.Ĭresnet is the communications backbone for Crestron lighting modules, wall box dimmers, shade controllers, thermostats, keypads, touchpanels, and many other devices. The DIN-BLOCK is a DIN rail-mounted Cresnet distribution block designed to facilitate the termination of Cresnet wiring at a head end or distribution point.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |