Search results
Results from the WOW.Com Content Network
The main distribution board in an installation will also normally provide a main switch (known as an incomer) which switches the phase and neutral lines for the whole supply. (n.b., an incomer may be referred to, or sold as, an isolator, but this is problematic, as it will not necessarily be used as an isolator in the strict sense.)
In the US, where split-phase supplies are common, in a branch circuit with more than one live conductor, each live conductor must be protected by a breaker pole. To ensure that all live conductors are interrupted when any pole trips, a common-trip set of breakers must be used. These may either contain two or three tripping mechanisms within one ...
The achievement around 1983 of the first single-break 245 kV and the corresponding 420 kV to 550 kV and 800 kV, with respectively 2, 3, and 4 chambers per pole, led to the dominance of SF 6 circuit breakers in the complete range of high voltages. Several characteristics of SF 6 circuit breakers can explain their success:
Linemen from Huntsville Utilities replace a blown cutout fuse with a non-conductive extending pole tool on July 10th, 2022 in Huntsville, Alabama. Each fuse holder typically has an attached pull ring that can be engaged by a hook at the end of a fiberglass hot stick operated by a lineworker standing on the ground or from a bucket truck , to ...
Everlight EL817 phototransistor opto-isolator in DIP-4 package Halo TG110-S050N2RL 10/100BASE-TX Ethernet pulse transformer in SO-16 package, with the underside shown on the right. Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no direct conduction path is permitted.
Safety regulations of the utility must prevent any attempt to open the disconnector while it supplies a circuit. Standards in some countries for safety may require either local motor isolators or lockable handles (which can be padlocked). IEC standard 62271-102 defines the functionality and features of a disconnector.
A switchgear may be a simple open-air isolator switch or it may be insulated by some other substance. An effective although more costly form of switchgear is the gas-insulated switchgear (GIS), where the conductors and contacts are insulated by pressurized sulfur hexafluoride gas (SF 6). Other common types are oil or vacuum insulated switchgear.
A typical strain insulator is a piece of glass, porcelain, or fiberglass that is shaped to accommodate two cables or a cable shoe and the supporting hardware on the support structure (hook eye, or eyelet on a steel pole/tower). The shape of the insulator maximizes the distance between the cables while also maximizing the load-bearing transfer ...