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Steel-reinforced aluminium cables are used for overhead lines because aluminium is much lighter than a copper conductor, despite not being quite as good a conductor as copper. The function of the steel reinforcement is to improve the tensile strength of the conductor.
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∙ 11y ago
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∙ 11y agobecause led is off the rails
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How do you test the 11KV HT cables?
The test equipment used to test high voltage cables is a hi-pot test where a high DC voltage is a applied to the cable. This voltage can be from 150% to 200% of the working voltage of the cable.See related links below.
What are some types of low voltage cables?
Below 24 volts: low voltage cables are like other cables but without so much insulation. They are made of copper and insulated with pvc, usually only one layer. They are most commonly used in cars.
What type of device is used to convert the high voltage on a feeder line to a lower voltage that can be used on the plant floor?
To convert the high voltage on a feeder line to a lower voltage that can be used on the plant floor you use a transformer.
Why transmitting of power at high voltage is economical?
For a given load, the higher the supply voltage, the lower the resulting load current. So, using high-voltages in transmission systems (1) avoid enormous voltage drops along the line, (2) enable cables of realistic cross-sectional area and weight to be used, and (3) minimise line losses. So, high-voltage transmission requires less copper and avoid line losses -resulting in lower costs.
What are instrumentation cables?
Instrumentation cables are not generic. Instrumentation cables are wires that allow for a signal to be put into one end and give the same signal at the other end without distortion. What that means is if the instrument has a resisitive sensing element the 'instrument cable' used would have a very low resistive value and protection from enviromential influence to the cable to not change the value. Instrumentation cable may also be used for powering a device - which once again if powered via regulated voltage you'll want to make sure the voltage given at one end is the same on the other end. Instrumentation cables are also used for high frequency measurements are made. These instrument cables will have a frequency limitation typically based on the length of cable used due to its capacitance.
How do you test the 11KV HT cables?
The test equipment used to test high voltage cables is a hi-pot test where a high DC voltage is a applied to the cable. This voltage can be from 150% to 200% of the working voltage of the cable.See related links below.
What two features of a high tension cable are designed to ensure electrical safety?
High-voltage cables are usually placed high above the ground. Also, where the cables touch the posts, special insulators are used.
How do you use a meggar?
A megger is used to test the resistance of high voltage cables, insulation and motor windings. The test employs a megohm meter.
Does AC have to be converted to DC in order to bury high voltage power lines?
No, there are many instances where AC high voltage lines are installed underground. Where an industrial building has an electrical vault within the building, the high voltage is brought to it using high voltage cables in conduit to supply the vault with primary voltage. These types of installations are usually only used where the customer uses a high volume of electrical power.
What is the most voltage ever insulated?
Usually high voltage is considered anything over 1,000 volts. However, in 1897 the Niagara Falls Project used rubber insulated cables for 11,000 volt circuits.
What are or relay circuits used for?
A relay is used to switch a different voltage and/or current, to the control signal.Examples:1) Low voltage electronic signals operate a relay, which can then control mains voltages and high currents. This isolates potential harmful voltages from getting into the low voltage electronics.2) The control switch may be some distance from a high power unit. Instead of running large cables and using large clumsy switches to control it, small low voltage, low current cables, can be used instead. Using a relay close to the unit to keep the price down and danger away from the operator.3) The starter motor on a vehicle, uses massive amounts of current and have thick cables to supply it. These large cables are not routed through to the ignition switch. Instead, small cables are used at low current, to operate a solenoid right at the motor. This is a relay.
What two metals are commonly used in their purest form?
Copper (electrical wiring and hot water pipes) and aluminum (high voltage cables and soda drink cans).
What is a high pot voltage test?
'High-pot' is short for 'high potential', and it is also the trade name of a high-voltage test set used for testing the integrity of the insulation of high-voltage cables and other equipment prior to putting them into service, or following maintenance.
How can graphite be used?
Graphite has many applications. Powdered graphite is used to reduce friction between machine parts, engine casings on aerospace vehicles, and shielding high voltage power cables.
Why is high voltage transmitted using bare conductors?
Because, at that voltage, the insulation does not provide any electrical isolation anyway.AnswerAs air is being used to insulate the conductors, there's little point in providing additional insulation around the conductors which would only add extra weight and expense. Of course, insulators -in the form of glass or ceramic dishes or posts- are used provide insulation from the metal towers or wooden poles, as well as the means by which the conductors are suspended or supported.Underground high-voltage cables are insulated which, together with the cost of providing the trench to house them and (in the case of very high voltage cables) their gas or oil cooling systems, is the reason why putting high voltage cables underground is so expensive compared with overhead. It has been estimated that the cost of undergrounding the UK's 400-kV system would, per kilometre, be equivalent to that of constructing a motorway.
What are some types of low voltage cables?
Below 24 volts: low voltage cables are like other cables but without so much insulation. They are made of copper and insulated with pvc, usually only one layer. They are most commonly used in cars.
Will High Definition Cables produce a much sharper picture compared with basic cables?
High Definition Cables will produce higher quality video and sound when used.
