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What is the use of metal oxide varistor disc in Lightning arrestor?
Wiki User
∙ 14y ago
I think your answer is given in previous question -( correct size of varistor across 24v coil)
I am just pasting the same here. . .
"When the voltage exceeds the clamping voltage of the varistor, it conducts current, preventing the voltage from reaching a dangerous level. If the elevated voltage is maintained for too long a time, the varistor will heat to a point where the metals in it melt and fuse together, causing a short. This also poses the posibility of a fire risk, as the current is now conducting heavily through the varistor. This is what often happens to a varistor in a power strip when lightening strikes nearby. It renders the power strip useless. But the connected devices are usually spared. "
Wiki User
∙ 14y ago
jec888
The varistor is equivalent to a variable resistor, which is connected in parallel in the circuit. When the circuit is in normal use, the impedance of the varistor is very high and the leakage current is very small. It can be regarded as an open circuit that has little effect on the circuit. But when a very high surge voltage comes, the resistance value of the varistor drops instantly (its resistance value can change from megohm to milliohm, so that it can flow a large current, and at the same time clamp the overvoltage. At a certain value. Since the surge withstand capability of the varistor depends on its physical size, it is possible to obtain different surge current values.
For the metal oxide semiconductor nonlinear resistor with zinc oxide as the main component, when the voltage applied to both ends of the resistor is less than the varistor voltage, the varistor is in a high resistance state.
If connected in parallel on the circuit, the valve piece is in an open circuit state. When the voltage applied across the varistor is greater than the varistor voltage, the varistor will break down, showing a low resistance value, even close to a short-circuit state. The breakdown state of the varistor can be restored. When the voltage higher than the varistor voltage is removed, it returns to the high resistance state. When the power line is struck by lightning, the high voltage of the lightning wave causes the varistor to break down, and the lightning current flows into the ground through the varistor, so that the voltage on the power line is clamped within a safe range.
----We're JYH HSU(JEC) Electronics Ltd (or Dongguan Zhixu Electronic Co., Ltd.), an electronic components manufacturer. You may Google search "JYH HSU" to find our official website.
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What is a device that is capable of absorbing large currents without damage called?
Metal oxide varistor
How do you install a metal oxide varistor?
A varistor is installed onto the "line" and "Neutral" wires of an AC power input.Added:Maybe this will help you more: cf. Related links, just below this answer page.
In the electrical circuit what does this symbol M mean?
The symbol for MOTOR is the circle with an M in it.Hoped I helped :)
What does the initials MOV stand for?
The initials or acronym MOV may stand for many things. It can mean margin of victory, manually operated valve, or multiple organ failure.
Is CaO a metal oxide or non metal oxide?
Calcium is a metal, therefore this is a metal oxide.
Is phosphoros a metal oxide or a non metal oxide?
Phosphorus is not an oxide. It is an element. It is a nonmetal.
When oxygen is bonded to a metal it forms?
The oxidation of a metal produces a metal oxide. For example, calcium + oxide -> calcium oxide
What is a metal oxide?
a metal oxide is a metal that is joined to oxygen. ex: copper oxide is copper joined to oxygen. :) :P by meeeeeeeeeeeeeeeeeeee
How do you determine correct size varistor on a 24vac coil?
is this coil a single shot solenoid or is it used as a filter i assume you want to know a good value for a varistor to stop voltage spikes from the reverse EMF which is aprox. 4X the input voltage. so i would say to use 2X-3X the input Voltage so 48 or 72 Volt MOV (Metal oxide varistor) You want the varistor to be several volts greater than the peak voltage of the signal across which it is connected. 24 volts is probably the RMS value of the coils voltage. Your varistor must be selected to be greater than the peak voltage. When the voltage exceeds the clamping voltage of the varistor, it conducts current, preventing the voltage from reaching a dangerous level. If the elevated voltage is maintained for too long a time, the varistor will heat to a point where the metals in it melt and fuse together, causing a short. This also poses the posibility of a fire risk, as the current is now conducting heavily through the varistor. This is what often happens to a varistor in a power strip when lightening strikes nearby. It renders the power strip useless. But the connected devices are usually spared.
Is lead oxide a metal?
Lead oxide is not a metal. Why?Lead is metal by itself, lead oxide is metal oxide, meaning it is a chemical compound that contains at least one atom of oxygen (thus oxide) and one other element (being a metal oxide, that one other element has to be metal, in this case lead).
Is B2O3 a metal oxide or a non oxide?
It is a meltalloid oxide.
Can you burn a metal oxide?
No. A metal oxide can be thought of as the product of burning a metal. In essence it has already burned.
