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What else can I help you with?
What is the voltage output if the transformer is connected backwards?
It doesn't really matter which way around you use a transformer, the primary winding is ALWAYS whichever winding you connect to the supply, and the secondary winding is ALWAYS whichever winding you connect to the load. For either connection, the turns ratio will ALWAYS equal the voltage ratio for an ideal transformer (or close enough for a real transformer).
What will happen to the transformer if DC voltage is applied to the primary winding?
DC current will not pass through a transformer, in the sense that a DC current on the primary will not produce a DC output from the secondary. A constant DC current will not produce any output from the secondary but there may be transient effects as the DC current is connected or disconnected (in which case, it's really an AC current, isn't it?) More about this below because I don't think that's really the question. If you pass DC current through either winding of a transformer, two things will happen. First, you will heat up the transformer and, if you have enough DC current, you will burn it out. Second, you will induce a magnetic field in the core. The more current, the closer the core gets to "saturation" or the maximum field it can support. This is important if there is both DC and AC current present because the more DC field in the core, the less core capacity is available to "transform" AC current. As the core operates closer to saturation, the AC waveform will be distorted and some of the AC power will be lost to heating the transformer. For example, if the primary of a transformer is connected to an AC source, and a DC source is connected to the secondary, then the primary current drawn by the transformer will increase, possibly enough to destroy the transformer. There are special transformers, called magnetic amplifiers, which take advantage of this effect to use a DC current to modulate an AC current. There are transient effects of DC currents in a transformer winding. As the DC current magnetizes the core, energy is stored. When the DC current is disconnected, this stored energy wants to leave the core. It can do this by inducing a voltage in either of the windings. If both windings are open circuit, this voltage can be very high. So you may see a spark jump when the DC voltage is disconnected. In a large transformer, this discharge may break down the transformer insulation and damage it. Some switching power supplies take advantage of this effect in which case the transformer is wound slightly differently and called a "coupled inductor."
What is a current transformer and how can a current transformer be used to extend the range of a wattmeter?
A current transformer (CT) works just like any other transformer. It is important to note it is not referenced to ground. It reflects current flow, not phase to ground voltage, so it attempts to hold current constant, not voltage. There is usually one primary "winding": one large cable through a donut CT, and multiple secondary windings. If a secondary winding is shorted (a wire placed across its terminals), the voltage built up in the secondary will be equivalent to V = I*Z, where I is the secondary current, and Z is the impedance of the secondary winding, usually specified as some flat value plus so many ohms per winding. If too big of an impedance is placed on the secondary, a voltage will build up to the point that the donut CT saturates, resulting in an output wave that has a large amount of harmonics. If the CT is open circuit\'d, voltage will build up until it is high enough to arc over (usually where it should have been shorted). CT\'s can be damaged by open circuiting them, so don\'t do it.
Can a high voltage transformer be megged with a megger meter?
No. A megger's output voltage is not high enough to test the insulation of a high-voltage transformer if, by 'high-voltage transformer ', you mean a distribution transformer or power transformer. Instead, a high-voltage test set or 'pressure tester' (e.g. a 'HiPot' tester) must be used, as these produce far higher voltages.
What is hold in winding?
Hold in winding refers to the specific winding configuration in an electromagnetic device, such as a relay or solenoid, that maintains the position of the armature or movable part when the device is energized. This winding generates a magnetic field that keeps the armature in place, preventing it from returning to its default position until the power is removed. The design ensures that the electromagnetic force is strong enough to hold the armature securely during operation.
What is the voltage output if the transformer is connected backwards?
It doesn't really matter which way around you use a transformer, the primary winding is ALWAYS whichever winding you connect to the supply, and the secondary winding is ALWAYS whichever winding you connect to the load. For either connection, the turns ratio will ALWAYS equal the voltage ratio for an ideal transformer (or close enough for a real transformer).
Why the winding resistance of transformer is not sufficent when it is used in dc supply?
It is.AnswerA transformer is designed to operate with an AC supply voltage, not DC -in fact, it cannot operate with a DC supply voltage.Opposition to the flow of alternating current is made up of resistance and reactance. Resistance depends upon the length, cross-sectional area, and resistivity of the transformer winding conductor. Reactance depends upon the inductance of the transformer winding and the frequency of the supply voltage.Because a transformer winding is highly inductive, its reactance is very much larger than its resistance, and is more than sufficient to limit the AC current to a value that will not overheat the winding conductor. However, if you supply the transformer with a DC voltage that is equivalent in value to its AC rated voltage, the low value of resistance will allow a very large DC current to flow -large enough, probably, to overheat the conductor insulation, possibly causing it to break down and cause severe damage to the transformer.
When dc voltage is supplied to the primary coil of the transformer then the voltage be induced in secondary or not?
The windings of a transformer have both resistance and inductance. When you apply an AC voltage to the primary winding, the opposition to current flow is a combination of resistance and inductive reactance; although the resistance of the winding is relatively low, its inductive reactance is high. The resulting impedance (the vector sum of resistance and inductive reactance) will, therefore, be high and the resulting current will be low.If, on the other hand, you applied a DC voltage to the winding, the only opposition will be the low resistance of the winding. So, if the value of DC voltage is roughly the same as the rated AC voltage, a large value of current would result -high enough to probably burn out the winding.Since transformers work on the principle of mutual induction, a fluctuating magnetic field is necessary to induce a voltage into the secondary winding. Since a fluctuating magnetic field requires a fluctuating current, a transformer will only work if an AC voltage is applied to its primary winding.So, not only will a transformer not work when a DC voltage is applied to its primary winding, it will probably burn out the primary winding.
What happen if primary of transformer connected to dc?
Nothing noticeable. DC power is not transmitted between the coils of a transformer. There would be no current on the other side of the transformer, unless the power of the source was constantly modulated. bescause flux does not change its state.after some time excessive heat is produced and winding may burnAnswerA transformer's primary winding presents two forms of opposition to current flow. The first is resistance, which is dependent upon the length, cross-sectional area, and resistivity of the wound conductor. The second is reactance, which depends upon the inductance of the winding and the frequency of the supply. Resistance opposes both AC and DC currents, while reactance opposes only AC current. In the case of a transformer's windings, the resistance is relatively low while the reactance is very high. When an AC voltage is applied, the reactance is sufficiently high to limit the value of AC current flowing through the winding. However, the resistance is so low that a large current would flow if an equivalent DC voltage was applied instead. This current would likely overheat the winding's insulation, resulting in its breakdown, causing a short circuit(s) which could severely damage the transformer.
What will happen to the transformer if DC voltage is applied to the primary winding?
DC current will not pass through a transformer, in the sense that a DC current on the primary will not produce a DC output from the secondary. A constant DC current will not produce any output from the secondary but there may be transient effects as the DC current is connected or disconnected (in which case, it's really an AC current, isn't it?) More about this below because I don't think that's really the question. If you pass DC current through either winding of a transformer, two things will happen. First, you will heat up the transformer and, if you have enough DC current, you will burn it out. Second, you will induce a magnetic field in the core. The more current, the closer the core gets to "saturation" or the maximum field it can support. This is important if there is both DC and AC current present because the more DC field in the core, the less core capacity is available to "transform" AC current. As the core operates closer to saturation, the AC waveform will be distorted and some of the AC power will be lost to heating the transformer. For example, if the primary of a transformer is connected to an AC source, and a DC source is connected to the secondary, then the primary current drawn by the transformer will increase, possibly enough to destroy the transformer. There are special transformers, called magnetic amplifiers, which take advantage of this effect to use a DC current to modulate an AC current. There are transient effects of DC currents in a transformer winding. As the DC current magnetizes the core, energy is stored. When the DC current is disconnected, this stored energy wants to leave the core. It can do this by inducing a voltage in either of the windings. If both windings are open circuit, this voltage can be very high. So you may see a spark jump when the DC voltage is disconnected. In a large transformer, this discharge may break down the transformer insulation and damage it. Some switching power supplies take advantage of this effect in which case the transformer is wound slightly differently and called a "coupled inductor."
What is a current transformer and how can a current transformer be used to extend the range of a wattmeter?
A current transformer (CT) works just like any other transformer. It is important to note it is not referenced to ground. It reflects current flow, not phase to ground voltage, so it attempts to hold current constant, not voltage. There is usually one primary "winding": one large cable through a donut CT, and multiple secondary windings. If a secondary winding is shorted (a wire placed across its terminals), the voltage built up in the secondary will be equivalent to V = I*Z, where I is the secondary current, and Z is the impedance of the secondary winding, usually specified as some flat value plus so many ohms per winding. If too big of an impedance is placed on the secondary, a voltage will build up to the point that the donut CT saturates, resulting in an output wave that has a large amount of harmonics. If the CT is open circuit\'d, voltage will build up until it is high enough to arc over (usually where it should have been shorted). CT\'s can be damaged by open circuiting them, so don\'t do it.
Why dew point measurement is necessary in nitrogen filled transformer?
Short Answer: Dew point measurement is necessary to ensure the moisture content of the cellulose insulation is low enough to safely energize the transformer (after filling with oil). Maximum acceptable moisture content varies with unit size/age, but less than 1% moisture content is generally acceptable.
How many amps does a 3 kva transformer draw?
The primary current of a transformer depends upon the secondary current which, in turn, depends upon the load supplied by the transformer. There is not enough information in the question to determine the rated primary and secondary currents of the transformer.
Why were instrument of a transformer placed on a high voltage side in short circuit test?
I assume "tension" in this question should be replaced with "voltage". Short circuit tests are often performed from the lower voltage side of the transformer, since a lower voltage source is then required to perform the test. Often times the test lab may not have a source that can output a high enough voltage to perform from the high voltage winding.
Can a 1500KVA transformer feed a 1600A 480V service?
No, a 1500KVA transformer is not large enough to handle a 1600A load at 480V. The transformer should have a higher kVA rating to support the current demand of 1600A. A transformer with a minimum capacity of 1920KVA would be needed for this application.
What month is transformer 4 coming out?
June 27, 2014. That should be enough to answer your question.
Can a high voltage transformer be megged with a megger meter?
No. A megger's output voltage is not high enough to test the insulation of a high-voltage transformer if, by 'high-voltage transformer ', you mean a distribution transformer or power transformer. Instead, a high-voltage test set or 'pressure tester' (e.g. a 'HiPot' tester) must be used, as these produce far higher voltages.
