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How do you take high voltage test for LV winding of transformer?
Wiki User
∙ 12y ago
H.V.test carried out by Keeping L.V.side short cktd. & supply will be provide to h.V. side
Wiki User
∙ 12y ago
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Conversion of 2-winding transformer into auto transformer?
Yes, you can use a mutual (2-winding) transformer as an autotransformer, by connecting the two windings in series. For example, if you have a 240:120 V transformer, connecting the two windings in series and supplying the 240-V winding with 240 V can give you a secondary voltage of 360 V. But you must take into account the polarity of the transformer, and realise its capacity will change.
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.
How do you know if a transformer is a step up transformer?
You will most likely see a 'step-up' transformer on neon signs. The next time you're at a restaurant or bar, look at their neon sign. You'll see a black box (4" x 4" x 6"w) connected to the sign (usually). This is the transformer, and it takes 120 volts AC and steps it up to 7500 to 10,000 volts AC. This excites the neon gas and causes it to glow.AnswerA step-up transformer transforms voltage to a higher level. Like 120 volts to 277 volts.AnswerIt is type of transformer which is used to step up the voltage from low to high value in order to make it applicable for high rated appliances.Not only for high rated appliances but also for transmission in power distribution systems. It is critical in this role. Power distribution systems depend heavily on step-up transformers to generate the high voltages needed for more efficient long-distance power distribution. (And yes, there are step-down transformers at the other end to make the voltages more "user friendly" and less dangerous.)
What do you mean by no load of transformer?
Transformers voltage ratings are typically at full load. For instance, A 24 VAC, 10A transformer will have a terminal voltage of 24 when it is feeding 10 amps to a load. Since the transformer windings have some resistance, the transformer designer has to wind the transformer to put out more than 24 volts, since some of the voltage will be lost, dropped across the resistance of the secondary windings. But, according to Ohm's law, the voltage dropped across a resistance is proportional to the current (E=IR). If we take away the 10A load, there is no current, and therefore no winding voltage drop! The excess voltage the designer built in now appears at the terminals. This is the no-load voltage. In my example above, when we remove the 10A load, the output voltage of the transformer might rise to 26.4V. We would say the no-load voltage of that transformer is 26.4V The ratio of full-load voltage to no-load voltage is called the transformer's "regulation factor". It is calculated as: (no-load voltage - full-load voltage) / full-load voltage * 100. Ours is: ((26.4 - 24) / 24) * 100 = 10%.
How do you test a dimmer switch with a multimeter?
You cannot use an ordinary multimeter to assess the difference between a normal power transformer winding and a shorted power transformer winding. You need a Q meter and/or to power it up at a reduced voltage with limited current to see what happens. Note that a shorted power transformer is capable of exploding, so you need to take appropriate safety precautions.
How to calculate short circuit protection for transformer?
don't overload it, have a look on the transformer their should be an input voltage and an output voltage if take fails just try and see if u can overload it when you do try and figure out the voltage and get a new transformer;)!!!!!
What multimeter readings set to measure resistance indicate an open circuit and short circuit in the primary and secondary windings of a mains power transformer. And what readings show good?
You cannot use an ordinary multimeter to assess the difference between a normal power transformer winding and a shorted power transformer winding. You need a Q meter and/or to power it up at a reduced voltage with limited current to see what happens. Note that a shorted power transformer is capable of exploding, so you need to take appropriate safety precautions.
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 the impedance of a transformer?
Impedance (Z) voltage is the amount of voltage applied to the primary side to produce full load current in the secondary side. It is usually listed on the transformer nameplate, expressed as a percent, and measured by conducting a short circuit test.
What is used to control voltage at a substation?
It is carried out by tap-changing on the HV side of the transformer. The number of turns on the winding is increased or decreased by a number of turns to make the secoondary voltage take the right value. Tap-changing is done on the HV side because each turn is a smaller percentage of the voltage, which permits finer adjustment.
What is bus potential transformer in electrical?
Potential transformers are instrument transformers. They have a large number of primary turns and a few number of secondary turns. It is used to control the large value of voltage.WORKING:The potential transformer works along the same principle of other transformers. It converts voltages from high to low. It will take the thousands of volts behind power transmission systems and step the voltage down to something that meters can handle. These transformers work for single and three phase systems, and are attached at a point where it is convenient to measure the voltage.
How does a transformation feel?
A transformer works on the principle of electromagnetic induction. Let's do a bit of review and then pull some things together. Any conductor through which current is flowing will have a magnetic field around it. When the current begins to flow, the field will build. Conductors with a changing current in them, with an alternating current (AC) flowing through them, will have a changing magnetic field around them. The field will arise and take form, then collapse. It will then arise again with the opposite polarity, and then collapse. This alternating field, which is a direct result of the alternating current, can be set up near another conductor to induce a voltage in that other conductor. The magnetic field around the first conductor is said to "sweep" the second conductor and induce that voltage in it. This is electromagnetic induction, and is the principle on which transformer action occurs. If we wind a coil of wire around a ferromagnetic core, the core will facilitate the "flow" of the magnetic field that arises as AC is applied to the winding. The addition of a second (secondary) winding around the core in the vicinity of the first (primary) winding will allow an optimum amount of "sweeping action" (magnetic coupling) to occur between the two windings. And if we tinker a bit with the number of turns in the windings, we can get stepped up or stepped down voltages as a result of the transformer action in the device.Transformer is a type of machine which is used to step up or step down the voltage.and works on the principle of mutual induction.according to which voltage can be induced in a winding that is electrically isolated from the winding connected with source...
