test code for step-voltage regulators. IEC , Insulated bushings for alternating voltages above 1 V. IEC , Tap-changers – Part 2. This part of IEC is intended to assist in the selection of tap-changers designed in accordance with IEC or IEEE Std. C for use in. Tap-changers –. Part 2: Application guide. Reference number. IEC (E). This is a free 6 page sample. Access the full version online.
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International Classification for Standards ICS is an international classification system for technical standards. Please help to improve this article by introducing more precise citations. For example, in power distribution networks, a large step-down transformer may have an off-load tap changer on the primary winding and an on load automatic tap changer on the secondary winding or windings.
Thyristor-assisted tap changers use thyristors to take the on load current while the main contacts change over from one tap to the next. This technique overcomes the problems with open or short circuit taps. It is important to us that you purchase the right document. The low voltage tap may be requested to change positions multiple times each day, without interrupting the power delivery, to follow loading conditions on the low-voltage secondary 660214-2 network. However, a transformer may include a tap changer on each winding if iwc are advantages to do so.
The result operates like a dual-clutch transmissionwith the tap selector switches taking the place of the gearbox and the diverter switch taking the place of the clutch. During a tap change operation, the potential rapidly increases between the two electrodes in the bottle, and some of the energy is dissipated in an arc discharge through the bottle instead of flashing across the diverter switch contacts. From Wikipedia, the free encyclopedia. In other projects Wikimedia Commons.
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A mechanical tap changer physically makes the new connection before releasing the old using multiple tap selector switches but avoids creating high circulating currents by using a diverter switch to temporarily place a large diverter impedance in series with the short-circuited turns. This type of transformer is frequently employed in low power, low voltage transformers in which the tap point often may take the form of a transformer connection terminal, requiring the input line to be disconnected by hand and connected to the new terminal.
This power consumption can add up to a few kilowatts which appears as heat and causes a reduction in overall efficiency of the transformer; however, it results in a more compact design that reduces the size and weight of the tap changer device. No load tap changers are also employed in high voltage distribution-type transformers in which the system 60241-2 a no load tap changer on the ic winding to accommodate transmission system variations within a narrow band around the nominal rating.
On load tap changers may be generally classified as either mechanical, electronically assisted, or fully electronic. Some arcing is unavoidable, and both the tap changer oil and the switch contacts will slowly deteriorate with use.
Standards New Zealand :: Tap-changers – Part 2: Application guide
Diverter resistor A is short-circuited; diverter B is unused. Amorphous metal transformer Austin transformer Autotransformer Buck—boost transformer Capacitor voltage transformer Distribution transformer Delta-wye transformer Energy efficient transformer Flyback transformer Grounding transformer Instrument transformer Current transformer Potential transformer Isolation transformer Linear variable differential transformer Pad-mounted transformer Parametric transformer Planar transformers Rotary transformer Rotary variable differential transformer Scott-T transformer Solid-state transformer Trigger transformer Variable-frequency transformer Zigzag transformer.
Tap changers typically use numerous tap selector switches which may not be switched under load, broken into even and odd banks, and switch between the banks with a heavy-duty diverter switch which can switch between them under load. In a typical diverter switch, powerful springs are tensioned by a low power motor motor drive unit, MDUand then rapidly released to effect the tap changing operation.
Application guide This document has been re-assessed by the committee, and judged to still be up to date. The high voltage tap is set to match long term system profile on the high voltage network typically supply voltage averages and is rarely changed. Articles lacking in-text citations from September All articles lacking in-text citations Commons category link is on Wikidata.
This prevents arcing on the main contacts and can lead to a longer service life between maintenance activities. In such systems, the tap changer will often be set just once, at the time of installation, although it may be changed later to accommodate a long-term change in the system voltage profile. Transformers with this mechanism obtain this variable turn ratio by connecting to a number of access points known as taps along either the primary or secondary winding.
This is a relatively recent development which uses thyristors both to switch the transformer winding taps and to pass the load current in the steady state.
Siemens — via http: A reactance type tap changer uses a dedicated preventive autotransformer winding to function as the diverter impedance, and a reactance type tap changer is usually designed to sustain off-tap loading indefinitely. Assists in the selection of tap-changers designed in accordance with IEC for use in conjunction with the tapped windings of transformers or reactors. Agbioeletric Balun Buchholz relay Bushing Center tap Circle diagram Condition monitoring of transformers Copper loss Dissolved gas analysis Electrical insulation paper Growler High-leg delta Induction regulator Leakage inductance Magnet wire Metadyne Open-circuit test Polarity Polychlorinated biphenyl Quadrature booster Resolver Resonant inductive coupling Severity factor Short-circuit test Stacking factor Synchro Tap changer Toroidal inductors and transformers Transformer oil Transformer oil testing Transformer utilization factor Vector group.
The tap selection on any tap changer may be made via an automatic system, as is often the case for OLTC, or a manual tap changer, which is more common for NLTC. Safety of power transformers, power supply units and similar – Particular requirements – Particular requirements for isolating transformers and power supply units incorporating isolating transformers You may be interested in this related standard Safety of transformers, reactors, power supply units and similar products for supply voltages up to 1 V — Part 2.
IEC 60214-2 Ed. 1.0 en(2004)
Also assists in understanding the various types of tap-changers and their associated equipment available. Also called On Circuit Tap Changerin applications where a supply interruption during a tap change is unacceptable, the transformer is often fitted uec a more expensive and complex on load tap changing mechanism.
The disadvantage is that all non-conducting thyristors connected to the unselected taps still dissipate power due to their leakage currents and they have limited short circuit tolerance. They are often more costly but this method is used in some modern transformers. Tap changers exist in two primary types,  no load tap changers NLTC which must be de-energized before the turn ratio is adjusted and on load tap changers OLTC which may adjust their turn ratio during operation.
Alternatively, in some systems, the process lec tap changing may be assisted by means of a rotary or slider switch. Follow these links to find other Standards similar to the one you are viewing. One possible design flag type of on load mechanical tap changer is shown to the right. Reactance-type tap changers, when operating in oil, must allow for the additional inductive transients generated by the autotransformer and commonly include a vacuum bottle contact in parallel with the diverter switch.
Views Read Edit View history. Although we endeavour to 60214- an up-to-date catalogue, on occasion we may not have the latest version of a document, including where it has not yet been provided through an international feed. It is designed to cover every economic sector and virtually every activity of the humankind where technical standards may be used. To reduce arcing at the contacts, the tap changer operates in a chamber filled with insulating transformer oilor inside a vessel filled with pressurized SF 6 gas.
In moving to tap 3, the following sequence occurs:.