Medium voltage instrument transformers ritz instrument. Abb reference guide oem instrument transformer reference guide 1 low voltage switchgear cts primary current window diameter in. Window type current transformer, ct transformer, mini. Current transformer ct selection guide january 18, 2017. Phoenix contact current transformer pact mcrv24012.
To check pricing and availability for a specific current transformer model, give us a call at 614 8896152 or use our quote request form. The primary winding may be a permanent part of the current transformer, i. This type of current transformer is available to measure ac currents from 100a to 600a, at 50 to 400hz. A window type current transformer is sometimes also known as a zero sequence current transformer or by the acronym, zsct.
Window or bus type split core freestanding outdoor versus indoor. We use three types of current transformers that come in all sizes. Window type cts should be mounted with the h1 side of the window towards the power source. Shop for current transformers, current transformer from platt electric supply. Instrument transformer basic technical information and. A current transformer without primary conductor and primary insulation of its own, which can be mounted over an insulated cable. I purchased this ac current transformer for a power generator wattage meter and it does a great job measuring the wattage of my generator. Current transformers cts are instrument transformers that. Cts with larger sensing windows that will easily accommodate the.
Metering toroidal current transformers traditional, window type current transformers for measuring 50400hz currents of 5a to 15000a with secondaries of 0. The simplest form any current transformer can take is the ring type or window type, examples of which are given in the below figure which shows three commonly used shapes i. Ritz instrument transformers low voltage instrument. The model 276b has an accuracy rating of plus or minus 2% for 50100 amp cts, and plus or minus 1% over 100 amps at 60 hz. Current transformer ct construction and working principle.
A wide variety of window type current transformer options are available to you, such as. Application guide to selecting current transformers. Tape wound measuring and protection current transformers. Iec 600446 requirements for protective current transformers for.
Relays are required to perform in fault current type situations moderate accuracy over a wider range. Type ps 600v slipover large window current transformers. Bus bar quick fastening device type 1665 snapon mounting brackets for rail ts 35 din en 60715. Split core current transformer for earth fault protection. Should the shield or concentric neutral be run through the ct or routed outside the ct. The application of 600 volt class current transformers in. On window type units with low primary current ratings, where the primary conductor size is small, the ratio of the transformer can be changed by taking multiple wraps of the primary conductor through the window. The secondary wind of the ct is placed around the current flowing conductor. The core, if of a nickeliron alloy or an oriented electrical steel is almost certainly of the continuou sly wound type. Bartype and windowtype current transformers, which typically have fully distributed windings, are a good example of these types of current transformers. Traditional, window type current transformers for measuring 50400hz currents of 5a to 15000a with secondaries of 0.
Single pole voltage transformer for indoor applications. Below is a list of all current transformers available through flexcore, however, not all models are instock. Abb oem instrument transformer reference guide april 2014. Just like a normal transformer, wound type transformer has both primary and secondary windings. National electrical manufacturers association approved november 6, 2007 american national standards institute, inc. A current transformer can also be used as an input to a current relay or transmitter, or to reduce the current so that a current switch or transducer can be utilized. It is not necessary to disconnect the monitored conductor when. This guide is intended to help you select the right quantity and type of current transformers cts needed for an egauge installation. Another very common type of construction is the socalled window, through or donut type current transformer in which the core has an opening through which the conductor carrying the primary load current is passed. With full accuracy burden ratings and flexible options comparable. Support type current transformers for indoor applicationss. They are fully insulated from the high operating voltage of the system and are usually bolted to the currentcarrying device. Rs isolsec window type low voltage current transformers cts are designed for all kinds of low voltage applications where the primary cable passes through the transformer. The bar type is inserted in the circuit to be monitored.
But current transformers using hot rolled steel will. Shielded power cable and window current transformers from time to time we get asked. Typically, larger amounts of electricity require larger wires, so its important to keep window size in mind. Current transformers cable type koku are suitable for measuring of phase currents in low voltage switchgear. Window type current transformers for cable rs isolsec. The current transformer type cn14c without primary conductor, installation in sf6 gis, indoor or outdoor. Current transformer ct inside diameter goes from 15 to 160mm. We also make a substantial line of 5kv, 15kv and 25kv bar type transformers for both metering and relaying applications.
Current transformers ratio polarity types educypedia. The x1 secondary terminal is the polarity terminal figure 3. Bartype current transformer this type of current transformer uses the actual cable or busbar of the main circuit as the primary winding, which is equivalent to a single turn. Current transformers, current transformer platt electric. Open secondary testing of windowtype current transformers. The polarity marks of a current transformer indicate that when a primary current enters at the polarity mark h1 of the primary, a current in. By adding secondary turns, the same primary current will result in a decrease in secondary output. The window space factor k w is the ratio of conductor area in window to total area of window. Bar and donut type cts do not have a physical primary winding and are considered to have one primary turn. The primary winding can consist merely of the primary current conductor passing once through an aperture in the current transformer core window or bartype, or it may consist of two or more turns wound on the core together with the secondary winding wound type.
Primary current from 40 to 5000a reinforced insulation 0. A true bar type current transformer is a toroidal type transformer with a bus bar as an integral part of the current transformer which is permanently inserted through the window of the torroid. The sct983 indooroutdoor, windowtype current transformer is rated for use on 600 volt systems with 10 kv bil. By subtracting turns, the same primary current will result in. Ansi medium voltage switchgear commonly uses 600volt class window type current transformers in medium voltage circuits. The basics of current transformers nk technologies. This drytype, solidcast current transformer will operate with high accuracy for metering or relaying applications.
Current transformers support window type current transformers for indoor service, encapsulated in resin. A general overview of abbs current and voltage transformers. Simply short the secondary of the ct through the sensing window of the sensor. Instead, the line that carries the current flowing in the network is threaded through a window or hole in the toroidal transformer. Current transformer white paper the basics of current transformers ratio the ct ratio is the ratio of primary current input to secondary current output at full load. Current transformers cts can be used for monitoring current or for transforming primary current into reduced secondary. Blue sea makes some good products and has a outstanding reputation. They are fully insulated from the high operating voltage of the system and are usually bolted to the current carrying device. American national standard for instrument transformers for revenue metering 10kv bil through 350 kv bil 0. An uninsulated busbar or low voltage cable serves as the primary. The model 276b current transformer is a ringtype current transformer for currents from 50 to 1200 amps.
A windowtype current transformer is also referred to as a corebalance or fluxbalance transformer. For many years manufacturers have installed 600volt class current transformers in medium voltage switchgear. On window type units with low primary current ratings, where the primary conductor size is small, the ratio of. Activate javascript in order to enable the use of all functions of the website. This type consists of a bar of suitable size and material forming an integral part of the transformer. Piedmont makes many general purpose,600 voltwindow type transformers for both metering and relaying applications. The preferred location for the current transformers is the circuit breaker spouts. This type has a primary winding of ore than one full turn wound over the core. Will fireinduced open circuit in the secondary circuit of a woundtype ct, which is operating within its rated continuous primary current limits, result in an excessively high voltage in the secondary circuit sufficient to start a fire in the form of explosion or arcing in the circuits insulation at the location of the ct itself or at some. The correct way to specify and install current transformers. These names reveal the operating principle of the transformerneglecting magnetizing current, current will flow in the secondary such that the magnetomotive force mmf from the secondary in ampere turns will be equal and opposite to the mmf. I received the transformer very quickly and it was well package, i highly recommend this product for all your electronic needs. Current transformer basics and the current transformer.
The iron core inside the transformer is magnetized. When current flows through the primary winding, the following actions occur. Abb type geiti equivalent abb product bulletin page 50 to 2. The induced emf in a transformer, emf per turn, the window in single phase transformer contains one primary and one secondary winding. When used with our high voltage bushings the assembly has the rating of the bushing. Toroidal support type without primary conductor to be installed in medium voltage busbars without insulation. Conductor area in window, the current density is same in both the windings. The ratio of the current transformer can be modified by altering the number of secondary turns by forward or backwinding the secondary lead through the window of the current transformer. The customer shall supply current transformers when the service is metered at the transformer and when the transformer is installed in an enclosure. American national standard for instrument transformers for. Another very common type of construction is the socalled window, through or donut type current transformer in which the core has an opening through which the conductor carrying the primary load. The ct ratio is the ratio of primary current input to secondary current output at full load.
Windowtype current transformer, 250 a ac primary current. There are four typical types of current transformers. These are generally used for low voltage circuits and further classified into wound type, bar type and window type transformers. Abb type geiti equivalent abb product bulletin page 100 to 6000 na dsm 350, 360, 365 1vap428621db 2021 50 to.