What are tool transformers?
instruments transformers proportionally obscure or reduce large voltage and current values to be safely used on sensitive tools and components. These devices and components include ammeters, voltmeters and overcurrent relays. The devices of the devices fall into two different categories: potential and current transformers. The potential transformer (PT) is used to supply low voltage to voltmeters and the transformer current (CT) adds manageable current bathtubs for ammeters and overcurrent relays. PTS can be placed together with a high voltage supply in local starting panels or remotely in instrument control panels, while CT is generally located together. Three -phase equipment, such as electric motors in industrial installations, normally runs at 380 or 500 volts and often draws several hundred amps during operation. The tentative voltmeter has a maximum rated voltage of 110 to 150 V and could never measure these voltages directly. In order to use these components, the exact traInstruments Nsformers proportionally reduce high voltages and currents to safe values. Instrument transformers also allow the installation of all required instrumentation in the control rooms and monitoring devices with present only low -floor cabling.
Installation transformers fall into one of two separate categories. The first is a potential transformer that adds low value voltage per voltmeters. PT is usually equipped with four terminals; Two for incoming high voltage and two for reduced instrument voltage. Incoming or primary PT wires are connected in parallel across high voltage power supply. This means that it can be placed remotely in the control rooms, although it can often be mounted in the voltage of the starting panels where local voltage indications are required.
The second type is the current transformer. This variant of the device transformer measures the TVD and used to control ammeters and overcurrent protective relays. Typical CT differs from its siblings of relaxing voltage in that it is connected in a series with power supply and usually uses induced primary feed and not a direct connection. To achieve this goal, CT is produced with a hole in the center, through which a high voltage cable leads. The current passing through the cable induces the electromagnetic field in the primary CT winding, which is then disappeared by its secondary winding and is supplied to the tools through two CT output terminals.
devices are available in a large number of suggestions and evaluation and can be tailored to meet all users' requirements. Ordinary PTS and CTS are relatively small components, rarely measuring more than a few inches. However, large, oil spa -lodransformers are commonly used to facilitate low voltage measurements in the primary grid distribution applications.