Skip to main content

Split core CTs and why size matters


Current Transducers
Current Transducers (CTs) ar a essential element of power observance. They come during a style of formats, sizes, current ratings and accuracy levels. The side we'd wish to concentrate on here is size, specifically inside diameter.
The inside diameter (ID) is the width of the opening in the CT that the conductor goes through. It must be large enough to fit around the conductor, however choosing too large of a CT can create other issues. As the graphic above indicates, the overall dimensions of the CT grow substantially as the ID gets bigger.

Current Transducer Types

Current sensors can be either open-loop or closed-loop.
Open-Loop Sensor: This type measures AC and DC currents and provides electrical isolation between the circuit being measured and the output of the sensor. Open-loop current sensors are generally preferred in battery-powered circuits.
Closed-Loop Sensor: The Closed-Loop sensor is sometimes called a ’Zero-Flux’ sensor because it features a Hall-Effect sensor that feeds back an opposing current into a secondary coil, wound on the magnetic core to zero the flux produced in the magnetic core by the primary current. Closed-loop sensors are often used when high accuracy is essential.
Current rating
Be sure to use a CT with a current rating as close to the actual current being monitored as possible to maximize accuracy at the lowest possible load. ACT will be accurate across some portion of its range.
Inside diameter
CTs of the same amperage come in different sizes. For example, RS Components offers 200 amp CTs with 24mm, 36mm and 50mm IDs. The chart below shows that a 200A CT with a 50mm ID is much larger than one with a 24mm ID. Since space inside electrical equipment is often tight, using a CT that is larger than needed can create problems as well.
CT sizing summary
Most customers will try to match the amperage of the Current Transducers to the rating of the over-current protection on the circuit. You need to know both the circumference of the conductor(s) that the CT has to fit around (to determine the minimum acceptable ID) and the amount of available space in the panel where the CTs will be installed. If the conductor is very large or the space is particularly tight, a Rogowski coil ("rope CT") might be the best choice.

Labels:

Comments

Post a Comment

Popular posts from this blog

Different types of Limit Switches

Rotary Geared Limit Switches The operating of the Limit Switch is to prevent the mechanism or drive at the intense forward/reverse positions. The Limit Switches are significantly suited to use on reversing drives like a hoist, winches, rolling mills and various other mechanisms used in steel plants such as coke ovens, feeding machinery, valve drives etc. The contacts of Limit Switches are forty amps rated ceaselessly at 500 Volts A. C. The Limit switch is often supplied with two NC contacts or four NC contacts or (2 NO + two NC) contacts as per the need. For Series Limit Switches are shields are provided. The frequency of switching of each contact is suitable for a maximum of 720 operations per hour. The speed of the driving shaft rotation shouldn't be over 60 rpm. Features:- High durable standards Optimum performance Easy to install Counter Weight Limit Switches A metal structure offers the required stability to Counter Weight Limit Switches that job on heavy c...
Post a Comment
Read more

What is MOSFETs: Types & How to MOSFET as a switch

MOSFET stands for metal-oxide-semiconductor-field-effect transistor. It is a special kind of field-effect transistor (FET). The MOSFETs could be a voltage controlled device. The MOSFET has “gate“, “Drain” and “Source” terminals rather than a “base”, “collector”, and “emitter” terminals in a very bipolar transistor. By applying the voltage at the gate, it generates AN electrical field to control the current flow through the channel between drain and supply, and there's no current flow from the gate into the MOSFET. The power MOSFETs are special to handle the high level of powers. The power MOSFETs is widely used in the n-channel enhancement mode, p-channel enhancement mode, and in the nature of n-channel depletion mode. Here we've got explained regarding the N-channel power MOSFET. Basic Statures of Power MOSFET There is three main basic status in the power MOSFETs. ·          On sate resistance ·     ...
Post a Comment
Read more

Solid State Relay AC & DC Input Circuit

Solid State Relays are semiconductor equivalents of the mechanical device relay and may be accustomed control electrical masses while not the utilization of moving parts. a normal electro-mechanical relay, SSR’s provide complete electrical isolation between their input and output contacts with its output acting as a conventional electrical switch in that it has very high, almost infinite resistance once nonconductive (open), and a really low resistance once conducting (closed). Solid State Relays can be designed to switch both AC or DC currents by using an SCR, TRIAC, or switching transistor output instead of the usual mechanical normally-open (NO) contacts. Solid State Relay DC Input Circuit When utilizing mechanical contacts, switches, push-catches, other hand-off contacts, and so forth, as the initiating signal, the supply voltage utilized can be equivalent to the SSR's base information voltage esteem, though when utilizing strong state gadgets, for example, trans...
Post a Comment
Read more