Current transformer

Purchasing Current Transformers and Voltage Taps Online at EMU-Metering

As suppliers of smart and modern electricity measurement solutions, EMU Metering, of course, also has transformers in our arsenal. But what is a transformer? It is a type of converter. With its help, alternating current can either be reduced or multiplied. Along with voltage transformers and potential transformers, they belong to the group of instrument transformers. They scale high electrical currents to smaller, standardised values, which can then be easily processed by digital and intelligent measuring devices.

In the EMU-Metering online store, you will find various transformer and voltage tap-offs for the efficient measurement of your energy usage.

What is the function of a current transformer?

A standard transformer has a primary winding, a core, or gap, and a secondary winding. The alternating current in the primary circuit generates a magnetic alternating field that becomes an induced alternating current in the secondary circuit. A transformer is specified by its current ratio from the primary to the secondary side. The secondary rated or output current is typically standardised at 1 or 5 Ampere. Accordingly, EMU also offers both 1A and 5A transformers. The primary current ranges from 60 to 2000 Ampere in our devices.

What transformer designs are there?

• Plug-in transformers: The conductor to be measured is fed through the transformer’s window opening. Upon installation, the primary conductor must be disrupted. For this reason, this design is primarily used in new installations of electrical systems. The installation can occur either via lines or conductor rails.
• Split-core current transformer: The splittable transformers are simply placed around the conductor. These devices are particularly used if the current circuit cannot be interrupted without significant effort. Using these transformers enables you to easily retrofit your measuring instruments. Split-core current transformers can also be removed quickly.
• Multipolar transformers This type of transformer has additional or extended openings through which multiple conductors can be fed at the same time. These multi-phase transformers total the current of all conductors. This measurement method is particularly beneficial for differential current measurements and safety equipment.
• Winding transformers: They have connections on both sides and are used for smaller currents of up to 20 Ampere.

How do you choose and install the right current transformer?

Which transformer is right for you depends, among other factors, on the connection type on the secondary circuit. Instrument transformers can be fastened with bushing or screw connections, as well as spring balancer, screw, or plug-in terminals. The first option is particularly suitable when the transformer is permanently installed. The latter are often use for measuring devices and lines that are frequently clamped on and off.

Please ensure that the system is not live and is protected against being energized before installing the transformer. Very high voltages flow through transformers when they are in use - this constitutes a danger to life for humans. Transformers should therefore be exclusively installed by electricians.

In addition, the secondary circuit of the measuring device should never be open as long as current still flows through the primary winding. In this condition, induction can generate high voltages. This not only harbours health risks for people, but devices can also be damaged due to inattention, which can impact their function. For these reasons, a load must always be placed on the transformer, or it must be short-circuited.

How is current measured using transformers?

To measure alternate current, you need a transformer. A strong current is transformed to a weaker current using a magnetic holder. EMU-Metering transformers ensure efficient measuring. Typically, the primary coil of the transformer only has a few windings, whereas the secondary coil has a large number of windings. The extent to which the current load must be reduced depends on this relationship between the primary and secondary coil.

Does EMU Metering only sell current transformers?

Of course not. Our online store offers everything you need for the accurate measurement of energy usage. From transformers to energy meters, to voltage tap-offs and the corresponding system technology, our products ensure a smooth electricity circuit. Direct readouts or remote maintenance - we are energized and our electrifying product range awaits you. Please feel free to contact us. We look forward to hearing from you and receiving your order.