How to choose toroidal transformers?

Toroidal transformers must be chosen according to the cross-section of the busbars to be passed through the current transformer and the crow-section of the power cables. The total cross-section of the cables and busbars to be passed through the toroidal transformer must be smaller than the inner diameter of the toroidal transformer.

The cables and, if any, the neutral cable must be passed through the toroidal current transformer. The earth cables must not be passed through the toroidal transformers. The installation must be done in a manner that the cables are positioned in the centre of the toroidal transformer as much as possible. 

In the compensation systems, the reactive power is engaged through the control relay as a result of the increase in the capacitive load; shunt reactor is the compensation component that is used to compensate the capacitive load in this case that leads to an inductive effect. In recent years, the capacitive loads in electric systems have been increasing. This is particularly because of the use of LED, XLPE, UPS cables. Therefore, the use of shunt reactors together with the use of capacitors has become crucial.




1. IR adjustment scale
2. Test button
3. Stop button
4. Restart button
5. Error indicator
6. The adjustment that is locked by closing the cap


Motor safety switches act like a circuit breaker and protects the motors against overload currents and short circuit currents. They are used together with thermal and magnetic tripping. X Koren motor safety switch flow-duration curves are designed according to the load characteristics against which the protection is provided. It is the most effective and necessary system to protect motors. 

Thermal magnetic low voltage circuit breaker is a circuit protection element that provides protection of electrical facilities where electrically operated devices are located from overload currents and short circuit currents. It provides overload protection with the thermal unit and short circuit protection with the magnetic tripping unit.

The trip coil mounted on the circuit breaker is an accessory used to open the circuit breaker in case of low voltage or interruptions. This is also called tripping. 

If the neutral pole will be cut off, a 4-pole contactor must be preferred. 3-pole contactor must be used in applications such as motors, fans, pumps, etc. While mini contactors are used in gas stations, vending systems, elevator groups; If it is desired to change the direction of the motor, if it is necessary to change the generator with the mains, an inverter contactor must be used if the direction of the motor needs to be changed or mains and generator transfer is required. Modular contactors should be used in public areas such as schools, hospitals, training centres and offices since they are expected to operate silently. 

Fuses were being used for overload and short circuit protection before the MCCB’s. Both serve the same purpose. However, their areas of use and the current values they provide protection against are different. MCCBs are mostly being used for high current and loads.

In general, Surge arrester is a switchgear element that provides protection against overvoltage. It is available in different types according to the type of overvoltage against which it provides protection. 

It allows to transfer the load from one power source to another power source. It has functions such as cutting, isolating, transmitting and carrying the current. When there is a fault or short circuit at a random location in your facility, it cuts only the fault part, instead of cutting the energy of the entire facility, and ensures the continuation of the energy transfer there. It is very important to use an automatic transfer switch if the power cut may damage and disrupt the facility, the devices inside or the operation. 

It measures the reactive power need and activates/deactivates the compensation stages according to such measurement; monitors the status of the stages. It measures the current and voltage values of the network. 

X Koren automatic fuse accessories:

Low Voltage Coil:  Low voltage coil is used to automatically open the circuit breaker in case the voltage passing over the protection product (automatic fuse or residual current protection switch) to which it is connected suddenly drops or is completely cut off.

Trip coil: The trip coil is the coil that enables the protection product to be opened by the user at any time. Especially in cases where emergency stop is required, this operation may be done easily with the trip coil.

Auxiliary Contacts: Auxiliary contacts are used to remotely monitor the contact position of the protection product it is connected to and are mounted on the device, besides, it is suitable for use with fuse busbar.

Alarm Contact: The alarm contact used with the AL-XKN3 and AL-XKN6 codes acts as a warning to the user in case of sudden emergency. The device monitors the trip status.


You may find detailed drawings in X Koren Electric 2023-1 price list.

Residual current relay is not required in TN-C grounding system.