Installation Requirements and Fixing Methods of Split Core Current Transformers

The fixing method of the split-core current transformers

The split-core CT (current transformer) is commonly used in equipment, with good induction effect, can improve the efficiency of equipment application, and has good effect in controlling current, completing up and down voltage conversion.

In order to make it run smoothly and avoid vibration, how should we maintain it?

Fix with positioning screws: The fixing screws are locked by two positioning screws with a gap of 90 degrees. In the traditional fixing method, the front end of the screw contacts with the shaft, which may damage the shaft or make it difficult to disassemble.
Fix with clamping screws: Use the tightening force of the hexagonal concave head bolts to shrink the gap and clamp the shaft of the split-core CT (current transformer). This method is easy to fix and disassemble, and will not cause damage to the axis.
Keyway fixing: Suitable for high torque transmission. In order to avoid axial sliding, it is usually applied separately with positioning screw fixing and clamping screw fixing.
D-hole fixing: If the motor shaft is D-shaped and the fixing screw cannot be fixed, the split-core CT (current transformer) can be processed into a D-hole corresponding to the size of the motor shaft, and fixed with a fixing screw, so there is no need to worry about slippage.
Fix with shrink sleeve: Tighten the four positioning screws on the end face to press the accounting sleeve, which is suitable for connecting and fixing some high-torque stepper motors and servo motors.

Ordinary split-core current transformers can switch sensitively between high voltage and low voltage, so that the equipment can switch back and forth under different voltages. In terms of maintaining equipment and user safety, they are good transformers. It is mainly fixed by these methods.

Installation requirements of split-core current transformers

In the normal use of the split-core current transformers, everyone should install them according to the instructions and other technical requirements.

Follow the construction drawing, wire the connections correctly, and the numbered tags at both ends of the wire should be clear, and the range of the tags should meet the specified requirements.
The current and voltage circuits should be grounded at the outlet of the secondary side of the transformer. The voltage circuit should be protected by a fuse.
There should be no joints in the secondary circuit wires in the cabinet, and there should be no joints in the middle of the control cables or wires. If there are joints, they should be connected through their long connection boxes.
The insulation of the secondary circuit wires of the split-core CT (current transformer) should be good, and there should be no mixing between the voltage circuit and the current circuit.
The placement of the secondary circuit wires should be designed beautifully, and the connection screws between the wires and electrical components or junction boxes should be free of looseness. The interval between the clamping points of the bundled wires should meet the specified requirements.
It cannot be reversed, and the phase sequence and phase difference should meet the design and regulatory requirements. For the wiring of the differential protection transformer, the phase vector diagram of the two arms should be measured before commissioning to check the correctness of the wiring.
The secondary circuit wires or cables should be made of copper wire. The cross-sectional area of the split-core current transformers return line should not be less than 2.5mm2, and the cross-sectional area of the voltage transformer return line should not be less than 1.5mm2. A special current terminal should be selected for the outlet junction box of the split-core current transformers, and the unused secondary winding of the transformer should be short-circuited and grounded at the junction board.

Related Articles about Acrel

Do you Know a DC kWh Power Meter? Challenges of Safety and Efficiency in Operating Room Electrical Systems Energy Data Visualization and Intelligent Analysis for Telecom Towers On the Road to Efficiency: Digital Multifunction Meters in Automotive Manufacturing