In today's machinery industry, almost every machine tool equipment needs to use control transformers. The role of the control transformer is often used for local lighting power supply, signal lights or indicator power supply of machinery and equipment, but also in electrical equipment as a control circuit power supply.
However, when using the control transformer, many people may encounter the problem that the control transformer is burned out. In general, what causes the control transformer to burn out?
(1) Control transformer transformer overload use, resulting in excessive temperature rise, has exceeded the insulation material temperature grade, thus burning transformer.
(2) the insulation between turns of the original secondary coil is destroyed or aging, inter-turn short circuit, local overheating leads to burn out.
(3) The welding part of the lead wire is virtual welding, and the contact resistance is large, leading to the local current density is too large, and the wire can even be fused.
(4) if there is a core bolt, then the bolt to the core is at least one side of the insulation, otherwise, cause magnetic short circuit, the bolt will be burned red.
The above four points are the main reason why the control transformer is prone to burn out. After we understand the four factors, we usually need to use the control transformer, as long as a little attention, can avoid the control transformer burned out.
Control transformer burning measures:
(1) For the control transformer is burned out because of overload, which requires the use of a larger capacity control transformer. The power rating of the control transformer used must be greater than that of the electrical appliance.
(2) The cause of the circuit failure is the short circuit of the low-voltage control circuit, which makes the current of the secondary coil of the control transformer too large, and exceeds the rated current of the transformer, thus burning the control transformer of the machine tool. At this point, the transformer can be added before the current limit insurance, play a protective role.
(3) Usually need to check the insulation of the line, found that the control transformer insulation is damaged or aging, to replace the transformer in time, to avoid leakage short circuit.
(4) Check whether the rotating part of the machine is jammed to avoid overflow.