What to do if the high-frequency induction heating equipment has overcurrent

First of all, make it clear that the logic of the design of Tongcheng’s high-frequency heating machine, since the alarm system is designed, it must have its meaning and value. The basic starting point of this system alert is,

A. It indicates that there has been a failure, please stop the machine as soon as possible for troubleshooting.

B. Point out the fault point, you can more quickly determine the location of the fault, and provide help for maintenance. Therefore, when an alarm occurs, please stop the machine for inspection and troubleshooting in time to avoid greater losses.

Causes of overcurrent:

The self-made induction coil has incorrect shape and size, the distance between the workpiece and the induction coil is too small, there is a short circuit between the workpiece and the induction coil or the induction coil itself, and the prepared induction coil is affected by the customer’s metal fixture during use or is close to it. The influence of metal objects, etc.

Approach:

1. Re-make the induction coil, the coupling gap between the induction coil and the heating part should be 1-3mm (when the heating area is small)

It is advisable to use a round copper tube or square copper tube with a thickness of 1-1.5mm and above φ5 ​​to wind the induction coil.

2. Solve the short circuit and ignition of the induction coil

3. When materials with poor magnetic permeability such as copper and aluminum are inductively heated, the number of induction coils should be increased

4. The equipment should avoid sunlight, rain, humidity, etc.

Check whether the heating power matches the protector. If the match is correct, check whether the operation is correct, mainly the heating time.

5. Change to a larger protector switch, provided that the heating system is normal

C. Start-up overcurrent: The reasons are generally:

1. IGBT breakdown

2. Driver board failure

3. Caused by balancing small magnetic rings

4. The circuit board is wet

5. The power supply of the drive board is abnormal

6. Short circuit of the sensor

Approach:

1. Replace the driver board and IGBT, remove the small magnetic ring from the lead, check the waterway, whether the water box is blocked, blow the board used with a hair dryer, and measure the voltage

2. Overcurrent after using for a period of time after booting: the reason is generally poor heat dissipation of the driver. Treatment method: reapply silicone grease; check whether the waterway is blocked.

D. Power increase over current:

(1) Transformer ignition

(2) The sensor does not match

(3) Drive board failure

Approach:

1. The inside of the machine and the induction coil must be cooled by water, and the water source must be clean, so as not to block the cooling pipe and cause the machine to overheat and damage.

The temperature of the cooling water should not be too high, it should be lower than 45℃.

2. Do not use waterproof raw material tape when installing the induction coil to avoid bad electrical connection

Do not change the induction coil soldering to brazing or silver soldering!

3. There are many reasons for the influence of the number of turns of the induction coil on the current, and it will also cause overcurrent.

First of all, it is related to the material of the workpiece;

Secondly, if the coil is too large, the current will also be small;

Once again, the coil is too small, the more the number of turns the coil, the smaller the current will be.