The electrical control system of the hydraulic press is primarily composed of automotive relays, AC contactors, push buttons, limit switches, and an electrical control cabinet. The principle of the hydraulic press is that the hydraulic transmission system is controlled by an electronic control system, which is then operated by the hydraulic press control system for the main machine's operation. The main machine activates the limit switch, feeding back data signals to the electronic control system to complete the cyclic operation. Next, I will discuss the method for checking whether the hydraulic press surface is leaking oil.

The filter can interrupt input interference and interference induced on the signal transmission lines. The commonly used filters are low-pass filters and DC filters, which are typically installed between the power supply and CNC devices of hydraulic machines.

2. Shielding Methods. To prevent four-column hydraulic presses and their components from being affected by external electromagnetic fields, isolation shielding measures are commonly employed, which involve electromagnetic shielding or discharge through reflection or absorption.

3. Grounding Method: The hydraulic press connects its outer shell to the earth. For protective grounding, if the system grounding of the hydraulic press is connected to the earth as the system grounding, anti-interference can also be achieved through protective grounding or system grounding methods.

4. The physical isolation method increases the distance between the hydraulic press's disturbed circuit or device and the interference source. Since the interference intensity is inversely proportional to the square of the distance, it is recommended to use a stable power supply. To suppress the noise of the hydraulic press's power supply and interference between the power supply and the grounding cable, an isolation can be connected between the power supply and the CNC device.