3-level float switch PZM-20 EXT10000230

Liquid level automatic control in tanks

The PZM-20 float switch is a reliable device designed to detect the presence of electrically conductive liquids. Its main function is to automatically control the operation of pumps, maintaining a constant liquid level in tanks – an ideal solution for both installers and end users. The device works with float switches SZH-01 (available separately), which, when immersed in liquid, activate one of three built-in relays.

Functionality and application

PZM-20 finds wide application in automatic pump control systems, e.g. in:

• Rainwater tanks – automatic pumping of water to the irrigation system or other purposes.
• Septic tanks and sewage pumping stations – protecting the pump from running dry and maintaining an appropriate fluid level.
• Cooling systems – monitoring the coolant level and automatic replenishment.
• Industrial processes requiring precise liquid level control.

Thanks to three independent relays, it is possible to define several alarm levels or control different devices depending on the liquid level. The detection sensitivity of the probes can be adjusted in the range of 1 ÷ 190 kΩ, allowing the device to be adapted to different types of liquids and operating conditions.

Construction and mounting

The PZM-20 relay is designed for mounting on a TH35 rail, which facilitates its integration with the existing electrical installation. The housing with a width of 3 modules provides compact dimensions and an aesthetic appearance. The status of each relay is indicated by a dedicated LED (PK1, PK2, PK3), and the presence of 230 V AC power is indicated by a green LED. NO/NC switching contacts increase the flexibility of the device's applications, allowing the connection of various circuits. The device has contacts with a maximum load capacity of 16A, ensuring safe and reliable operation with various receivers.