Liquid Level Relay, Water Level Controller

Liquid level relay is a very practical industrial control component. Its core function can be summarized as: automatically controlling the start and stop of water pumps, valves, or other equipment based on the level of liquid, thereby achieving automatic control of liquid level. Simply put, it is like an automatic switch triggered by the "water level". The liquid level relay mainly achieves the following two functions: 1. Automatic water supply/drainage ·Water supply (low start, high stop): When the liquid level drops to a low level, the water pump automatically starts to supply water; When the liquid level rises to a high level, the water pump will automatically stop. ·Drainage (high start low stop): When the liquid level rises to a high level, the drainage pump automatically starts to drain water; When the liquid level drops to a low level, the drainage pump will automatically stop. 2. Liquid level alarm and protection ·Overflow alarm: When the liquid level exceeds the set ultra-high water level, an audible and visual alarm is triggered to remind operators to pay attention and prevent container overflow. ·Dry pumping protection: When the liquid level is lower than the set ultra-low water level, the water pump is forcibly stopped to prevent it from "dry running" and burning out in an anhydrous state. Liquid level relays are widely used in any situation where automatic control of liquid level is required: ·Domestic water supply: automatic replenishment control of water tanks on residential rooftops and underground reservoirs. ·Drainage system: automatic drainage of basement sump and sewage treatment tank. ·Industrial field: Level control of cooling towers, boilers, and chemical liquid storage tanks in factories. ·Agricultural irrigation: automatic management of farmland water towers and irrigation reservoirs. The liquid level relay system usually consists of three parts: 1. Controller (relay body): This is the core brain, which contains electronic circuits and relays inside. It receives signals from sensors and controls the on/off of the output circuit according to preset logic. 2. Sensor (liquid level detection part): used to detect changes in liquid level. There are two most common ways: ·Electrode rod/probe type: utilizing the conductivity of liquid. When the liquid level comes into contact with metal electrode rods of different lengths, a current loop is formed to send a signal to the controller. ·Float switch type: By using a float that rises and falls with the liquid level, its internal magnetic mechanism drives the reed switch to turn on and off, thereby emitting a switch signal. 3. Executor: Controlled equipment such as water pumps, solenoid valves, etc.