Question

Develop a ladder logic diagram for a PLC for a two level switch sensors in a water tank. The logic is that the second switch when it looses connection the water pump will turn off and a solenoid valve will permit water to travel form the reservoir to the tank until it reaches the first switch to turn the valve and turn on the water pump. Use a ladder diagram software or a PLC software to describe this.

Answer 1

To create a ladder logic diagram for a PLC controlling a water pump with two level switches, you need to define the conditions for turning on/off the pump and solenoid valve based on water level. When water falls below the upper switch, the pump shuts off, and the valve opens to fill the tank until reaching the lower switch, then the valve closes and the pump activates.

Step-by-step explanation:

To develop a ladder logic diagram for a PLC that controls a water pump based on two-level switch sensors in a water tank, you will need various components such as switches, a pump, and a solenoid valve. The logic is such that when the second (higher) level switch loses connection (indicating the water level has fallen below that switch), the water pump should turn off. Then, the solenoid valve should open to allow water to flow from the reservoir into the tank until the water reaches the first (lower) level switch. Once the water level reaches the first switch, the valve should close and the pump should turn on to lift the water for use or to transfer it to another tank.

Here is a simplified outline of what the logic could look like in ladder diagram form:

• Input 1 (I1) connected to the lower level switch
• Input 2 (I2) connected to the higher level switch
• Output 1 (O1) controlling the water pump
• Output 2 (O2) controlling the solenoid valve

The ladder logic would be set up so that:

1. If I2 is off (no connection, water level below the higher switch), then O1 is off, and O2 is on, allowing water to fill the tank.
2. Once I1 is on (connection made, water level reaches the lower switch), O2 would turn off, stopping the flow from the reservoir.
3. Following this, when I2 makes connection again (indicating the water level has reached the higher switch), O1 would turn on, activating the pump.

This sequence ensures that the water level between the two switches maintains an adequate volume without overflowing or falling below a minimum threshold. Practical implementation would require additional logic for safety, manual override, and possibly other functions based on the specific application needs.