Eliminate Pump Chatter with DCR-1006 Controller

Constant on-off cycling (chatter) in tank level pump control applications can add unnecessary wear and tear and lessen the life of a pump. In addition, the electrical surcharges can be quite high.

Chatter is usually seen in level control applications where the liquid is turbulent, the liquid level is changing rapidly, and only a single trip relay output point is being used. With only a single trip relay output point, the rapid rising and falling of the liquid causes the relay output to fluctuate the on and off state, causing pump chatter.

A way to solve this problem is by using the DCR-1005/1006 controller with the DST series of ultrasonic sensors and programming a relay trip point on the controller with the Begin Trip, End Trip (High and Low) features and by setting the proper Trip Type which will add hysteresis between the Begin Trip and End Trip.

Using the following tank level application parameters, here are the steps to program the DCR-1005/1006 controller using hysteresis to eliminate pump chatter.

Note: For this example, we will be using Relay 1 on the controller.

Application: Tank level to be kept full
Tank Height: 10 ft.
Sensor Blanking Distance: 1 ft.
Full level: 1 ft. from sensor face (10 ft. level from bottom of tank)
Empty Level: 11 ft. from sensor face (bottom of tank)

• Step 1: Press the Mode button until the number 1 is displayed. Change the value to 2 (feet) with the Value button.
• Step 2: Press the Mode button until the number 3 is displayed. Change the value to 1 (tells sensor to measure distance) with the Value button.
• Step 3: Press the Mode button until the number 5 is displayed. Change the value to 1 (feet, for blanking distance) using the Value button.
• Step 4: Press the Mode button until the number 12 is displayed. Change the value to 1 (feet, for Begin Trip 1) using the Value button.
• Step 5: Press the Mode button until the number 13 is displayed. Change the value to 11 (feet, for End Trip 1) with the Value button.
• Step 6: Press the Mode button until the number 14 is displayed. Change the value to 5 (Trip Type; Hysteresis Far) using the Value button.

When the tank is empty, the relay output activates and the pump will start filling the tank with liquid. When the liquid reaches the full level (1 ft. from sensor face), the relay output will deactivate and turn the pump off.

The pump will stay off until the tank is empty, then the filling process will repeat. The delay of the pump until the tank is empty is called hysteresis. Using the DCR-1006 controller to program hysteresis will extend the life of the pump considerably.

Contact us if you have any questions about pump control, hysteresis, or the DCR-1006!