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Well Control: Municipal and Rural Water Level Control 1644:

This Water Level Control is primarily used for the monitoring and control of reservoir water levels for municipal and rural water districts. It is an affordable and reliable way for these municipal and rural water distircts to precisely monitor water levels and to ensure their water systems remain at the proper levels over time.

Well Control informational package in PDF format Well Level Control diagram

The Herrin Design Model 1644 Well System Pump Control is designed to provide a cost effective means of controlling water system reservoir levels. Through precise monitoring, the Well Control is able to reliably sense reservoir water levels by measuring water pressure at the well head. By monitoring reservoir levels at the well head, it is possible to mount the water system controls in one location, eliminating the costly communications link--leased lines or buried cables--between reservoir level sensors and the pumps. Typically, mechanical sensors at the reservoir deteriorate or are broken frequently due to weather; and communications lines are a large, continued expense.

The Well Control tolerates temporary variations in water pressure due to surges and usage. The pump will not start until there is a constant low pressure level for 2-3 (variable) minutes (OFF TIME). This insures the pumps are activated only when necessary. Once the pump is turned on, it remains on for a preset period of time--up to 24 hours (ON TIME). During the pump cycle, the control does not rely on water pressure measurements to indicate if the reservoir is full. This feature eliminates sporadic pumping due to pressure variations created during the pumping cycle.

This combination of exacting pressure sensors and precise timing provides a very economical means of controlling community water system reservoir levels.

Click here to see a photo of an actual well control installation

Well Control System Components

Well Control Standard features

 Well Level Installation diagram

Well Control Specifications


Well Control
Pressure Switch

8" x 6 ½" x 4"
4" x 4" x 3"

Relay closure to energize pump contactor (10A, 240 VAC max)
Pressure switch

Well Control Warranty

The Herrin Design 1644 Well Control is a quality product. If proven to be defective in workmanship or materials within 2 years from the date of purchase, it will be repaired or replaced at the manufacturer's option at the factory. Warranty service on
your Herrin Design equipment may be performed only by an authorized Herrin Dealer Representative.

Unauthorized service procedures or parts will void and cancel your warranty.

This warranty is given in lieu of all other warranties, either expressed or implied, and neither seller nor manufacturer shall be liable for any direct, incidental or consequential loss or damage arising out of the failure of the product to operate.

More information about the Model 1644 Water System Level Control:

Installing and maintaining a tank or reservoir water level sensing device can be expensive for small community systems. The cost of maintaining underground wiring, leasing telephone lines or maintaining radio links can accumulate to significant cost levels in just a few years. The Model 1644 provides the means to reliably sense tank water level by measuring the water pressure at the well head. This gives the advantage of having all the controls for the water system in one place, eliminating the communication link between the reservoir and the pumps. With very little loss in accuracy, The Model 1644 Control uses accurate pressure sensing in combination with precise timing to provide a reliable, economical alternative for small community water systems.

Well Control Operation

The 1644 control monitors system water pressure using a high quality, tight deadband pressure switch. Variations in pressure resulting from usage and pumping surges are filtered out by an adjustable time delay that allows the 1644 to ignore these relatively short pressure variations. This time delay (OFF TIME) is typically set for three or four minutes but the setting will vary with system characteristics. When the system pressure drops below a preset limit the pressure switch alerts the 1644 control. The PSW indicator turns on. The control will start the pump when this low pressure alert exceeds the OFF TIME . The PMP indicator turns on for the duration of the pumping cycle.

Well Control Pressure Switch

Connect the NC and C terminals of the Pressure Switch to terminals 4 and 5 of the 1644 Control Box (non-polarized). Adjust the pressure by first pumping the reservoir full. At the full point the pressure adjustment is set so the pressure switch plunger is just depressed and the PSW indicator is off. To adjust this threshold point loosen the set screw below the 5/8" hex nut, then adjust the 5/8" hex nut slowly so that the switch is OFF(plunger depressed, PSW indicator on). There is some slack in the adjustment between ON and OFF. Set the adjustment for 1/2 the difference between ON and OFF. At this threshold point the indicator will flash on and off due to usage but it should be predominately off.

Well Control Timer Adjustment


During normal operation the pressure switch will click on and off due to pressure changes in the water system. The OFF TIME is a method of ignoring these normal oscillations. As the reservoir water level lowers, the pressure switch will stay on longer. Eventually, the pressure switch will stay on long enough to match the OFF TIME setting on the timer. At that point, the pump will be turned on.

If the OFF TIME is set too short, then the pump may turn on too early which will lead to overflow. If the time is too long the reservoir may drop below desired levels. A typical OFF TIME seems to be two to four minutes. You should be able to watch the system's pressure gauge whenever the pump turns off and observe the time it takes for the system to stabilize.


The ON TIME is the time that the pump runs. Knowing the pump GPM and the dimensions of the reservoir you can calculate the time it would take to fill the tank from the turn on point established in the PRESSURE SWITCH section. Or set this time by allowing the tank to drop enough to turn the pump on and measure the time it takes to fill the reservoir. This is the ON TIME . If over fill is a critical problem, establish this pumping time based on a low usage or no usage time (usually early morning hours)

Parts list for Well Level ControlWell Level Control diagram











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