Minimum Pump Run Time Calculator

Instructions

• Choose the model valve you are working with
• Enter the demand in gpm (this can be a fraction of a gallon too)
• Enter the pressure setting you would like the valve to keep constant on your system
• Enter your pressure switch cut in and cut out points

More Information

When using a Cycle Stop Valve, your pump will run continuously unless your demand falls below the minimum controlled flow: This minimum flow is determined by the model valve you are using.

• 1GPM on models CSV125-1 and CSV1A
• 3GPM on model CSV125-3
• 5GPM on all Models CSV2 and CSV3

If your demand is less than this minimum controlled flow, your pump can cycle off and on as the pressure tank is slowly filled and emptied. This worksheet has been designed to help you figure how often your pump will cycle if your demand falls below minimum flow.

Simply enter the flow rate in gallons, Cycle Stop Valve pressure setting, and pressure switch settings. A table will be created giving you tank draw-down, pump run time, and pump off time based on your specific information. (Worst case flow rate is about one half the valve's minimum flow but your entry must be less than minimum but more than 0).

Motor manufacturers publish a maximum number of starts per day* that are considered acceptable. For example, some submersible motor manufacturers recommend the following:

Maximum Number of Starts per Day

Most motor companies recommend that motors should run a minimum of one minute to dissipate heat build-up from starting current. We recommend a minimum of two minutes run time. That minimum run time will be the time it takes to fill your pressure tank at the minimum flow rated for the Cycle Stop Valve. (For example, if your valve model allows for a 1 gpm tank fill rate, you need a tank with at least 2 gallons of draw-down.) You can always use larger tanks.

Note: Please check with your motor manufacturer to get their recommended number of starts per day.