Product Description Up to 18 configurations to choose from; FM0-SMD01 through FM10-SMD-18 are configured with either both Upper and Lower Levels are Normally Open (NO) or Normally Closed (NC) contacts Normally Open = Pump Down Normally Closed = Pump Up FM0-SMD Switches are Ideal for Pump up or Pump down applications (see Pup/Pdn PDF) A Pump-Up Float Switch, also known as ‘Normally Closed’, opens the circuit on the rise and is typically used to turn the pump off when the float is in the up position. So, a pump could be set to turn off when the water level in the storage tank reaches a predetermined high level. Therefore, a pump-up float switch is often used to fill a water tank. A Pump-Down Float Switch, also known as ‘Normally Open’, closes the circuit on the rise and is typically used to turn the pump off when the float is in the down position. So, a pump could be set to turn off when the water level in the storage tank reaches a predetermined low level. Therefore, a pump-down float switch is often used to empty a water tank. Magnetic Reed Switch Technology and Protection Normal Positions of Float Switches
