Frequently Asked Questions - Franklin Electric Inline 400 Owner's Manual

Inline Pressure Boosting System

Frequently Asked Questions

What causes the Inline to start boosting?
The Inline is equipped with a flow sensor and dual pressure switches. It will turn on when the:
• Discharge pressure drops below 40 psi or
• Discharge pressure becomes equal to the inlet pressure
This starting logic allows for the pressure tank to fully discharge before turning the Inline system
unit ON. This will minimize power consumption and increase product life by accommodating small
intermittent water usage or leakage.
What causes the Inline System to stop boosting?
The Inline system stops boosting when the demand for water drops below the ½ gallon- per-
minute flow rate (pump will turn off in 10 seconds after the flow stops). The unit can also be
manually shut down during normal operation by pressing the button on the cap of the unit.
What internal system protection does the Inline offer?
The Inline system monitors several different functions in order to protect the unit should any of the
following conditions occur during normal operation:
• Over Voltage (+10% of rated)
• Under Voltage (-10% of rated)
• Dry Run (i.e. motor is running but no pressure is being developed)
• Overheat (greater than 120 °F internal water temperature)
These are also Inline 400 Faults which are indicated by a red blinking light on the control cap.
What is the purpose of the pressure tank?
The pressure tank serves two purposes.
1. It allows for small volumes of water to be used without starting the Inline.
2. It adds a pressure buffer to the system in order to absorb undesired pressure spikes
fluctuations.
It is recommended that the tank be charged to 38 psi when installed.
What is the maximum inlet pressure?
The maximum internal pressure rating of the Inline is 100 psi. Therefore, the maximum inlet
pressure when added to the maximum Inline pump pressure (see performance chart) must not
exceed 100 psi. The Inline unit incorporates an internal pressure switch that will not allow the unit
to turn ON if the inlet pressure exceeds 40 psi either before or during desired operation. Example:
If you wish to use this booster in an application with 45 psi incoming, it is recommended to install
a Pressure Reducing Valve (PRV) on the inlet side of the unit. The PRV would be used to maintain
a constant pressure below the cut-in pressure and could be used to limit the maximum pressure
created.
16
or