Franklin Electric MonoDrive, Owner'S Manual

Page: 16 / 184

INSTALLATION AND SETUP
Installation Process
16
Minimum Pressure Tank and Supply Pipe Sizing
A VFD system needs only a small pressure tank to maintain constant pressure, although a larger
tank may be used. If adding a SubDrive/MonoDrive to a conventional system with an existing large
tank, refer to
“Advanced Options” on page 38 .
When using a standard pressure sensor, system performance can be adjusted using the FE Connect
mobile app to select tank size. Refer to
“Advanced Options” on page 38 .
The pressure tank pre-charge setting should be 70% of the targeted system pressure. To check the
tank’s pre-charge, de-pressurize the water system by opening a tap with the drive off. Measure
with a pressure gauge at the inflation valve and make any necessary adjustments.
Refer to the following recommendations for best performance.
Submersible Pump Applications
Surface Pump Applications
Minimum Supply Pipe Sizes
The minimum supply pipe diameter past the pressure sensor (transducer) should be selected not
to exceed a maximum velocity of 8 feet per second (2.4 m/s) based on the flow rate of the system.
Pump Flow Rating VFD Model Minimum Tank Size
Less than 12 gpm (45.4 lpm)
SubDrive 15 or MonoDrive 2 gallons (7.6 liters)
SubDrive 20 4 gallons (15.1 liters)
SubDrive 30 or MonoDriveXT 4 gallons (15.1 liters)
SubDrive 50 8 gallons (30.3 liters)
12 gpm (45.4 lpm) and higher
SubDrive 15 or MonoDrive 4 gallons (15.1 liters)
SubDrive 20 8 gallons (30.3 liters)
SubDrive 30 or MonoDriveXT 8 gallons (30.3 liters)
SubDrive 50 20 gallons (75.7 liters)
Maximum Pump Flow Minimum Tank Size
10 GPM 2 gallons (7.6 liters)
20 GPM 4 gallons (15.1 liters)
30 GPM 4 gallons (15.1 liters)
40 GPM 8 gallons (30.3 liters)
Maximum GPM (lpm) Minimum Pipe Diameter
11.0 (41.6) 3/4”
19.6 (74.2)
1”
30.6 (115.8) 1-1/4”
44.1 (166.9) 1-1/2”
78.3 (296.4) 2”
176.3 (667.4) 2-1/2”