Variable Frequency Controller

Variable Speed

HighVFC - Hero.psd
Variable Frequency Controller

Variable Speed

Variable speed pumps are controlled by the VFC™ variable frequency controller which provides control for both 2 Hp and 4 Hp variable speed submersible turbine pumps.

MagVFC - Highlight.psd


As station size and volumes have continued to grow, more marketers are choosing variable speed to meet the high fuel throughput demands while gaining additional benefits only variable speed can offer.

Higher Flow Rates

The MagVFC™ variable speed controller ramps the STP up and down as-needed to provide optimal flow rates at all fueling points. The result is faster, more consistent flow rates than fixed speed systems at virtually the same cost of ownership.

Minimize Hydraulic Hammer

Hydraulic hammer is a sudden pressure spike resulting from a stoppage in flow that can be exaggerated in fixed speed pumping systems. A variable speed system significantly minimizes the effects of hydraulic hammer like accelerated wear on equipment.

Energy Efficiency

Because a variable speed system is constantly providing only the necessary power to achieve desired flow rates, the system only consumes as much energy as is needed. Get energy savings during non-peak business hours and increased flow during peak hours.

MagVFC - Higher Flow Rates.psd

Variable speed systems ramp up the system’s horsepower as needed to provide optimal flow rates at fueling points. This results in faster and more consistent flow rates at peak business times compared to fixed speed systems.

Higher Throughput

Variable speed systems deliver faster and more reliable flow rates than fixed speed systems resulting in higher throughput at virtually the same total cost of ownership.

Meet Your Needs

The STP can be adjusted at installation to perform at a maximum per-nozzle flow rate of 10 gpm (38 lpm) based on the specifications of your piping and dispensing system.

2 Hp or 4 Hp

Variable speed 2 Hp pumps provide constant 10 gpm (38 lpm) for up to eight fueling positions operating simultaneously whil 4 Hp pumps 10 gpm (38 lpm) for up to 12 fueling position.

MagVFC - Hydraulic Hammer.psd

Hydraulic hammer is as a rapid pressure spike that is the result of a sudden stoppage in flow in a pressurized piping system. Hydraulic hammer can be exaggerated in a system that utilizes a high pressure fixed speed pump. Variable speed helps to minimize these effects and the wear it can cause on system components.

Hydraulic Hammer

A fixed speed pumping system is incapable of changing the flow rate dependent upon demand and as a result, hydraulic hammer is likely to result when flow is interrupted.

System Fatigue

Hydraulic hammer may result in system fatigue and intensified wear to system components such as diaphragm valves in multi-product dispensers, leak detectors or hanging hardware.

Minimize The Effects

A variable speed STP will ramp up and down to provide only the pressure required to meet demand, significantly minimizing the effects of hydraulic hammer.

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The MagVFC™ variable frequency controller features a dual 7-segment display that displays running status and fault codes. A fault history on the controller also provides an enhanced troubleshooting process with faults like:

MagVFC - Fault Highlight.psd

Fault Detection Display Codes

A fault history on the controller also provides an enhanced troubleshooting process with faults like these:

MagVFC - Fault - UL.psd

UL = Underload: Dry run or blocked PMA intake

MagVFC - Fault - LI.psd

LI = Low Incoming: Input power under voltage

MagVFC - Fault - LU.psd

LU = Locked Up: Overload at PMA startup

MagVFC - Fault - SC.psd

SC = Short Circuit: Short typically from controller to PMA

MagVFC - Fault - SU.psd

SU = Shorted Upper: Short typically in controller

MagVFC - Fault - OC.psd

OC = Open Circuit: Broken connection to PMA

MagVFC - Fault - Er.psd

Er = Extended Run: No power change for 60 minutes

MagVFC - Fault - HO.psd

HO = Hot Operation: Excessive controller temp / fan protection

MagVFC - Fault - Lr.psd

Lr = Locked Rotor: Overloaded while PMA is running

2HP Pumps - Variable Speed Wide.psd

With variable speed conversion kits you can convert your existing fixed speed pump to variable speed. As an affordable upgrade, the conversion requires a minimal investment as it works with your existing system to increase flow as more fueling points go live, delivering the flow you need, as you need it.

In the Kit

The all-in-one upgrade kits inculde a variable speed pump motor assembly, MagVFC™, and a four-wire contractor’s plug.


Variable speed upgrade kits are compatible with both FE PETRO® brand 4" submersible turbine pumps as well as competitive pumps.

Easy Installation

Easy installation, consisting of swapping out the pump motor and controller, as well as modifying the submersible length and wiring if applicable.

Standard Features

  • Variable speed models are available in variable lengths only.
  • Check valve: 2¾" diameter fluorocarbon seal constructed with cast aluminum body and steel backing washer.
  • Pressure relief valve: available in four pressure relief settings, integral to check valve. Standard model relieves at 40 psi and resets above 35 psi.
  • Syphon: venturi-type syphon primer supplied with every submersible. Syphon check valve and secondary syphon sold separately.
  • Air eliminator: every submersible includes a tank return path with one-way check valve to provide active air elimination.
  • Electrical disconnect: electrical yoke for positive contractor disconnect during service.

Pump Motor

  • 2 hp or 4 hp, variable speed, two-stage centrifugal type pump motor with integral, automatic, thermal overload protection.
  • Max. flow: 2 hp = 110 gpm, 4 hp = 140 gpm.
  • Max. pressure: selectable operating pressure on MagVFC™ between 24 psi and 42 psi deadhead.
  • Available with MagShell™, which results in 45% increased flow area around motor.

Power Requirements - 60Hz & 50Hz

IST models can only be powered by a MagVFC™ or EcoVFC™ controller:

  • 2 hp models can operate with single phase incoming power supply to the MagVFC™.
  • 2 hp and 4 hp models operate with three-phase incoming power supply to the EcoVFC™.
  • Incoming power supply to the MagVFC™ can be 200-250 VAC, 50 Hz and 360-440 VAC, 50 Hz for the EcoVFC™.
  • MagVFC™ outputs a three-phase, variable frequency signal, valid for FE Petro variable speed pumps only.
  • 2 hp max. motor draw: 9 Amps.
  • 4 hp max. motor draw: 15 Amps.
  • MagVFC™ max. line draw: 20 Amps.

Liquid Compatibility

  • Max. liquid viscosity: 70 SSU at 60 °F (15 °C).
  • IST models imply alcohol-gasoline compatibility for fuel mixtures containing up to 85% ethanol, and 20% MTBE, 20% ETBE or 17% TAME with gasoline.
  • IST models can also be used with diesel fuels, fuel oils, kerosene, Avgas and jet fuels in a non-gelled pourable state.
  • All wetted elastomers are made of a high grade, fluorocarbon compound.


  • Consult factory for applicable approvals.
  • Franklin Fueling Systems is an ISO 9001 Certified Manufacturer.

Variable Frequency Controllers

Model Number Description
5874202800 MagVFC™, 2 Hp or 4 Hp Variable Frequency Controller, 220 V, one required per STP
5874202900 EcoVFC™, 2 Hp or 4 Hp Variable Frequency Controller, 380 V, one required per STP

Variable Speed Conversion Kits

Model Number Description
400693901 Kit with 2 Hp variable speed non-MagShell™ (PMA VS2)
402671901 Kit with 4 Hp variable speed non-MagShell™ (PMA VS4)

Variable Speed Conversion Kits - AG compatible

Model Number Description
400693905 MagVFC & variable speed conversion kit with AG compatible 2 Hp variable speed non-MagShell™
400693906 MagVFC & variable speed conversion kit with AG compatible 2 Hp variable speed with MagShell™
402671905 MagVFC & variable speed conversion kit with AG compatible 4 Hp variable speed non-MagShell™
402671906 MagVFC & variable speed conversion kit with AG compatible 4 Hp variable speed with MagShell™