Guardian VFD Pump Controller

Reduce maintenance and running costs while achieving optimum pump performance with our Guardian VFD Pump Controller.


The innovative design of our Guardian™ PC Pump Controller and Rod Pump Controller increases productivity and extends the life of new installations while also providing upgrades to existing installations. By deploying our Guardian PC Pump Controller, operators greatly reduce maintenance and running costs while providing optimum pump performance. Our Guardian PC Pump Controller and Rod Pump Controller come automatically integrated with each Guardian VFD, and no additional external hardware or interfaces are required except for an inexpensive arm position. Our VFD connects to a standard A/C motor and provides maximum well production and lower operational cost.

Guardian VFD

  • Guardian PC Pump Controller ensures operational efficiency and control of PC pump artificial lift systems
  • Guardian Rod Pump Controller protects rod string during high-torque conditions
  • Easy-to-use operator interfaces
  • Effortless integration into existing SCADA networks
  • Minimizes downtime using our integrated control methods and proprietary software suite
  • Simultaneously monitors pump performance and control pump-off

Control methods (GII Plus model)

  • Automatically changes speed of the pump to optimize well performance through remove-control methods
  • Set-up primary and secondary control methods to operate simultaneously
  • Downhole pressure sensors
  • Fluid over pump
  • High-torque control
  • Production flow
  • Flowline and casing pressure
  • Tank level

Guardian OnSite software

  • Retains central depository of information
  • Acquires real-time performance data
  • Maintains two-way communication between operator and pump

Standard configurations

  • Main-line circuit breaker
  • Lightning arrester
  • 5%-line reactor
  • Control transformer
  • Accessible terminal connections
  • Low maintenance


  • Restricts access based on user roles
  • Detailed change log tracks configuration changes and updates

Safety and performance

  • Simple and easy-to-use operator interfaces
  • Automatic, non-moving A/C motor tuning
  • cULu Listed enclosure
  • Local plotting of performance information
  • Safe access to data and diagnostic interface ports


  • Highest level of support and training at preferred locations


  • Versatile application and outstanding performance in the hardest conditions
  • Simple installation and start-up
  • User-friendly interface
  • Flowline and casing pressure inputs
  • Maximizes energy efficiency
  • Counterbalances weight adjustment reporting
  • Real-time position and torque display
  • Support for extreme climate conditions
  • Multispeed options for customizing up- and downstroke speeds
  • Automatic pump fill detection on each stroke
  • Belt slippage prevention and detection
  • Detailed fault history with real date timestamp
  • Energy meter reports kWh consumption
  • On/off timer control


  • Remote pump monitoring and control capabilities
  • Interactive communication between the operator and the well
  • Real-time well diagnostic and control functionality


  • Harmonic filters
  • Surface-pressure sensors (flowline/casing)
  • Downhole-pressure sensors and position sensors
  • Load cells and braking resistors
  • Communications (satellite/cellular/radio)
  • Running/fault lights
  • Power line-in/motor/Presco connectors
  • Motors: Totally enclosed fan-cooled (TEFC) or TEXP

Guardian VFD Pump Controller Ratings

Power Supply Voltage: 380–480 V (-15%/+10%)
Power Supply Frequency: 47–63 Hz
10 7.5 17.6
15 11 27.7
20 15 33
25 18.5 41
30 22 48
40 30 66
50 37 79
60 45 94
75 55 116
100 75 160
125 90 179
150 110 215

Guardian VFD Pump Controller Input/Output Configurations

  Standard + PLC Extended I/O
Basic Extended
Analog In 4   2
Analog Out 3   2
Digital In 16 4 4
Digital Out 6 2 2
Relay Out 2 1 1

Guardian VFD Pump Controller Communications

Modbus 1 (RS422/RS485)
TCP/IP (Optional) 1
CanOpen (Optional) 1
Ethernet (Optional) 1
Bluetooth (Optional) 1

Guardian VFD Pump Controller Protections (Internal to the VFD)

Thermal protection Yes, 12-ton motor thermal protection  depending on the thermal-protection motor frequency
Memorization when power off
Electronic/PTC Yes, dedicated input on option cards
Short circuit between phases Yes
Ground fault Yes
Output phase loss Yes
Input phase loss Yes
Overload Yes
Overvoltage Yes
Undervoltage Yes
Drive thermal protection Yes
Locked motor protection Yes
Stall prevention Yes
  • NOV Guardian Variable Frequency Drive (VFD) PC Pump Controller & Optimization System Flyer

  • Guardian Automation and Control for Rod Pump Controller Flyer

Render of Guardian VFD Rod Pump Controller