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Variable Frequency Drive Triol AT24 line SR

Variable Frequency Drive Triol AT24 line SR  is specially designed for high technological tasks of controlling sucker rod pumps (SRP) with induction motors. Implementing of Triol AT24 VFD line SR there is no need to use a rod load sensor, thanks to Triol special algorithms, which allow getting dynamograms with a measurement error of less than 2%.

There is no need to use braking resistors due to drive automatic adaptation to the rod pumping speed. Rocking mill balancing control system and rocking mill mechanical part diagnostic system allows monitoring system status and perform maintenance in time.

Automatic flow rate optimization makes it easy to maintain the rate at the optimal level by controlling the well dynamics. It is possible to optimize the process due to archives of dynamograms. The archived data is accessible over the years, whenever you need it.

Safe operation of Triol AT24 VFD line SR is ensured by blocking from unauthorized pump start and change of system key settings, as well as light and sound alerts for personnel before operation start.

Remote monitoring and control via GSM-modem compatible with any application makes it easy and convenient for maintenance personnel. It is possible to control the drive via satellite communication as well.

Distinctive benefits of Variable Frequency Drive Triol AT24 line SR:

  • Investment savings
  • Cost saving
  • Motors lifetime extension
  • IP55 (NEMA3R) / optional NEMA4/IP65
  • operating temperature -40 ºC…+50 ºC (-40…+122 F)
  • removable graphic terminal with induction supply or SRP controller
  • built-in input circuit breaker
  • three-phase socket (optional), placed in a single cabinet of hinged design
  • remote control terminal with transient graphs
  • settings via smartphone
  • service software


Input voltage, V3х380 / 3х480/ 3×690 (-15 % …+10 %)
Input frequency, Hz50 / 60 (-5 %…+5 %)


Output current, A8.8 … 150
Output frequency, Hz0.5…400
Frequency resolution, Hz0.1
Acceleration / deceleration time, s1 …4000
Overcurrent characteristics150 % of rated value for 60 sec
Efficiency, %>97

Motor control

Control methodsV/f (volts-per-hertz) (5 reference point) sensorless vector control (open-loop) sensor vector control (close-loop)
PWM frequency, kHz2…10
Speed range1:100 in open-loop system 1:1000 in closed-loop system
Speed accuracy (static)±10% of motor nominal slip in open-loop system ±0.1 % of rated speed in close-loop system
Torque accuracy±10% in open-loop system ± 5 % in close-loop system
BrakingBy frequency



Acceleration / deceleration typesS-curve, linear (3 reference points)



Removable graphic terminal with induction power / SRP controller with 3.5″ or 7″ touchscreen

Light alarm“Ready”; “Run”;” Fault”, “Control channel”
Push buttons“Start”; “Stop”; “Program”, navigation keys

Control signals

Customer supply10 V DC, up to 30 mA 24 V DC, up to 150 mA
Number of discrete inputs8
Discrete inputsprogrammable
Discrete inputs type24 V
Number of relay outputs4
Relay outputs type250 V, 1 A
Number of analog inputs2, open collector
Analog inputsProgrammable 0…10 V / 0…5 mA / 4…20 mA
Number of analog outputs1
Analog outputsProgrammable 0…10 V / 0…5 mA / 4…20 mA


Physical Interface2 wire RS-485 for Modbus
Communication protocolsModbus RTU
Frame transmission115200 bps by default 1200 -250000 bps
Data format8 bits, 1 stop bit, no parity
Number of addresses1…255 for Modbus


Supply protectionsPhase loss, phase sequence fault
Motor protectionsOvercurrent



Phase loss

Current unbalance

Encoder open circuit

Brake resistor open circuit

VFD protectionsOverload, Overheating, DC-link undervoltage, DC-link overvoltage, Power switch failure
Protections provided SRP controllerGearbox torque limit

Limiting the effects of gas

Limiting the minimum load on the bar

Limit the maximum load on the bar

Restriction of the minimum and maximum filling of the pump

InsulationGalvanic isolation between power and user circuits
Insulation resistance>1 MQ


Circuit breakerBuilt-in
DC-linkUp to 11 kW: option, built-in From 15 kW: built-in
Braking IGBT- chopperUp to 11 kW: built-in From 15 kW: option, built-in
Input EMC filter (C2)Option, built-in
GSM / GPRS wireless routerOption, built-in

Optional equipment

Input passive harmonic filterOption, outdoor
Braking resistorsOption, outdoor
Output sine filterOption, outdoor


Cabinet materialSteel
CoolingForced air
Noise level, @ 1 m, dB(A)<75
InstallationFloor mounting
Cable entryBottom

Operating conditions

Operating conditionsOutdoor
Operating temperature-40…+50 °C (-40…+122 F)
Storage temperature-50…+60 °C (-50…+140 F)
Relative humidity, %from 5 to 90 non condensing
Altitude, mup to 1000 m – rated power above 1000 m – with reduced power
  • Start / stop / reverse of motor with set acceleration and deceleration rates
  • Motor speed and torque control
  • Auto-tuning of motor parameters (with rotation and without)
  • PID-controller
  • Automatic restart
  • “Catch on the fly” mode
  • Motor group control
  • Operation by calendar
  • Energy and electricity meters
  • Encoders supported – incremental, absolute, sine/cosine
  • Accelerated passing of resonant  frequencies (3 ranges)
  • Recording the last 32 reasons of failures