Conveyor motor speed controller (AC speed control unit, DC SCR control and cabinet drive package)

01

Match the speed controller to the conveyor motor

The controller follows the motor. For small AC speed-control gearmotors, Yueqing Winston Electric lists its SS-22 speed control unit for motors of 6, 15, 25, 40, 60, 90 and 120 W on a 220 V AC 50/60 Hz supply (±10%), with a speed range of 90–1400 r/min at 50 Hz and 90–2800 r/min at 60 Hz, an operating temperature of –10 °C to +50 °C and a body of 57 × 40 × 78 mm; forward or reverse running is chosen by how the CW, CCW and COM terminals are connected. [1]

Editorial calculation: scaling 1400 r/min by 60/50 gives 1680 r/min, not 2800 r/min, so the listed 60 Hz upper speed should be confirmed with the supplier for the motor you will use. [1]

For brush DC gearmotors, Dart Controls lists its 125DV200E as a cast aluminium NEMA 4X enclosed DC SCR control for motors up to 2 HP, taking 120 or 240 V AC in and giving 0–90 or 0–180 V DC out, for a range of 1/4 to 2 HP. Variants add forward/stop/reverse, run/jog, or an auto/manual follower that takes a voltage or 4–20 mA signal, so a line controller can set conveyor speed. [3] Editorial calculation: 2 HP × 0.746 = 1.49 kW and 1/4 HP = 0.19 kW.

Give the supplier the conveyor type, load and speed range, the motor type (AC speed-control, three-phase induction or brush DC), its power, voltage and gear ratio, the supply voltage, the control signal (potentiometer, 0–10 V, 4–20 mA or fieldbus), reversing and jog needs, starting and stopping ramps, the enclosure rating and ambient temperature, and whether the controller is to be supplied loose or built into a cabinet.

02

Fit out an inverter drive cabinet for a conveyor line

Where conveyors are driven by three-phase motors, the controller is an inverter. Winston lists its WST700 series for 400 V or 230 V input (±15%) at 47–63 Hz, with output frequency 0–400 Hz, V/F or sensorless vector control, and overload capacity of 150% of rated current for 60 s and 180% for 10 s. [2]

Cabinet builds add a line reactor ahead of the drive. MTE states that its RL line/load reactors reduce nuisance tripping, lower harmonic distortion and minimise long-lead effects, and lists them for 4- or 6-pulse rectifiers in currents from 1 A to 1,500 A, impedances of 1.5%, 3% and 5%, 208–690 V, 50/60 Hz, an ambient range of –40 °C to 50 °C and altitude to 1,000 m without derating. Overload is rated at 200% for 30 minutes and 300% for 1 minute, and the continuous service factor is 150% of rating for reactors up to 750 A and 125% above. [4]

Editorial calculation: the drive's 180% for 10 s is below the reactor's 300% for 1 minute, so on the published figures the reactor's short-time rating, relative to its own rated current, is higher than the drive's. [2] [4] Ask the cabinet builder which impedance was chosen and why.

03

Compare the three controller types

The published examples differ in motor, power and control. Figures are as listed by each maker.

04

Power module, control board, reactor and disconnect

05

Power, supply, overload and control-signal data to quote

06

Send the conveyor, motor and control data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Conveyor: [type; load; speed range]
Motor: [AC speed-control, three-phase or brush DC; power; voltage; gear ratio]
Supply: [voltage; phases; frequency]
Control: [pot, 0–10 V, 4–20 mA or fieldbus; reversing; jog; ramps]
Cabinet: [loose or built in; line reactor impedance; disconnect; enclosure rating]
Environment: [ambient temperature; washdown]

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