Permanent Magnet Motor Selection Parameters, Organised by Industry
Consolidated power, voltage, speed, torque, efficiency and power-factor ranges for the permanent magnet motor families MotiraTech works with, mapped to the industries and machines where each family is normally applied.
Manufacturer selection data, not project results
Every figure below is taken from manufacturer selection documentation for the permanent magnet motor families MotiraTech integrates. They describe what can be supplied — not what has been measured at any particular site. Final ratings, protection class, cooling arrangement and drive matching are confirmed by engineering review against site data before any recommendation is made.
Which motor family applies where
Machine duty, supply voltage and hazardous-area classification decide the family before any rating is selected.
Underground and overland belt conveyors, ball mills, flotation machines, cooling tower fans, hoists and winches.
- —Permanent magnet motorized pulleys with explosion-proof 1 140 V drive cabinets for underground conveying
- —Low-speed high-torque direct drive, 3.3–10 kV, for mill and flotation duty
- —Medium-voltage variable-speed motors for fans and pumps
Mill feed and clinker conveyors, separators, ball and vertical mills, process and cooling fans.
- —Permanent magnet motorized pulleys, low-voltage drive cabinets
- —Medium-voltage variable-speed motors, 6 kV / 10 kV, for mill and fan duty
- —Line-start medium-voltage motors where the drive runs at fixed speed
Yard and overland conveyors, transfer towers, bucket elevators, stackers, reclaimers and shiploaders.
- —Permanent magnet motorized pulleys, 380 V to 10 kV
- —Low-speed high-torque direct drive for head-shaft and slew duty
- —Matched variable-frequency drive cabinets, 380 / 660 V
Chip and bark conveyors, pulpers, refiners, stock and vacuum pumps, fans.
- —Low-voltage variable-speed permanent magnet motors, 1.1–315 kW
- —Line-start low-voltage motors on constant-speed pump and fan duty
- —Permanent magnet motorized pulleys on wood-yard conveying
Top drives, drawworks, mud pumps, rotary tables, workover rigs, fracturing skids and artificial lift.
- —Low-voltage variable-speed permanent magnet motors on skid-mounted and mobile equipment
- —Medium-voltage variable-speed motors for high-power pump duty
- —Low-speed high-torque direct drive on rotary and lift applications
Motor families and rated parameters
Ranges cover the published selection tables. Individual models within each family carry their own rated current, torque, efficiency and starting multipliers, which are quoted per selection.
Line-start permanent magnet synchronous motor — low voltage
Direct-on-line replacement for standard induction motors on fluid-type loads (fans, pumps, compressors, air-cooled condenser fans) where no variable-frequency drive is installed.
| 01Rated power range | 0.75 – 900kW |
|---|---|
| 02Supply voltage | 380V |
| 03Pole numbers | 2 / 4 / 6 / 8 / 10 poles |
| 04Synchronous speed | 600 – 3 000r/min |
| 05Frame sizes | 90 – 450 |
| 06Rated efficiency | up to 96.4%Series-dependent; lower ratings sit well below the top of the range. |
| 07Rated power factor | ≥ 0.96 |
| 08Pull-out torque multiplier | 1.6 × |
| 09Locked-rotor torque multiplier | 1.2 – 2.2 × |
| 10Locked-rotor current multiplier | 9 ×Starting current must be checked against supply capacity and protection settings. |
Line-start permanent magnet synchronous motor — medium voltage
Large fixed-speed plant drives on 6 kV and 10 kV distribution: mill and fan duty where the machine runs at essentially constant speed.
| 01Rated power range | 185 – 5 000kW |
|---|---|
| 02Supply voltage | 6 000 / 10 000V |
| 03Pole numbers | 4 / 6 / 8 / 10 / 12 poles |
| 04Synchronous speed | 500 – 1 500r/min |
| 05Frame sizes | 355 – 1 000 |
| 06Rated efficiency | 94.2 – 97.4% |
| 07Rated power factor | ≥ 0.96 |
| 08Pull-out torque multiplier | 1.6 × |
| 09Locked-rotor current multiplier | 9 – 9.5 × |
Variable-speed permanent magnet synchronous motor — low voltage
Matched motor and variable-frequency drive for process loads with speed regulation: process pumps, pulpers, feeders, extruders and machinery drives.
| 01Rated power range | 1.1 – 315kW |
|---|---|
| 02Supply voltage | 380V |
| 03Rated speed | 600 – 3 000r/min |
| 04Frame sizes | 90 – 355 |
| 05Rated efficiency | up to ≈ 96% |
| 06Rated power factor | ≥ 0.96 |
| 07Drive requirement | Matched variable-frequency driveA permanent magnet motor cannot be run on an arbitrary induction-motor VFD without parameter matching. |
Variable-speed permanent magnet synchronous motor — medium voltage
Medium-voltage variable-speed duty for mills, large fans and pumps where flow or load varies through the process cycle.
| 01Rated power range | 185 – 5 000kW |
|---|---|
| 02Supply voltage | 6 000 / 10 000V |
| 03Rated speed | 500 – 1 500r/min |
| 04Frame sizes | 355 – 1 000 |
| 05Rated efficiency | up to ≈ 97.3% |
| 06Rated power factor | ≥ 0.96 |
Low-speed high-torque permanent magnet direct drive motor
Gearless drive wound for the driven speed, used on ball mills, flotation machines, large conveyor head shafts and similar low-speed, high-torque machines. Explosion-proof and non-explosion-proof variants exist.
| 01Rated power range | 400 – 1 250kWSelection table extract; the wider family covers additional ratings. |
|---|---|
| 02Rated torque range | 42 444 – 132 639N·m |
| 03Rated speed | 60 / 80 / 90r/min |
| 04Supply voltage | 3 300 / 6 000 / 10 000V |
| 05Frame sizes | 800 – 1 120 |
| 06Rated efficiency | 95 – 96% |
| 07Rated power factor | 0.96 – 0.97 |
| 08Rated frequency | 45 – 60Hz |
| 09Maximum torque multiplier | 2 × |
Permanent magnet motorized pulley and drive system
Motor integrated into the conveyor drum with a matched drive cabinet, removing the external motor, gearbox, coupling and base frame.
| 01Cabinet voltage classes | 380 / 660 / 1 140V |
|---|---|
| 02Non-explosion-proof types | F1 / F2380 V applies to non-explosion-proof F1 and F2 types only. |
| 03Explosion-proof type | Type B1 140 V applies to the explosion-proof type; the cabinet is supplied as an explosion-proof enclosure. |
| 04Rating basis | General load and heavy load ratings quoted separately |
| 05Motor-to-drive distance | > 300 m explosion-proof / > 200 m non-explosion-proofAbove these distances the selection changes; cable and communication design must be reviewed. |
| 06Communication distance note | > 50 m treated as a separate selection condition |
What MotiraTech needs to make a selection
| 01Machine and duty | Type, throughput, run hours, start pattern under load |
|---|---|
| 02Existing drivetrain | Motor nameplate, gearbox ratio, coupling, fault history |
| 03Torque and power | Rated and breakaway torque; measured absorbed power where available |
| 04Speed requirement | Fixed speed or regulated range, and control source |
| 05Electrical supply | 380 V / 660 V / 1 140 V / 3.3 kV / 6 kV / 10 kV, capacity and starting method |
| 06Area classification | Explosion-proof requirement, ingress and ambient conditions |
| 07Envelope and access | Available space at the drive head, crane access, outage window |
Send the machine data — we return a selection, not a brochure
Provide nameplate and duty data for the machine in question and MotiraTech will review whether a permanent magnet family applies, and what would need to be verified on site.