EP-250W Heavy-Duty Output DC Motor
For many general-purpose industrial applications — conveyor main drives, pump sets, stirrer mechanisms, and feeder drives — the brushed 250W architecture offers a compelling balance: the inherent torque-speed curve of a permanent magnet dc motor, combined with straightforward PWM speed control from a standard dc motor drive controller.
The K6D frame that underpins this motor is notably more robust than the K5D used in the 40–120W range. The housing diameter steps up to 120 mm, flange to 104×104 mm, and the mounting bolt pattern uses M8 fasteners (or 4×ø9 through holes), providing the structural rigidity needed to react gearbox side-loads and output shaft radial forces in continuous-duty applications. Motor body length is 167.5 mm ±1 mm, with a motor lead cable pre-fitted at 300 mm — sufficient for panel routing in most standard enclosure layouts.
EP Series | 250W Heavy-Duty Output
EP-250W DC Motor
When standard fractional-horsepower drives no longer cut it, the EP-250W steps in. This heavy-duty brushed dc motor delivers a consistent 250W output across three voltage configurations — 24V, 90V, and 220V — with a rated load speed of 3,000 RPM and a peak output torque reaching 796 kg·cm. Built on the K6D frame with a 104×104 mm face-mount flange and a 120 mm diameter housing, it is the go-to choice for machine builders who need a reliable, controllable high torque dc motor without committing to the complexity and cost of a three-phase AC inverter system. Available with a gear shaft, flat type, or milled keyway output shaft, the EP-250W integrates directly with the 6GU gearbox series for complete electromechanical drive solutions across demanding industrial, agricultural, and process-automation environments worldwide.
Motor Performance Parameters
All figures below are measured under standard ambient test conditions (20°C, sea level). The □ suffix denotes the output shaft type — refer to the bare motor output shaft dimension table for gear shaft, flat type, and milled keyway configurations. Motor voltage, power, and speed can be customised within the allowable frame dimensions on confirmed orders.
| Model | Voltage (V) | Power (W) | No-load | Full Load | Brush Life (H) | Weight (kg) | |||
|---|---|---|---|---|---|---|---|---|---|
| Speed (RPM) | Current (A) Max | Speed (RPM) | Torque (kg·cm) | Current (A) | |||||
| K6D250-24□ | 24 | 250 | 3400 | 3.0 Max | 3000 | 796 | 16.0 | 2000 | 3.2 |
| K6D250-90□ | 90 | 250 | 3300 | 1.2 Max | 3000 | 796 | 4.0 | 2000 | 3.2 |
| K6D250-220□ | 220 | 250 | 3300 | 0.9 Max | 3000 | 796 | 2.0 | 2000 | 3.2 |
Note: Motor voltage, power, and speed can be customised to customer specifications within the allowable frame dimensions.
Compatible Gearbox Dimensions — 6GU Series
The 6GU gearbox series mounts directly to the EP-250W's 104×104 mm flange via four M8 bolts (or 4×ø9 through holes). The L dimension is the gearbox body length exclusive of the motor; combined drive length equals L + 42 mm + motor body length. The motor-only weight is 3.2 kg; combined weights are listed below.
| Gearbox Model | L Dimension (mm) | Gearbox Weight (kg) |
|---|---|---|
| 6GU3K – GU9K | 72 | 1.87 |
| 6GU10K – GU18K | 72 | 2.10 |
| 6GU20K – GU200K | 72 | 2.75 |
| Motor (bare) | — | 5.68 (with gearbox) |
Allowable Torque on Gearbox — K6D250-24GU
The torque values below apply when the K6D250-24GU motor is paired with the compatible 6GU gearbox series. Always confirm that the required application output torque falls below the allowable torque at the selected reduction ratio before finalising your drive specification. Torque is given in both N·m and kgf·cm for international engineering reference.
| Type | Parameter | 3 | 3.6 | 5 | 6 | 7.5 | 9 | 12.5 | 15 | 18 | 25 | 30 | 36 | 50 | 60 | 75 | 90 | 100 | 120 | 150 | 180 | 200 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| K6D250-24GU | Speed (r/min) | 1000 | 833 | 600 | 500 | 400 | 333 | 240 | 200 | 166 | 120 | 100 | 83 | 60 | 50 | 40 | 33 | 30 | 25 | 20 | 16 | 15 |
| Torque (N·m) | 1.93 | 2.32 | 3.22 | 3.86 | 4.83 | 5.80 | 7.20 | 8.70 | 10.4 | 13.1 | 15.7 | 18.9 | 26.2 | 31.5 | 40.0 | 40.0 | 40.0 | 40.0 | 40.0 | 40.0 | 40.0 | |
| Torque (kgf·cm) | 19.7 | 23.6 | 32.8 | 39.4 | 49.3 | 59.2 | 74.1 | 88.9 | 106 | 133 | 160 | 192 | 267 | 400 | 400 | 400 | 400 | 400 | 400 | 400 | 400 |
Bare Motor Output Shaft Options
| Shaft Type | Gear Shaft | Flat Type | Milled Keyway |
|---|---|---|---|
| Model Code | DC6GU□ | DC6A□ | DC6A1□ |
| Typical Application | Gearbox direct mount | Pulley / sheave drive | Keyed coupling / sprocket |
Five Key Advantages of the EP-250W DC Motor
① True 250W Continuous Output
Unlike motors rated at peak or intermittent figures, the EP-250W is specified at continuous 250W output — the value that matters in real production environments. With a rated load torque of 796 kg·cm at 3,000 RPM, this high torque electric motor handles sustained drive duties without thermal derating, making it dependable across multi-shift production schedules in facilities from the UK to South Korea.
② Three Voltage Options — 24V, 90V, 220V
The EP-250W range spans three supply voltages, covering 24V mobile and vehicle electrical systems, the 90V regulated DC bus common in North American and European industrial plant, and 220V supplies for direct mains-connected applications. This breadth eliminates the need for voltage conversion hardware across different market regions, simplifying BOM management for multinational OEM programmes.
③ Customisable Voltage, Power & Speed
Standard motor voltage, power rating, and no-load speed can all be adjusted to customer specifications within the allowable frame dimensions — a capability that distinguishes purpose-built factory production from catalogue-only supply. This makes the EP-250W a practical basis for custom drive units in specialised agricultural machinery, process equipment, and test-rig applications where standard catalogue ratings do not align precisely with load requirements.
④ Direct 6GU Gearbox Compatibility
The 104×104 mm flange and standardised output shaft options mate directly with the 6GU gearbox series, covering reduction ratios from 3:1 to 200:1 with allowable output torques up to 400 N·m at high ratios. This direct interface eliminates adaptor plates and reduces combined assembly length, keeping the motor-gearbox package compact enough for enclosed machine bases and tight equipment footprints in automated production lines.
⑤ ISO 9001:2015 Verified Quality
Every EP-250W unit exits the production line with a completed functional test record covering no-load speed, rated-load current draw, winding insulation resistance, and commutation quality. This traceability supports CE marking and UKCA compliance documentation for European and British market entries, and meets the material disclosure requirements for Australian industrial equipment registers and North American safety certification bodies.
DC Motor Working Principle
The dc motor working principle that drives the EP-250W is the same electromagnetic law at work in every brushed permanent magnet motor: a conductor carrying direct current through a magnetic field experiences a mechanical force proportional to the field strength, the current magnitude, and the conductor length. In practice, the wound armature coils carry this current while the surrounding permanent magnets in the stator housing provide the static field. The result is a tangential force on every active conductor in the armature — summed across all winding slots, this produces the continuous rotational torque measured at the output shaft.
The mechanical commutator — a precision-ground segmented copper ring — switches current direction through each winding group in exact synchrony with rotor angular position. This self-commutating action distinguishes the brushed dc motor from a brushless dc motor or bldc motor, which requires an external electronic drive stage and rotor position sensing to perform the same function electronically. At the 250W power level, the cost of the brushed motor plus a standard dc motor drive controller is typically lower than an equivalent bldc motor system with its three-phase inverter, position sensor, and wiring harness — a practical consideration that keeps brushed motors relevant in new machine designs well beyond what their age as a technology might suggest.
Back-EMF regulation provides the inherent speed-stabilising characteristic that makes the EP-250W well suited to variable-load applications. As the armature accelerates, it generates a counter-voltage that limits further speed increase. A rising mechanical load reduces back-EMF, allowing greater current to flow and torque to increase automatically — without requiring a separate feedback controller for many standard conveyor or pump applications. For tighter speed regulation, a simple tachometer-feedback dc motor drive closes the loop with minimal additional electronics.
Compared to a dc servo motor, the EP-250W does not incorporate an integrated position encoder or resolver, so it does not offer the precise position control of a full servo axis. Compared to a dc stepper motor, it produces smooth continuous rotation rather than discrete angular steps, making it far better suited to constant-speed drive tasks at this power level. The question of what type of dc motor fits a given application usually resolves to: how much position precision is required, and how much drive controller cost is acceptable? For speed-controlled drives in the 250W bracket, the brushed permanent magnet dc motor remains a practical and cost-efficient answer to both questions.
Materials & Build Quality
At 250W continuous output, thermal management and structural rigidity become critical design considerations. The EP-250W housing is a cold-rolled steel structure, powder-coated for corrosion resistance and dimensionally stable under the higher winding temperatures generated at this power level. The 120 mm housing diameter allows a larger stator bore compared to the 90 mm frames used in the lower-power EP series, accommodating the higher-energy permanent magnets required to produce the motor's 796 kg·cm rated load torque at a practical armature current.
The stator magnets are high-coercivity sintered permanent magnets selected for stable flux density up to 90°C continuous winding temperature. Below this threshold — which the EP-250W comfortably maintains at rated load in standard workshop ambient conditions — flux loss is negligible over the motor's service life. The armature core uses grain-oriented silicon steel laminations with interlayer insulation varnish, cutting eddy-current losses at the 3,000–3,400 RPM operating band and keeping winding temperature rise within the Class B (130°C) enamelled copper wire's rated limit.
The commutator is CNC-ground copper with a surface finish maintained to tight concentricity tolerances, ensuring even carbon brush contact pressure across the full operating speed range. Brush holders are spring-loaded for consistent contact force as brushes wear, extending the consistent commutation quality that underpins the 2,000-hour rated brush life. While this is shorter than the 3,000-hour rating of the smaller EP series motors — a natural consequence of the higher current density at 250W — it remains a practical service interval for quarterly maintenance schedules in most industrial applications.
Ball bearings at both shaft ends are pre-greased, sealed deep-groove types specified for the higher radial loads characteristic of this frame size, particularly in gearbox-mounted configurations where output shaft side-loads are transmitted back through the motor bearing. All materials are RoHS 2 compliant, supporting CE and UKCA marking for European and British market equipment certification.
Scenariusze zastosowań
At 250W, the EP motor series moves into territory where it competes directly with small AC motor and inverter combinations. For speed-controlled DC drives where supply simplicity and dynamic torque response matter more than peak energy efficiency, the following sectors consistently specify brushed dc electric motors in this power band.
🏭 Industrial Conveyor Main Drives
Main drive motors on light-to-medium conveyor systems — product assembly lines, sortation belts, and pallet transfer units — regularly operate in the 200–300W bracket. The EP-250W at 24V powers 12V/24V DC bus conveyor systems common in North American logistics facilities, while the 90V variant serves European regulated DC bus installations. Variable speed control via PWM drive gives immediate speed response on start/stop cycles without the current surge of a direct-on-line AC motor.
🌾 Agricultural Feed & Processing Equipment
Grain auger main drives, silage cutter motors, and mixer-feeder drive heads on Australian and South American farms need robust drives that operate reliably from tractor PTO-charged battery banks or generator sets. The 24V K6D250-24□ variant works directly from a 24V agricultural electrical system, delivering the shaft power to handle variable grain density loads without stalling — a scenario where the permanent magnet dc motor's back-EMF self-regulation provides a natural torque boost at low speed under heavy load.
⚙️ Pump & Compressor Drives
Hydraulic power unit main pumps, cooling water circulator pumps, and vacuum system compressor drives in UK and European manufacturing facilities use 250W DC motors where variable flow rate control matters. A brushed dc motor drive with tachometer feedback on the EP-250W achieves ±1% speed regulation at rated load — adequate for most process-cooling and hydraulic pressure maintenance applications without the added investment of a full closed-loop servo axis.
🔬 Test Bench & Dynamometer Rigs
Load simulation platforms and torque calibration benches in South Korean and Japanese research facilities frequently use a 250W motor as a controllable load source or as the prime mover in endurance testing rigs. The EP-250W's availability at 220V makes it straightforward to connect directly to the single-phase supply used in many laboratory environments, eliminating the step-down transformer typically needed for 90V motor operation.
🚛 Material Handling & Hoist Drives
Small goods hoists, cable winches, and winding drum drives in Dutch and Belgian warehouse environments are a natural fit for the EP-250W paired with a high-ratio 6GU gearbox. A 200:1 reduction brings the 3,000 RPM motor output down to 15 r/min at the drum — slow enough for controlled lifting — while the 40 N·m gearbox allowable torque at this ratio safely handles the peak cable tension on typical light-goods hoist duty cycles.
🖥️ Automation & Robotic Sub-Drives
Collaborative robot base rotation axes, automated guided vehicle (AGV) drive wheels, and large CNC rotary table drives use 250W-class brushed motors as a cost-effective alternative to brushless servo systems on axes where positioning accuracy of ±0.5° or better is not required. For Canadian and Australian machine builders designing custom automation cells, the EP-250W combined with an optical encoder and a DC servo controller offers adequate motion control performance at a fraction of the cost of a dedicated dc servo motor and amplifier package.
About Our Production Facility
With over ten years building mechanical power transmission components for global markets, our production facility brings in-house expertise across the full drive chain — from wound armature assemblies and commutator grinding through gear hobbing, shaft turning, and gearbox assembly. This vertical integration is the reason we can offer customised motor voltage, power, and speed configurations on the EP-250W: the engineering knowledge to modify winding parameters and verify the result sits inside the same building as the production line, not distributed across a network of subcontractors.
Our product portfolio extends across agricultural gearboxes, worm gear reducers, planetary gear drives, power take-off shafts, hydraulic cylinders, transmission chains, and a full series of dc electric motors. The facility operates under ISO 9001:2015 quality management certification, with documented control of incoming materials, in-process inspection, and end-of-line functional testing. Mechanical assemblies and gearboxes are produced in ductile iron, cast iron, cast steel, precision cast steel, and cast aluminium; we also manufacture gears, sprockets, worm gears, pulleys, worm shafts, and standard as well as non-standard transmission parts to customer drawing.
Every EP-250W dc motor is accompanied by a traceable functional test record, and full documentation packages — including dimensional drawings, material compliance declarations, and performance test reports — are available to support customer certification and compliance processes across the UK, EU, Australia, Canada, and other major markets.
Warsztat
Complementary Products — One-Stop Drive System Supply
The EP-250W dc motor is most effective as part of an integrated drive system. Our facility produces the complete range of compatible drive and reduction components, allowing customers to source motor, gearbox, and associated drive elements from a single point of contact — simplifying procurement, reducing cross-supplier engineering risk, and streamlining after-sales support across our international customer base.
Our full Silniki elektryczne catalogue spans AC induction, three-phase, single-phase, and multiple DC motor types across a wide power range. Machine builders who need different drive outputs for different axes of a single machine can source AC and DC motor types with consistent flange standards and shared engineering documentation — a real advantage when commissioning multi-axis systems for European or North American markets where documentation compliance is tightly audited.
Our Przekładnia ślimakowa series pairs naturally with the EP-250W where right-angle drive and self-locking output is required. Reduction ratios from 5:1 to 100:1, combined with the EP-250W's continuous 250W output, produce an output torque envelope well beyond what the motor achieves bare — and the self-locking characteristic of the worm stage holds load position when power is removed, without needing a separate mechanical brake on hoist, gate, or valve actuator applications.
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