Hydraulic Power

Published 12 V and 24 V Hydraulic Power Unit Motor Data

The following values come from Sunroad Motor's published hydraulic power unit motor catalog. They are reference ratings for initial comparison, not a substitute for the approved drawing, pump load, cable sizing, protection design or sample validation. Ingress protection is not shown in these tables because it varies by model and must be confirmed for the selected construction.

Published 12 V DC models

Published 24 V DC models

How Pressure and Flow Affect Motor Selection

Motor selection starts with the hydraulic work required from the pump. A useful first estimate is hydraulic output power in kW = pressure in bar x flow in L/min / 600. The DC motor must provide more input than this hydraulic output because pump, motor, cable, contactor and control losses reduce total efficiency. The calculation is only a starting point; the final working point must be checked against the pump curve and motor test data.

Peak pressure, relief-valve operation and cold-oil starts can demand more torque and current than a nominal steady point. State the maximum pressure, target flow, oil viscosity and lowest starting temperature instead of selecting from rated motor watts alone.

Choosing Between 12 V and 24 V

Use the equipment's approved DC architecture. For comparable output, a 24 V design will usually require less current than a 12 V design, which can reduce voltage drop and the burden on cables, terminals and switching devices. This does not make 24 V automatically interchangeable with 12 V. The battery, charger, contactor, controller, wiring and protection system must all match the selected voltage and real starting current.

For a deeper 12 V selection workflow, read How to Select a 12 V Hydraulic DC Motor for an OEM Power Unit.

Duty Cycle and Thermal Validation

Every published model in the tables above uses S2 short-time duty. S2 2 min, for example, describes a short operating period under defined test conditions followed by enough rest for the motor to return toward ambient temperature. It does not mean two minutes on and an arbitrary short pause off, and it does not approve continuous S1 operation.

Provide the longest run, starts per hour, load profile, cooling interval, ambient temperature and surrounding enclosure. A sample should then be tested in the real hydraulic circuit or a representative bench setup. Record motor-terminal voltage, current, speed, pressure, flow and temperature through the complete operating sequence.

Mechanical and Electrical Interface Review

Pump-side mechanical data

• Mounting face, pilot diameter, bolt pattern and available envelope.
• Shaft diameter, extension, key or spline, coupling and rotation direction.
• Permitted axial and radial shaft loads, alignment and sealing arrangement.

Vehicle or equipment electrical data

• Nominal voltage, minimum voltage during cranking and cable length.
• Terminal style, cable size, contactor or controller and fuse strategy.
• Thermal protection, temperature sensing, grounding and EMC requirements.

Shaft, flange, rotation, terminal and protection options must be reviewed as project-specific configurations. A similar catalog model does not prove drop-in interchangeability.

Typical Hydraulic Power Unit Applications

Published Sunroad catalog applications include hydraulic forklifts, stackers, auto hoists, lifting platforms and vehicle tail-lift systems. The common requirement is short, high-current operation that turns a hydraulic pump. The motor should not be presented as a complete pump or complete hydraulic power unit unless the quoted scope explicitly includes those components.

OEM Project Evaluation Process

1. Requirement review: confirm pressure, flow, voltage, duty, environment, interface and compliance inputs.
2. Reference selection: compare a catalog model or existing motor sample, then identify electrical and mechanical differences.
3. Prototype validation: test starting, loaded operation, temperature rise, commutation, protection and fit in the intended system.
4. Specification freeze: approve the drawing, performance limits, materials or critical components, labeling, inspection plan and change-control route before production.

Other motor families and application categories are available through the DC motor product hub.

RFQ Checklist for a Hydraulic Power Unit DC Motor

• Application and whether the request is for the motor only or a complete power unit.
• 12 V or 24 V supply, battery condition and allowable voltage drop.
• Pump displacement, required flow, normal pressure and maximum pressure.
• Run time, starts per hour, rest interval and complete load sequence.
• Mounting, shaft, rotation, coupling and dimensional drawing.
• Ambient temperature, oil temperature, contamination and sealing requirements.
• Terminals, cables, contactor or controller, protection and sensing.
• Prototype quantity, annual quantity, target schedule and destination market.
• Required tests, standards, reports, labels and traceability.
• Existing motor sample, pump curve and known failure or improvement target.

Frequently Asked Questions

Is this a hydraulic motor?

No. It is a DC electric motor that drives a hydraulic pump. The pump and hydraulic circuit create flow and pressure.

Can a catalog motor run continuously?

Do not assume so. The published models on this page are rated for S2 short-time duty. Continuous or repeated operation needs a separate thermal and performance review.

Can a 12 V motor be replaced directly by a 24 V motor?

No. Voltage changes affect the complete electrical system, including battery, charger, contactor, controller, cable, fuse and protection design.

How is the first reference model selected?

Start with pressure, flow, pump displacement, voltage and duty. Then compare speed, torque, current, mounting, shaft, rotation, enclosure and protection requirements.

Does one published ingress-protection rating apply to every version?

No. Ingress protection depends on the exact model and construction. Confirm it on the approved drawing or specification for the quoted version.

Prepare a project review: send the checklist, pump data and drawings through Contact Us. The quotation should state whether it covers the motor only, a prototype configuration or any additional hydraulic components.