Mining and mineral-processing sites use motor-driven equipment for conveying, crushing, screening, pumping and ventilation. These applications can have very different starting, speed-control and environmental requirements.
This guide explains starting torque, duty, acceleration and stopping, then connects those principles to the motor and site information needed for equipment selection.
Power, Torque and Starting Duty
Motor power describes a rate of mechanical work, while torque describes turning effort. A drive selection must account for the turning effort the load needs across its operation, including starting. A conveyor that starts under load can make different demands from one that starts empty.
Overload capacity is also a time-based requirement. A brief starting demand and a continuously demanding load are different duties. The equipment’s applicable current ratings and duty definitions must be checked against the actual application.
Acceleration and Stopping Affect the Whole Machine
Acceleration involves both overcoming the load and changing the speed of moving equipment. Stopping also needs consideration: allowing a load to slow naturally is different from requiring a controlled stop within a defined time.
Some applications need a specific braking arrangement, particularly where the load’s motion influences the motor. The mechanical system, drive and any braking equipment must be assessed together. A selected deceleration setting alone does not establish that the machine can stop as required.
Example: An Empty Start Versus a Loaded Start
Two conveyors with the same motor power can have different starting requirements if one starts empty and the other starts carrying material. State the actual starting condition, required acceleration and duty cycle. This information helps assess drive capacity and overload requirements against the motor and machine specification.
Identify the Equipment and the Task
Start with what the motor operates and what you need to achieve. Is this an exact replacement, a new installation, a speed-control upgrade or a fault enquiry?
A conveyor starting under load needs a different assessment from a ventilation fan or a dewatering pump. Include the machine manufacturer and model, existing controller details and any available drawings or project specification.
Confirm Supply and Motor Ratings Separately
Do not assume that every mine uses the same voltage. Provide the incoming electrical supply details and a clear photograph of the motor nameplate.
- Incoming supply voltage, phase and frequency.
- Motor rated voltage, current, power and speed.
- Motor type and existing connection details, where documented.
- Existing drive or starter model, including complete suffixes.
A motor’s kW rating is only part of the selection. The proposed equipment must be checked against motor current, load duty and the applicable manufacturer ratings.
Conveyors, Crushers and Feeders
Explain whether the equipment starts empty or loaded, how frequently it starts and whether the load changes during operation. Include any required speed range and existing starting method.
For conveyors, mention multiple motors, inclined travel, mechanical brakes and any specified load-sharing requirements. These details affect the control arrangement and should be reviewed with the responsible engineering team.
For crushers, screens and feeders, share the machine manufacturer’s operating requirements. Do not assume that a standard drive selection based only on motor power covers starting peaks, repeated starts or the machine’s mechanical limits.
Pumps and Ventilation Fans
For a pump enquiry, identify whether the duty involves clean water, slurry, wastewater or dewatering. Send the pump and motor details and explain whether the task is transfer, pressure control, drainage or another process.
For ventilation fans, provide the fan and motor information, current controls and required operating range. Safety-critical ventilation requirements need specialist review.
Adding a drive does not by itself confirm pump sizing, process performance or energy savings. The motor, driven equipment and operating conditions must be assessed together.
VSD or Soft Starter?
A VSD controls motor speed during operation. A soft starter primarily manages starting and stopping, rather than providing continuous variable-speed operation.
Establish whether you need speed adjustment or a different starting method before requesting a product. Loaded starting, acceleration time, starts per hour and required stopping behaviour are relevant to the assessment.
Neither product category automatically resolves every application requirement. Refer the exact motor and load information for selection.
Dust, Water and Installation Location
State whether the equipment will be underground, outdoors, inside a control room or mounted in a panel. Describe dust, water exposure, temperature, vibration and any relevant site conditions.
Do not assume that an ordinary drive, enclosure or control component meets mine requirements. Enclosure selection, cooling and any required rating adjustments need review against the exact product documentation and installation conditions.
If the project has a hazardous-area specification, provide the classification and mandatory equipment approvals. An IP rating does not establish explosion protection.
Control Interfaces and Safety Requirements
Include the existing PLC or control-system details, required signals, communications and any fitted option modules. Similar terminals or matching network connectors do not establish compatibility.
Conveyor emergency stops, interlocks, braking and other safety-related functions require qualified assessment. A drive’s available safety feature does not by itself establish that the complete machine or installation meets its requirements.
A Practical Planning Checklist
- Equipment or process description and the reason for the enquiry.
- Motor nameplate photograph and incoming supply details.
- Complete existing drive, starter and relevant controller model numbers.
- Loaded or unloaded starting, duty cycle and required speed range.
- Control signals, communications and required accessories.
- Installation location, environment and mandatory project approvals.
- Drawings, specifications or a bill of materials where available.
- Quantity, destination and required date.
For an urgent breakdown, include the failed model, symptoms and fault code. Accurate identification helps the team assess an exact spare or a potential alternative.
Technical Note: This guide provides general enquiry information. Final equipment selection, mine approvals and safety or compliance decisions require qualified assessment. Installation, programming and commissioning are included only where expressly quoted.
Relevant Catalogue Examples
View the Delta C2000 drive listing, or email info@softcoregroup.co.za with your application details.
Technical Resources
Visit our Technical Resources & Manuals page for documentation and guidance on requesting information for the exact model.