Power Supply for Winches and Linear Actuators
A power supply for a winch or linear actuator must match the motion cycle, not just the motor’s nominal voltage. An OEM purchase decision needs four separate checks: continuous demand, acceleration and stall demand, energy returned during stopping or lowering, and the required behavior after a fault. A supply that passes an unloaded demonstration may still reset the controller at the worst point of the machine cycle.
The WEHO SP-500-48 provides a concrete example of the boundary. Its photographed nameplate specifies 48 V and 10 A, or 480 W by multiplication. Those values do not establish a permissible motor-start pulse, a regenerative energy sink or approval for lifting equipment. Treat it as a candidate for an engineering review, not a prequalified winch supply.
Send a motion profile with the RFQ
Ask the machine designer for the electrical demand at the controller’s DC input. Motor phase current, battery current and the AC input current printed on a supply are different quantities. Record actual loaded movement, including the shortest repeat cycle, rather than quoting only the actuator’s average running current.
| Operating event | Information the buyer should obtain | Acceptance decision |
|---|---|---|
| Steady travel | DC input voltage range, current and duration at rated mechanical load | Continuous capability must remain valid in the final cabinet. |
| Start or reversal | Peak current, pulse duration, repetition and controller current limit | Require a documented transient capability or a sample test covering the event. |
| Blocked actuator | Stall detection, timeout, brake action and restart logic | The machine must reach its intended safe condition without relying on an unspecified supply response. |
| Stopping or lowering | Returned energy, maximum bus voltage and energy-management method | Confirm the complete drive architecture can contain the event. |
Keep the motor/controller revision, gearing, load and control settings in the test record. A change in any of them can invalidate an earlier supply selection even when the supplier part number is unchanged.
Interpret the exact SP-500-48 rating
The original sheet lists 48 V, a 0–10 A output range and an enclosure of 185 × 120 × 93 mm. Its overload row describes output interruption and automatic recovery within a 105–135% band. That protection threshold is not an additional continuous operating range or a guaranteed start-boost curve. Repeated protection cycling is not an acceptable substitute for a validated motion profile.
Der SP-500 product page also lists the 48 V version at 10 A and 480 W. However, its input table describes switched AC ranges, while the retained sheet lists 85–264 VAC and the photographed label says 100–240 VAC. Ask the supplier to reconcile the input architecture for the delivered revision; do not choose a switch setting from a generic web table.
Plan for energy flowing back from the load
A moving load can drive the motor as a generator during deceleration or downward travel. Energy returning through a controller can raise the DC bus voltage when the system cannot absorb it. The referenced engineering guidance on energy recovery explains this mechanism and the resulting overvoltage behavior. It supports asking the question; it does not qualify this WEHO model or a particular braking device.
Request a written energy-management proposal from the drive integrator: allowable returned energy, peak bus voltage, braking component ratings and behavior if the mains disappears. A braking resistor, energy buffer or regenerative supply is a system-design choice, not an interchangeable accessory. Do not assume a standard AC/DC supply will absorb current merely because it can deliver the same current.
Qualify the assembled cabinet, not a loose supply
The SP enclosure has two guarded terminal rows and original threaded chassis fixing provisions. Preserve access to the actual terminal positions and the documented airflow path. Terminal groups, remote-control and sense connections must follow the matching revision’s drawing; spare-looking screws are not spare motor outputs. The assembly illustrations show mechanical interface planning with the supply terminals empty, not an energized or qualified drive circuit.
Agree a sample test matrix before the purchase order: minimum and maximum intended AC input, the hottest intended cabinet condition, repeated loaded starts, the specified stall response and the highest-energy stop. Record DC voltage at the drive, protection events and recovery behavior. Qualified personnel should control mechanical hazards and energized measurements. A power supply is not a load-holding brake, emergency-stop system or lifting-safety approval.
Make supplier approval reproducible
For a sample request, send the controller data sheet, the measured or specified motion profile, cabinet drawing, required destination documentation and the expected order quantities. Ask the supplier to identify which operating events are covered by its data and which require testing. A clear written limitation is more useful than an unsupported assurance that a “500 W” product will work.
After a successful qualification, retain the accepted sample identification, exact nameplate, mechanical drawing, firmware/control settings and test limits. Require notification of relevant revisions before substitutions or repeat orders. Evaluate a replacement against the same motion and recovery matrix; matching 48 V alone is insufficient.
Questions buyers should resolve
Can a 10 A supply start a motor that briefly needs more than 10 A?
Only if the exact supply’s documented transient response and the complete load profile support it. An overload-protection percentage alone does not establish that capability.
Does adding a battery automatically solve the problem?
No. Battery charging, isolation, fault current and returned energy require a designed interface. Do not connect a battery directly to an undocumented supply output.
To discuss an OEM supply candidate, send WEHO the motion profile and cabinet requirements. Request a revision-specific response and sample evaluation before agreeing quantity, availability or delivery commitments.
