How an electric winch motor is started

An electric winch is driven by an electric motor, and how that motor is started is more than a detail: it affects the surge of current drawn at the moment of starting, the demand placed on the electrical supply, and whether the winch starts with a jolt or smoothly. There are several ways to start a winch motor, from the simplest direct switch-on to a full inverter drive, each with its place. Choosing the right one depends on the motor, the supply and the job, and here is how they differ, building on how an electric winch works and the line pull it delivers.

Direct on line starting

The simplest way to start a winch motor is direct on line, switching the full supply voltage straight to the motor in one step. It is simple and cheap, and for small winches it is perfectly fine, because a small motor's starting surge is modest. But on a larger motor, switching full voltage straight on draws a heavy surge of current and starts the winch with a jolt, which can stress the supply and the winch. So direct on line suits small winches where the starting surge is small, but for larger motors a gentler method is usually better. So it is the default for small winches and the starting point against which the gentler methods are judged.

The starting surge

When a motor starts, it draws a surge of current far above its running current, called the inrush, and the bigger the motor and the harder the start, the bigger that surge. This inrush stresses the electrical supply and can trip protection or dim other equipment, and it starts the winch abruptly. So much of the choice of starting method is about taming this surge, reducing the inrush so the supply is not stressed and the winch starts more gently. Understanding the starting surge explains why the gentler methods exist, because a large motor started direct on line can draw a surge the supply cannot comfortably give, which the other methods are designed to reduce.

Star-delta starting

Star-delta starting reduces the starting surge by first connecting the motor windings in a star arrangement, which applies a lower voltage and draws less current, then switching to delta for full voltage once the motor is running. This cuts the inrush and softens the start compared with direct on line, which suits mid-size motors where a direct start would draw too heavy a surge. It is a long-established, economical way to reduce starting current. So star-delta is a common choice for medium winch motors, giving a gentler start and a smaller surge than direct on line, at modest cost, though it still steps rather than ramps the voltage, so the start is softer but not perfectly smooth.

Soft starters

A soft starter reduces the starting surge by ramping the voltage up smoothly from low to full over a short time, so the motor accelerates gently rather than being switched straight on or stepped. This gives a smooth, gentle start and a reduced inrush, easier on the winch, the load and the supply than direct on line or star-delta. So a soft starter suits winches where a smooth, gentle start matters, protecting the mechanism and the load from the jolt of an abrupt start and easing the demand on the supply. So a soft starter is a good choice where starting smoothly is valued, giving a gentler ramp than star-delta's step, though it controls only the start, not the running speed.

Protecting the motor and supply

However the winch is started, the motor and supply need protection, against overload, against a stalled motor, and against electrical faults, so the starting gear usually includes the protection that guards the motor and the circuit. A gentler starting method also helps protect the supply by reducing the surge it must give, but proper overload and fault protection is needed whatever the method. A winch motor run without protection can be damaged by an overload or a fault that protection would have caught. So protecting the motor and supply goes hand in hand with the starting method, because starting the winch is only part of it; the motor must also be guarded through its working life, and the starting gear is where that protection usually sits.

Stopping and reversing

Starting is only half the story, because a winch also has to stop and, on most jobs, reverse to lower as well as lift, so the control gear handles stopping and changing direction as well as starting. How smoothly the winch stops and reverses matters as much as how it starts, and the more capable methods, especially an inverter, control stopping and reversing smoothly too, not just starting. A winch that starts gently but stops or reverses with a jolt is only half sorted. So stopping and reversing are part of the control picture along with starting, because the winch works in both directions and must be controlled cleanly throughout, which the right control gear provides across the whole of its operation.

Inverter drives and speed control

An inverter drive, or variable frequency drive, goes furthest: it controls the motor's speed throughout, not just at starting, by varying the frequency of the supply to the motor. This gives a soft start and full control of speed, so the winch can run slow or fast as needed and start and stop smoothly. So an inverter suits winches where variable speed and fine control are wanted, as well as a gentle start, giving the most control of any method. The cost is more than the simpler starters, but in return the winch gains full speed control. So an inverter drive is the choice where speed control and the smoothest operation are worth it, doing far more than just easing the start.

Matching the method to the winch

Putting it together, the starting method is chosen for the motor size, the supply and the job: direct on line for small winches, star-delta or a soft starter to tame the surge on larger motors, and an inverter where speed control and the smoothest operation are wanted. No one method is best for everything; the right choice depends on how big the motor is, what the supply can give, and whether gentle starting and speed control matter. So we look at the winch, the supply and the way it is used together to advise a starting method that suits, taking in how the electric winch works and the line speed the job needs.

Choosing the starting method with us

We advise on the right starting method for an electric winch, so it starts gently, suits your supply and gives the control you need. See the range in our winch catalogue, and read how an electric winch works and the line speed it gives. Tell us the motor size, your electrical supply and whether you need a smooth start or speed control, and we will advise on direct on line, star-delta, a soft starter or an inverter to suit, rather than leaving the winch to start harshly or overload the supply.

Frequently asked questions

Why does the starting method matter on a winch?

Because it affects the surge of current drawn at start, the demand on the supply, and whether the winch starts with a jolt or smoothly. A large motor started direct on line draws a heavy inrush that stresses the supply and starts abruptly, so the method is chosen to tame that surge and start the winch as the job needs.

What is star-delta starting?

A method that reduces the starting surge by first connecting the motor windings in star, applying a lower voltage and drawing less current, then switching to delta for full voltage once running. It suits mid-size motors, giving a gentler start than direct on line at modest cost, though it steps rather than ramps the voltage.

What does a soft starter do?

It ramps the voltage up smoothly from low to full over a short time, so the motor accelerates gently rather than being switched straight on or stepped. This gives a smooth start and reduced inrush, easier on the winch, load and supply, so it suits winches where starting smoothly matters, though it controls only the start, not the running speed.

When is an inverter drive worth it?

When variable speed and fine control are wanted as well as a gentle start, because an inverter controls the motor's speed throughout, not just at starting, so the winch can run slow or fast and start and stop smoothly. It costs more than the simpler starters, but in return gives full speed control and the smoothest operation.