Electric Hoist Specs: Power and Duty Cycle Guide

Defining the Electrical Load

The first step in specifying an electric hoist is calculating the actual electrical demand. Many buyers request a hoist based only on the maximum load weight. This approach is flawed. The motor must generate enough torque to lift that load at a defined speed while accounting for the efficiency of the gearbox and the friction in the chain or cable.

Start with the load. If you are moving 2,000 kg of raw material, the hoist must handle that weight plus a safety factor. Typically, manufacturers apply a factor of 1.5 to 2.0 to the rated load to ensure the motor does not overheat. This adjusted load determines the required torque. Torque, in turn, dictates the motor power. A heavier load at a higher speed requires significantly more wattage than a light load lifted slowly. If you specify a 10 kW hoist for a task that only needs 4 kW, you will pay for a larger machine, a heavier installation, and a larger electrical panel.

Matching Power and Speed

Power is not a single number. It is the product of torque and speed. Two hoists can lift the same weight, but one may take ten minutes while the other takes two. That difference is speed.

When writing your requirements, define the lift speed. For a production line, a consistent cycle time is often more critical than raw lifting power. A hoist that lifts too slowly can bottleneck the entire process. Conversely, a hoist that is too fast may be dangerous if the operator cannot control the descent of a heavy load.

Standard industrial hoists usually operate between 0.1 and 0.5 meters per minute. High-speed applications might require higher rates. Always ask the manufacturer for the speed at the rated load. Some specs list speed at no load, which is misleading. The speed under load is what matters for your production schedule.

Understanding Duty Cycle

Duty cycle is the most misunderstood specification in hoist selection. It describes how long the hoist can operate before it must rest to prevent thermal damage. It is expressed as a ratio of run time to total time.

A hoist with a 25% duty cycle can run for 15 minutes and must rest for 45 minutes. A hoist with a 100% duty cycle can run continuously. For a production line that operates in a continuous flow, a low duty cycle hoist will overheat and shut down. The controller will trip the motor, causing a line stoppage. This downtime is far more expensive than the initial cost of a higher duty cycle machine.

Match the duty cycle to your process. If your hoist lifts a part every 30 seconds, you need a high duty cycle. If you use the hoist to lift a tool once a day for maintenance, a low duty cycle machine is sufficient and much cheaper. Misjudging this requirement is the most common cause of hoist failures in industrial settings.

Hoist Voltage and Plant Compatibility

The voltage of the motor must match your plant’s electrical supply. Most industrial facilities use three-phase power, but the voltage varies by region. Common standards include 230V, 400V, and 480V.

Before ordering, verify the voltage at the point of installation. A hoist designed for 400V will not run on a 200V supply. You cannot simply plug a mismatched motor into the line. If your plant has a mix of equipment, check the distribution panel. Sometimes a specific circuit is reserved for high-power equipment like hoists.

If your existing voltage does not match the hoist requirement, you have two options. You can source a hoist with a motor that matches your plant voltage, or you can install a transformer to step the voltage up or down. Transformers are bulky, expensive, and draw their own power. It is almost always cheaper to buy the correct motor. Specify the exact voltage and phase number in your RFQ to avoid this issue.

Writing a Clear RFQ

A vague request leads to three problems. First, you receive quotes for different machines. Second, you waste time asking clarifying questions. Third, you may end up with a hoist that does not fit your space.

To get an accurate quote, provide the following data in your request for quotation:

1. Maximum load weight in kilograms.
2. Lift height, measured from the floor to the highest point of the load.
3. Required lift speed in meters per minute.
4. Duty cycle requirement, based on your cycle time.
5. Supply voltage and phase.
6. Mounting method, such as overhead rail or fixed post.
7. Required certification or safety standards.

Include a sketch of the installation area if possible. This helps the supplier advise on the correct hoist size and mounting hardware. It also prevents the purchase of a hoist that is too long or too short for the space.

Comparing Quotes Fairly

When you receive multiple quotes, do not pick the lowest price. Compare the specifications against your requirements first. A cheaper quote may use a lower duty cycle motor or a less efficient gearbox.

Look at the total cost of ownership. A hoist with a longer service interval and better build quality may cost more upfront but will have lower maintenance costs over five years. Check the warranty terms. A standard warranty might cover one year of parts and labor. Extended warranties can cover up to three years.

Also check the lead time. In a tight production schedule, a hoist that arrives in eight weeks is more valuable than one that is cheaper but takes four months to deliver. Factor shipping and installation costs into your comparison. Some suppliers include installation, while others sell the unit only. Ensure you are comparing like-for-like services.

Cost Drivers and Delivery Time

Several factors drive the price of an electric hoist. The most significant is the duty cycle. A high-duty hoist uses a larger motor and a more robust cooling system than a low-duty unit. This increases the cost by a substantial margin.

The second major driver is the lift height. A hoist that travels 20 meters is heavier and requires a stronger structure than one that travels 5 meters. The length of the chain or cable also adds cost.

The third factor is the voltage. Custom voltage motors can cost more than standard models because they require specific windings. If you need 480V in a region where 400V is standard, expect a premium.

Lead times vary by specification. Standard configurations are often in stock or can be produced quickly. Custom specifications, such as unusual voltages or extreme duty cycles, may require longer production runs. Always ask for a confirmed delivery date in writing. Do not rely on a verbal estimate.

Cost Driver	Impact on Price	Impact on Lead Time
Duty Cycle	High duty cycles increase motor size and cost significantly.	High duty cycle units may have longer production times.
Lift Height	Longer travel distances require heavier structures and more cable.	Standard lengths are often faster to source than custom lengths.
Voltage	Non-standard voltages may require custom motor windings.	Custom voltage motors often have longer lead times.
Load Capacity	Higher rated loads require stronger chains and gears.	High-capacity hoists may be made to order.
Mounting Hardware	Custom brackets or special attachments add to the cost.	Specialized hardware may need to be manufactured.

Final Checks Before Purchase

Before you sign the purchase order, run the numbers one last time. Confirm that the motor power matches your calculated load and speed. Verify the duty cycle against your actual production rhythm. Check the voltage against your plant’s electrical plan.

If you are unsure about any of these figures, consult your electrical engineer or a certified material handling professional. A small mistake in the specification can lead to a major failure on the production line. The goal is to buy the right hoist, not the most expensive one.