If you've ever burned out an actuator or had it overheat mid-operation, duty cycle was probably the culprit. It's one of the most overlooked specifications — and one of the most critical. This guide breaks it down clearly so you can choose the right actuator and avoid costly failures.

What Is Duty Cycle in a Linear Actuator?

Duty cycle is the ratio of "on time" (when the actuator is actively moving) to the total cycle time (on time + rest time),
expressed as a percentage.

Simple example:

• Actuator runs for 10 seconds, then rests for 90 seconds
• Total cycle = 100 seconds
• Duty Cycle = 10/100 = 10%

Most standard electric linear actuators are rated at 10% or 20% duty cycle. This means the motor can only be energized
for 10–20% of the time before it needs to cool down. Running beyond this limit causes the motor to overheat, leading to
premature failure — or in severe cases, permanent damage.

Why Duty Cycle Matters for Your Application

Different applications demand very different duty cycles. Getting this wrong is one of the most common (and expensive)
mistakes in actuator selection.

Low-Duty-Cycle Applications (10–20%) — Ideal for Most Standard Actuators

These applications activate the actuator occasionally and allow adequate rest time between operations:

• Hospital bed adjustments — a patient repositions a bed angle a few times per hour
• Recliner chair mechanisms — intermittent position changes
• Solar panel trackers — slow, incremental adjustments throughout the day
• Agricultural equipment gates — opened/closed a limited number of times per day
• Industrial machine guards — open once per production cycle

A JDR Standard Actuator (e.g., FY011, FY014 Series) rated at 10% duty cycle is perfectly suited for these use cases.

High-Duty-Cycle Applications (50–100%) — Requires Industrial-Grade Actuators

These applications demand near-continuous or rapid-cycling motion:

• Conveyor diverters — cycling every 5–10 seconds continuously
• Robotic assembly arms — repetitive pick-and-place cycles
• Automated sorting systems — hundreds of operations per hour
• Continuous ventilation dampers — constantly adjusting airflow

For these applications, you need an actuator specifically rated for higher duty cycles — typically using larger motors,
better thermal management, and heavier-duty gear trains.

Understanding Duty Cycle Ratings: A Practical Breakdown

Pro Tip: These ratings are typically based on room temperature (25°C). In hot environments (40°C+), the effective
safe duty cycle may be 20–30% lower. Factor in ambient temperature when specifying actuators for outdoor or highheat applications

How to Calculate Required Duty Cycle for Your Application

Follow these four steps:

Step 1: Define your operation cycle

• How long does the actuator need to extend/retract? (e.g., 8 seconds)
• How long is the rest period before the next cycle? (e.g., 52 seconds)

Step 2: Calculate duty cycle $$\text{Duty Cycle} = \frac{8}{8 + 52} \times 100% = 13.3%$$

Step 3: Add a safety margin Always select an actuator rated at least 50% higher than your calculated duty cycle. In this
example, target an actuator rated at 20% duty cycle minimum.

Step 4: Check thermal ratings If your environment exceeds 25°C, apply the derating factor from the actuator's datasheet.
For example, a 20% rated actuator in a 40°C environment may be safely operated at only 14%.

What Happens When You Exceed the Duty Cycle?

Exceeding duty cycle limits is a guaranteed path to actuator failure. Here's the progression:

1. Motor windings overheat → insulation degrades

2. Internal thermal protection trips (if equipped) → actuator stops unexpectedly mid-operation

3. Repeated overheating → winding insulation burns out → actuator fails permanently

4. Gear wear acceleration → reduced lifespan even if motor survives

Many actuators include thermal overload protection (a thermal switch inside the motor). This automatically cuts power
when the motor reaches its temperature limit. This is a safety feature, not a substitute for correct duty cycle selection.

Duty Cycle and IP Rating: An Important Combination

High-duty-cycle actuators in outdoor or wet environments face a double challenge: heat from operation AND
environmental stress. When specifying for these conditions:

• Select actuators with IP66 or IP67 ratings (protected against water jets and immersion)
• Ensure the duty cycle rating is tested at your expected ambient temperature
• Consider actuators with aluminum housings for better heat dissipation vs. plastic-body units

JDR's Industrial Actuator Series (FY015, FY021 series) are engineered for demanding duty cycles in harsh conditions, with
IP66 sealing, 12–72V DC operation, and force ratings up to 10,000N (2,248 lbs).

Comparing Actuators by Duty Cycle: JDR Product Recommendation Guide

Frequently Asked Questions About Duty Cycle

Q: Can I run a 10% duty cycle actuator continuously for short periods?

A: For very brief periods (a few minutes), most actuators with thermal protection will simply cut out rather than fail permanently. However, repeated overheating degrades motor life significantly. For any application approaching continuous use, specify a higher-rated actuator.

Q: Does speed affect duty cycle?

A: Indirectly, yes. Faster actuators complete their stroke in less time, so for the same application cycle, they technically have a lower duty cycle (shorter on-time). However, faster motors also generate more heat per second. Don't assume a faster actuator can be cycled more often.

Q: Is there a way to extend the effective duty cycle of my current actuator?

A: Yes — active cooling. Some industrial applications add small fans or cooling fins around the actuator housing to dissipate heat faster. However, this adds complexity and cost. If you're routinely hitting duty cycle limits, the proper solution is to upsize to a higher-rated actuator.

Q: How do I know if my actuator has thermal protection?

A: Check the datasheet or product specifications. JDR actuators include thermal overload protection in the motor, which is indicated in the technical specifications. Contact our engineering team if you need clarification.

Summary: Key Takeaways

• Duty cycle = on time ÷ total cycle time × 100%
• Most standard actuators are rated at 10% duty cycle — enough for most intermittent applications
• Always add a 50% safety margin to your calculated duty cycle requirement
• Temperature matters: hot environments reduce effective safe duty cycle
• For high-cycle industrial applications, specify industrial-grade actuators with higher thermal ratings
• IP66 sealing + high duty cycle is the right combination for outdoor industrial use

Need help selecting the right linear actuator for your duty cycle requirements? Use our Engineering Force Calculator to determine force requirements, or contact our engineering team for custom application support. Browse our full range of industrial linear actuators and medical actuators.