Duty Cycles: Continuous vs. Intermittent (S1, S3, S4...)
K
KeybokWiki guide
kWiki · Services
Here's a complete overview of "Duty Cycles: Continuous vs. Intermittent (S1, S3, S4...)" for you.
kWikiservices
Duty Cycles: Continuous vs. Intermittent (S1, S3, S4...)
Why a motor rated for 10kW continuously (S1) can deliver 15kW for short bursts (S3). And why a crane hoist needs a different motor than a water pump.
DATE: 2026-05-17
Two motors, both labeled "10kW." One costs half and is half the size. The catch? The duty cycle — how long the motor can deliver that 10kW before overheating.
The Core Concept: Thermal Capacity
When a motor runs, it generates heat. The motor absorbs some heat before reaching the insulation limit.
If it reaches thermal equilibrium: S1 (continuous) rating.
If it runs briefly and stops: it never fully heats up. It can deliver MORE power during that brief run.
