Definition
An electrical rating that specifies the maximum load a component, such as a relay, solenoid, motor, or generator, can carry indefinitely without overheating or being damaged. A device with a continuous-duty rating is designed and built to operate under that load for an unlimited period of time.
Plain English
It tells you how much electrical load a part can handle without stopping. The part is built to run at that level all day without getting too hot or wearing out.
Context Anchor
Seen in aircraft electrical, starter, motor, relay, and equipment specifications when deciding whether a component may be left energized or running.
Derivation
‘Continuous’ comes from Latin continuus, meaning ‘uninterrupted.’ ‘Duty’ in electrical engineering refers to the working load placed on a device. So a continuous-duty rating is simply the load level the part can carry without interruption.
Why Pilots Care
Ensures critical electrical devices remain reliable during extended engine cranking, long flights, or continuous system demands without risk of thermal failure.
Analogy
A desk fan is usually meant to run for a long time, but a handheld kitchen mixer may need short breaks. The difference is the kind of duty each device is designed for.
Intuition Check
Do not read continuous-duty as meaning unlimited in every situation. It means continuous only at the specified load and under the conditions the part was rated for.
Example Sentence 1
The master solenoid is a continuous-duty component because it must remain energized for the entire flight.
Example Sentence 2
Choose a contactor with the correct continuous-duty rating when installing a new avionics power relay.