Why is the simple brake test generally used for small motors only?

Concept:

The brake test is a direct method used to determine the output power of a motor by applying a braking force and measuring torque. It is typically used only for small motors because the heat generated during the test is manageable. In large motors, excessive heat is produced during braking, which is difficult to dissipate and may damage the motor or distort results.

Limitation of Brake Test:

For large motors, alternative testing methods like Prony brake or dynamometer-based methods are preferred due to better heat handling and accuracy.

Evaluation of Options:

Option 1: The simple brake test does not work with large motors –  Incorrect
It can technically work, but it's impractical due to heat issues.

Option 2: Large motors have lower efficiency –  Incorrect
Efficiency is not the limiting factor for brake test usage.

Option 3: Large motors produce excessive heat that is difficult to dissipate –  Correct
This is the main reason brake tests are limited to small motors.

Option 4: Small motors do not require cooling –  Incorrect
Even small motors need cooling, but the heat generated during testing is manageable.