MotorsQuestion 346 of 1506

A 20 hp open drip-proof motor has a service factor of 1.15. What load can it carry for short-term use?

  1. 17.4 hp
  2. 21.15 hp
  3. 23 hp
  4. 25 hp
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Correct answer: 23 hp

20 hp × 1.15 = 23 hp. It is not good practice to run continuously in the service factor range.

Source: Troubleshooting Motors and Controls (Dickson-Self), 6.1: Testing Motor Components

Practice motors

Questions last reviewed: 18 October 2026