What torque is specified for NR power-on transient?

What torque is specified for NR power-on transient?

• A. 108% (10 sec)
• B. 115% (6 sec)
• C. 80% (10 sec)
• D. 95%

Answer: (A)

During a power-on transient, a brief over-torque is allowed to help the system start, expressed as a percent of the rated torque with a time limit. The NR spec sets this over-torque at 108% for 10 seconds, giving enough starting torque to overcome inertia and friction while keeping heat and mechanical stress within safe limits. A larger overshoot like 115% for only 6 seconds would be more aggressive and may exceed safe transient limits; 80% would not provide enough torque to start reliably; and 95% without a defined duration is ambiguous and not aligned with NR’s specified transient window.

During a power-on transient, a brief over-torque is allowed to help the system start, expressed as a percent of the rated torque with a time limit. The NR spec sets this over-torque at 108% for 10 seconds, giving enough starting torque to overcome inertia and friction while keeping heat and mechanical stress within safe limits. A larger overshoot like 115% for only 6 seconds would be more aggressive and may exceed safe transient limits; 80% would not provide enough torque to start reliably; and 95% without a defined duration is ambiguous and not aligned with NR’s specified transient window.