What is the motor percentage size of protection needed above the FLA?

The motor percentage size of protection needed above the Full Load Amperage (FLA) is typically set at 125%. This requirement ensures that the overload protection device is capable of handling certain transient conditions and surge currents that motors may experience during startup or operation without tripping unnecessarily.

When motors start, they draw a significant amount of current, often much higher than their rated FLA, especially for a short duration. Setting the protection level at 125% of FLA allows for some leeway to accommodate these brief inrush currents while still protecting the motor from overheating due to sustained overload conditions. It is important to ensure that the protection system is not overly sensitive, as this might cause frequent undesired shutdowns during normal startup or operational spikes. Therefore, the 125% value is recognized as a standard that balances safety and operational reliability for many motor applications.