1. Short-time working system (single braking) t: For the short-time working system of the
braking resistor box, it refers to the time required for the resistance to not reach the maximum temperature rise of 63.3% after the rated power is applied. TB≤τ=200s
2. Long-time working system (single braking) t: When the rated power is applied, the maximum temperature rise exceeding the resistance is 63.3% tB>τ=200s
3. Intermittent work system (repetitive braking) ED%: the percentage of the resistor's energizing time in a cycle, and the energizing time does not exceed the thermal equilibrium time constant τ.