10
Project planning
Selecting the braking resistor
Operating Instructions – MOVIMOT
®
flexible
365
10.8.4
Calculation example
Given
•
Peak braking power: 1 kW
•
Average braking power: 0.4 kW
•
Braking time: 7 s
•
Cycle duration: 28 s
Required
•
Braking resistor BW...
Calculation
1.
Determining the cyclic duration factor
•
Cyclic duration factor cdf = braking time/cycle duration
•
Cyclic duration factor cdf = (7 s/28 s) × 100% = 25%
When selecting the braking resistor, observe the assignment of inverter and bra-
king resistor, see chapter "Technical data and dimension sheers" > "Braking resist-
ors".
2.
Determine the overload capacity
Determining the overload factor, e.g. for a flatpack resistor at a cyclic duration
factor cdf of 25% from the respective diagram.
•
Overload factor OF = 3.0
3.
Calculating the braking power at 100% cdf
•
Braking power 100% cdf = average braking power/overload factor
•
Braking power 100% ED = 0.4 W/3.0 = 0.133 kW
•
The braking power of the braking resistor at 100% cdf must be ≥ 0,133 kW.
4.
Selecting the braking resistor
•
For MOVIMOT
®
flexible, the minimum permitted braking resistance value =
100 Ω, see chapter "Technical data and dimension sheets".
•
Selected braking resistor: BW100-005/K1.5
•
Resistance value R
BW
= 100 Ω
•
Peak braking power: 1.8 kW
•
Current-carrying capacity at 100% cdf: 0.2 kW
29128668/EN – 12/2019