DOC-0017-03-EN: AC15 Series - Hardware Installation Manual
DOC-0017-03-EN-B 04.04.2023 43 (125)
Dynamic Brake Resistor Protection Current Calculation:
=
× 1.1
Where:
= Resistor Protective Current (A)
= Continuous Braking Power (W)
= Dynamic Braking Resistor (Ω)
Dynamic Brake Resistor Peak Current Calculation:
=
Where:
= Dynamic Brake Resistor Peak Current (A)
= Dynamic Brake Resistor Threshold Voltage (V): 382V (230V products) / 764V (400V products)
= Dynamic Braking Resistor (Ω)
Dynamic Brake Resistor Peak Instantaneous Power Calculation:
=
²
Where:
= Dynamic Brake Resistor Peak Instantaneous Power (kW)
= Dynamic Brake Resistor Threshold Voltage (V): 382V (230V products) / 764V (400V products)
= Dynamic Braking Resistor (Ω)
7.5 AC Motor Chokes
The maximum rate of Voltage rise (dv/dt) present at the inverter output can be as high as 10,000V/µs.
Adding an AC Motor Choke between the inverter output and motor:
1. Reduces the dv/dt and peak voltages present at the motor, which in turn reduces the stress applied
to the motor insulation.
2. Eliminates potential nuisance overcurrent trips in installations with long motor cable runs.
3. Limits parasitic capacitance flowing to earth.
Refer to ‘Chapter 11: Compliance’ for maximum motor cable lengths.
Where a choke is deemed necessary, Parker suggest the following AC Motor Choke ratings:
1ø, 230V Products
Frame
Motor
Power
Inductance
Rated Current
Peak Output
1