Brake resistor value for ACS880
1. how to calculate the brake resistor value for a ACS880 drive according to supply voltage and motor rating?
2. the abnormal value of parameter 43.10 (brake resistance) can damage drive after turn on 3phase input power supply?
thanks in advance
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the choice of a braking resistor depends on the type of load and therefore on the inertia that it can have, a drive with a large flywheel and a conveyor, even if they have the same motor, will have a different braking resistor, precisely because the conditions of inertia reported to the motor axis are different.
Furthermore, the time parameter must be considered, that is, how long the load must be stopped or slowed down.
From these indications, through some kinematics calculations, the value of the kW of resistance necessary for each application is obtained.
This in principle, but it must be taken into account that the braking chopper of a drive cannot have power beyond the nominal one, therefore a resistance is chosen according to the minimum impedance that the drive accepts as a "load" in ohms and power. suitable for the load of the connected motor.
In some cases, there are no suitable resistances in the catalog and therefore it is necessary to resort to "construction", there are companies specialized in this type of activity. As for the parameter you indicated, I suggest not to "force" the minimum values that are listed in the HW manual of each drive with arbitrary values.
Hope this help you
2.Ohm's Law can be used to estimate values for the DC link components.
Power = Voltage (dc link) *Current = Current 2 * Resistance = Voltage 2 / Resistance
2.However you can find basic DBR selection table as per drive rating in Hardware Manual.
3. Your drive is having over voltage protection additional to this if any dc over voltage seen then drive will trip. If it is frequent then it can damage your drive.