daleyd
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- Wrexham, North Wales
It’s as much to do with the type of load rather than the drive, most of my work has been with fans and pumps rather than machine tools so have been the variable torque loads. There’s usually a setting in the drive so you can optimise it for which type of load it will be connected to.not sure about constant torque throughoout the lower frequencies. Pretty sure it drops off, or is it the other way round? if I remember rightly there's a ratio between the frequency and the motor output torque, and you can calculate that loss fairly accurately. When I get an hour or two, will have to refresh my memory as it's a while since I've commissioned any. Did plenty of them on the last HVAC job, big AHU's and fan sets, those were all danfoss drives, but the theory was the same..
Most drives are capable of providing constant torque though, if the load requires it - usually up to the base frequency after which it will drop off.