High Country Tek HFS-2Q - Manual (Page 13)

Hydraulic Fan System Controller : HFS - 2
Fan ‘MAX speed’ setting :
This is called ‘ Max Vlv Current %’ in the software and allows current to be adjusted from 0 – 100 % PWM output.
If Max Valve Current is set to zero (0) all other settings will also go to zero.
Fan ‘MIN speed ‘setting :
This is called ‘ Min Vlv Current %’ in the software and allows current to be adjusted from 0 – 100 % PWM output
set by ‘Max Vlv Current’ above.
Ramp Settings :
The user programmable ramp Up and Down times are applied to limit the controllers rate of change in output
current to a value that prevents damaging the hydraulic system components and the fan blades.
The ramp rate is set in seconds (s) for a full scale current output change in the range of 1 to 10 seconds.
This ramp time should be set low enough not to interfere with the temperature control loop response but high
enough to give smooth system operation.
The set-up software allows the dither frequency ( PWM frequency ) to be set from ~30Hz to ~250Hz to cater for the
known range of proportional valves that could be used for this application.
Dither Frequency Settings :
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