High Country Tek HFS-2Q - Manual (Page 14)

Hydraulic Fan System Controller : HFS - 2
Fan Reverse Output :
This feature is designed to ‘de-clog’ the fan protection guard and cooling elements and not
as a permanent running option.
The output drive to the coil is rated to 3.3Amps maximum ( at controller supply voltage )
and is either ON or OFF with no proportionality or ramp functions associated.
The ‘Purge’ sequence will cancel if at any time, an overtemp alarm is detected. The two
individual ‘Purge’ methods and the possible adjustments are noted below.
The ‘Reverse’ sequence is specific to avoid damage to the fan blades and the motor/hydraulic system and is a
follows ( see page 30 of this manual for more details ):-
1. Reverse command detected ( manual or Auto reverse signal ) .
2. Fan proportional control valve ramped DOWN to give zero fan speed at ramp rate set in software
Reverse Sequence :
3. Fan stopped ‘Dwell’ time starts if ( seconds ) value set in software.
4. Reverse valve O/P switched ON ( change hydraulic state )
5. Proportional valve ramped UP to reverse current limit set in software
6. Reverse command released ( manual or Auto reverse signal ).
7. Fan proportional control valve ramped DOWN to give zero fan speed at ramp rate set in software
8. Reverse valve O/P switched ( change hydraulic state to original )
For this feature to be activated, the operator must initiate the sequence by sending a momentary or pulsed
voltage signal ( vehicle supply level ) to the input marked ‘REVERSE I/P +’ on the controller. Upon receiving this
signal, the controller will follow the purge sequence to ensure correct and safe operation.
/ ( g y g )
9. Proportional valve ramped UP to required Forward speed.
Manual Reverse Initiation :
signal, the controller will follow the purge sequence to ensure correct and safe operation.
Re-initiation of the manual ‘Purge’ signal during a ‘Purge’ sequence will be ignored by the controller.
Fan Reverse Notes :
The software controls the purge feature such that if the momentary manual input is continuously activated ( I.e.
short circuited ), the sequence will complete once, ensure the fan is re-activated in the forward direction and wait
until the input is cleared and then re-initiated before another purge sequence is allowed
Auto Fan Reverse :
until the input is cleared and then re initiated before another purge sequence is allowed.
This automated feature can be used to ensure free air flow through the radiator on a regular basis without
operator intervention.
Adjustments are available in the set-up software for:-
• Auto Purge feature ON/OFF select
• Auto Repetition rate ( set in minutes up to a maximum of 180 )
• Time to run in reverse ( Purge time ) direction set in seconds ( 60 max ).
• Speed of fan in reverse ( as a % of fan maximum forward speed )
The manual ‘Purge’ feature can be actioned between automated operations as required. 14