High Country Tek HFS-2Q - Manual (Page 30)

Hydraulic Fan System Controller : HFS - 2
Fan ‘Reverse’ profile ( reverse acting control valve ):
Fan speed Profile.
Controller Output
profile to inverting type
pressure control valve.
9
11
6
1
12
7
2
4
8
3
10
14
13
5
Reverse output to
directional valve.
Normal ‘Forward’ running fan
speed determined by controller.
1
Fan at maximum speed for
Reverse time period set in
8
speed determined by controller.
Manual or automatic ‘Purge’ or
reverse fan trigger detected here.
2
Fan speed decays to zero at
‘Ramp Down’ rate set in
software.
3
‘Purge’ timing cycle expired, ramp
fan to zero at ‘Ramp Down’ rate
set in software.
9
Reverse time period set in
software. This speed may be less
than forward to protect fan.
‘Dwell’ timer started to allow fan
10 software.
‘Dwell’ timer started to allow fan
inertia to fully dissipate and fan
stop.
4
Reverse output turned ON to
energize directional valve.
5
Dwell timer started to allow fan
inertia to fully dissipate and fan
stop.
Reverse output turned OFF to
de-energize directional valve.
11
Output signal to proportional
12
g
Fan rotation increased to
7
Output signal to proportional
valve started fixed mS after
reverse valve signal to prevent
hydraulic ‘lock’
6
valve started fixed mS after
reverse valve signal to prevent
hydraulic ‘lock’
Fan rotation increased to
‘Forward’ running speed
determined by user setting at
‘Ramp Up’ rate set in software.
13
30
‘Reverse’ running speed
determined by user setting at
‘Ramp Up’ rate set in software.
Ramp Up rate set in software.
Normal ‘Forward’ running fan
speed determined by controller.
14