Great Plains NTA3007HD Operator Manual - Manual (Page 93)

Adjustments 89
04/04/2011 166-207M
Bypass with LS or PFC Closed Syste ms
Refer to Figure 95
Turn the adjustment knob counter-clockwise to increase
flow.
Turn the adjustment knob clockwise to decrease flow.
Turning it fully clockwise stops all bypass flow.
Failure to use the bypass valve on load-sensing tractors
may cause major tractor damage.
7. Adjust down-pressure before adjusting bypass.
8. With tractor at half throttle, adjust tractor flow-control
valve so that openers raise and lower at a reason-
able speed. Keep tractor at one-half throttle for the
remaining step.
Note: The faster openers raise and lower, the greater po-
tential for oil heating, premature wear or tractor
damage. The higher the bypass pressure, the
greater the potential for oil heating and premature
tractor damage. At the same time, for proper open-
er operation the bypass valve must be set at least
20 bar (300 psi) above the opener down-pressure
setting when the tractor is at one-half throttle.
Therefore, you should set the bypass valve as low
as possible while staying at least 20 bar (300 psi)
above the opener down pressure setting.
9. Slowly open the bypass valve until the down-pres-
sure gauges just start to decline.
10. Turn the bypass knob one turn in the closing direc-
tion.
11. Lock the knob at that setting.
While 140 bar (2100 psi) is a good starting point for set-
ting the bypass valve, if you consistently operate the drill
with low opener down pressure you can set the bypass
valve below 140 bar (2100 psi). If you consistently oper-
ate the drill with very high opener down pressure, you
may need a bypass-valve setting above 140 bar
(2100 psi).
Null4:
Figure 95
Bypass Adjustment
29422
W
C
T
B
k
r
w
c
t
B