Determining Total Flow Demand

1. Check flow setting for each function independently. (See implement operator's manual, applications section, to determine correct motor flow settings.)

Examples of functions which may cause the pump to operate at high pressure:

  • Down pressure systems (drills, air seeders, disks)-usually can be considered to be zero flow demand after completion of raise or lower cycle.
  • Auxiliary flow control valves (vacuum flow control)-Completely open implement flow control valve and adjust tractor flow rate to desired setting.
  • Cylinder functions, where line or orifice restrictions control flow-Adjust tractor flow control to point where function speed begins to decrease.
  • Auxiliary control valves (implement stack valves, row guidance)-Adjust tractor flow control to lowest setting resulting in correct operation

2. Determine total flow demand by adding flow requirements for each SCV using settings determined in Step 1. Include hitch and power beyond flow requirements, if applicable. (Refer to chart for correct settings.)

3. Determine if flow demand exceeds available pump flow. (Refer to chart for available pump flow):

  • Flow demand is less than available pump flow but there is performance concern. (See your John Deere dealer.)
  • Flow demand exceeds pump flow:
    • Increase engine rpm if possible
    • Decrease flow setting on non-critical functions
    • Convert implement open-center valves to closed-center operation, if implement is so equipped.

NOTE: Flow measurements are made without steering or hitch being used.

PUMP FLOW (APPROXIMATE)
Engine rpm Pump Flow
L/min (gpm)
800 45 (12)
1500 87 (23)
1700 98 (26)
1900 117 (31)
2100 125 (33)
2200 129 (34)

 

SCV FLOW OUTPUT (Approximate) a
SCV Flow Settings Flow
L/min (gpm)
0.1 b -
1.0 3.6 (1.0)
2.0 7.2 (1.9)
3.0 10.2 (2.7)
4.0 14.4 (3.8)
5.0 19.2 (5.0)
6.0 24.0 (6.4)
7.0 31.2 (8.2)
8.0 39.6 (10.5)
9.0 65.4 (17.2)
10.0 114.0 (30.0)
aat 2200 rpm
b0.1 = Minimum Flow Setting

 

OUO1011,0005382 -19-08SEP05-1/1