GREAT PLAINS Yield-Pro 3P3025AH, Operator'S Manual

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3P3025AH Table of Contents Index Operating Instructions
Great Plains | 411-332M | 2019-02-19 Table of Contents Index 45
Fan Circuit Operation
See also “ Fan and Adjustment ” on page 53.
Refer to Figure 46
Case Drain and Shut-off Flow
Operating Flow (Supply, Pressure)
Return Flow (Always connect sump return
hose first and disconnect last)
The three hydraulic hoses for the seed fan must be properly
connected to:
Operate seed fan in the correct direction
Operate seed fan at recommended speeds
Prevent damage the seed motor
See “ Hydraulic Hose Connections ” on page 18 for
proper hose connections.
The fan hydraulic circuit includes a check valve , which
provides a relief path for oil at motor shutoff.
If the fan is connected in reverse, flow through this valve
results in low fan rpm, providing strong indication
reversed connections.
Correct fan direction is shown at . If reversed fan is
suspected, observe it during shutoff, as the direction of
motion is easier to see at lower rpms as it slows to a stop
(initial startup is virtually instantaneous, making
observation at start difficult).
Fan speed is controlled by the tractor circuit (and not the
planter monitor - the planter monitor does report fan
rpm).
Stop the fan by setting the circuit to Neutral or Float. The
check valve slows the blades to a stop by locally
recirculating the oil.
Always start the fan with a low flow setting. Gradually
bring fan up to the recommended initial Meter
pressurization.
At excessive rpm, too much air flow can cause:
•
oil heating
•
slow lift times
If desired pressure cannot be reached, or requires
unusually high oil flow at low butterfly valve settings,
chances are the fan is running backwards. Reverse the
inlet/return lines at the hitch.
Butterfly Valve
Refer to Figure 46
This valve is used to balance air-flow between planter
sections. It is set and pinned at the factory and requires
no adjustment.
 Fan speed can change as oil heats to operating
temperature. Re-check Meter pressurization more
often during early operations.
 If the fan is connected in reverse, it may not run at all
(due to no oil source at the return connection). If oil is
present, oil bypass at the check valve prevents the
fan from reaching high rpm. A reversed fan may
send some air to the meters, but is incapable of
providing reliable air flow for planting.
Low Population Risk at Turns:
The fan requires up to 4.5 gpm. This figure does not include oil
for lift/lower or oil for marker operation. Aggressive lift/lower
operations, and simultaneous lift/marker operations, can
reduce fan rpm below that needed to pressurize meter discs.
If seed falls out of pockets, low population bands will occur
shortly after turns.
Unless the tractor has generous oil flow capacity, raise/fold
markers before lift, and lift slowly. Watch Meter pressurization
and tune operations to keep it at planting levels in turns.
Figure 46
Fan Hydraulics
38369
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Motor Seal Damage Risk:
Return hose must be attached first,
prior to inlet and return hoses being connected.
Return hose must be detached last,
to prevent damage to the fan motor.
Hydraulic Motor Performance Risk:
DO NOT connect return hose to a “power-beyond port”.
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