Fan circuit operation – Great Plains YP625PD Operator Manual User Manual
Page 33
Great Plains Manufacturing, Inc.
Operating Instructions
29
02/23/2011
401-754M
Fan Circuit Operation
See also “Fan and Adjustment” on page 41.
Refer to Figure 24
Two hydraulic hoses serve the fan, and must be properly
connected for the fan to operate in the correct
direction
, and at recommended speeds. See
“Hydraulic Hose Hookup” on page 15.
1.
Connect the motor return line
, to remote circuit
return (Extend port) or to sump.
The planter includes a pressure-relief QD coupler for
the return line. This prevents motor damage in the
event that the return line is not connected, or is
connected incorrectly; however, an oil spill results if
the return line is not correctly connected.
2.
Connect the motor inlet line
to a tractor remote
capable of 20 liters per minute. If a priority remote is
available, use it for the fan.
3.
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 connection.
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 butterfly
valve (and not the seed monitor).
You may 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.
Figure 24
Hydraulics at Fan
31869
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.
4
1
2
3
4
1
2
3
4
1
Fan speed can change as oil heats to operating
temperature. Re-check meter pressurization more often
during early operations.