GREAT PLAINS PH-15 User manual

© Copyright 2000 Printed
!Read the operator’s manual entirely. When you see this symbol, the subsequent in-
structions and warnings are serious - follow without exception. Your life and the lives of
others depend on it!
Cover illustration may show optional equipment not supplied with standard unit.
P.O. Box 5060 ●Salina, Kansas 67402-5060
Manufacturing, Inc.
148-384M
12611
Operator’s Manual
PH-15, PH-20, PFH-15 and PFH-20
Coulter Command System
5/31/2001

Table of Contents
©Copyright 2000 All rights Reserved
Great Plains Manufacturing, Inc. provides this publication “as is” without warranty of any kind, either expressedor implied. While every precaution has been taken in the preparation
of this manual, Great Plains Manufacturing, Inc. assumes no responsibility for errors or omissions. Neitheris any liability assumed for damages resultingfrom the use of the informa-
tion contained herein. Great Plains Manufacturing, Inc. reserves the right to revise and improve its products as it sees fit. This publication describes the state of this product at the
time of its publication, and may not reflect the product in the future.
Great Plains Manufacturing, Incorporated Trademarks
The following are trademarks of Great Plains Mfg., Inc.: Application Systems, Ausherman, Land Pride, Great Plains, Seed-Lok
All other brands and product names are trademarks or registered trademarks of their respective holders.
Printed in the United States of America.
Great Plains Mfg., Inc.
Table of Contents
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Important Safety Information . . . . . . . . . . . . .1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Description of Unit. . . . . . . . . . . . . . . . . . . .4
Using This Manual. . . . . . . . . . . . . . . . . . . .4
Definitions . . . . . . . . . . . . . . . . . . . . . . .4
Owner Assistance . . . . . . . . . . . . . . . . . . . .4
Section 1 Assembly and Setup. . . . . . . . . . . .5
Prestart Checklist . . . . . . . . . . . . . . . . . . . .5
Depth Sensing Wheel . . . . . . . . . . . . . . . . .5
Sensor Box . . . . . . . . . . . . . . . . . . . . . .6
Gauge Wheel Lift Cylinder . . . . . . . . . .7
Speed Sensor . . . . . . . . . . . . . . . . . . . .7
Lift Switch . . . . . . . . . . . . . . . . . . . . . . .8
Wiring Harness . . . . . . . . . . . . . . . . . . .8
Tongue Cylinder . . . . . . . . . . . . . . . . . .9
Hydraulic Control Valve. . . . . . . . . . . .10
Hydraulic Connections . . . . . . . . . . . .11
Control Box . . . . . . . . . . . . . . . . . . . . .12
Sensor Box Adjustments . . . . . . . . . . . . . .13
Section 2 Operating Instructions . . . . . . . . .14
Load Sensing Hydraulics . . . . . . . . . . . . . 14
Hydraulic Hook-Up & Function. . . . . . . . . 14
Operation of Electronic Controls. . . . . . . . 15
Field Adjustments. . . . . . . . . . . . . . . . . . . 16
Lift Switch. . . . . . . . . . . . . . . . . . . . . . 16
Speed Sensor . . . . . . . . . . . . . . . . . . 17
Hydraulic Valve . . . . . . . . . . . . . . . . . 17
Section 3 Troubleshooting. . . . . . . . . . . . . . 18
System Schematics . . . . . . . . . . . . . . . . . 20
Hydraulic Schematic . . . . . . . . . . . . . 20
Electrical Schematic. . . . . . . . . . . . . . 21
Section 4 Maintenance & Lubrication. . . . . 22
Maintenance. . . . . . . . . . . . . . . . . . . . . . . 22
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . 22
Depth Sensing Arm Wheel Pivot . . . . . . . 22
Axle Bearings . . . . . . . . . . . . . . . . . . . . . . 22
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Torque Values Chart. . . . . . . . . . . . . . . . . 23

1
Important Safety Information
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
Important Safety Information
Keep Riders
Off Machinery
Riders obstruct the operator’s view.
Riders could be struck by foreign
objects or thrown from machine.
▲Never allow riders on implement.
▲Never allow children to operate
equipment.
Be Aware of Signal Words
Signal words designate a degree or
level of hazard seriousness. The sig-
nal words are:
Indicates an imminently hazardous
situation which, if not avoided, will
result in death or serious injury. This
signal word is limited to the most
extreme situations, typically for
machine components that, for func-
tional purposes, cannot be guarded.
Indicates a potentially hazardous sit-
uation which, if not avoided, could
result in death or serious injury, and
includes hazards that are exposed
when guards are removed. It may
also be used to alert against unsafe
practices.
Indicates a potentially hazardous sit-
uation which, if not avoided, may
result in minor or moderate injury. It
may also be used to alert against
unsafe practices.
For Your Protection
▲Thoroughly read and understand
Safety Decals, page 4. Read all
instructions noted on decals.
!CAUTION
Shutdown and Storage
▲Lower machine to ground, put
tractor in park, turn off engine,
and remove key.
▲Detach and store implement in an
area where children normally do
not play. Secure implement with
blocks and supports.
OFF
!WARNING
!DANGER
!
Look for Safety Symbol
The SAFETY ALERT SYMBOL indi-
cates there is a potential hazard to
personal safety involved and extra
safety precaution must be taken.
When you see this symbol, be alert
and carefully read the message that
follows it. In addition to design and
configuration of equipment, hazard
control and accident prevention are
dependent upon the awareness, con-
cern, prudence and proper training of
personnel involved in the operation,
transport, maintenance and storage
of equipment.
Handle
Chemicals Properly
Agricultural chemicals can be dan-
gerous. Improper use can seriously
injure persons, animals, plants, soil
and property.
▲Wear protective clothing.
▲Handle all chemicals with care.
▲Follow instructions on container
label.
▲Avoid inhaling smoke from any
type of chemical fire.
▲Store or dispose of unused chem-
icals as specified by chemical
manufacturer.

2
Important Safety Information
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Transport
Machinery Safely
Maximum transport speed for imple-
ment is 20 mph. Some rough terrains
require a slower speed. Sudden
braking can cause a towed load to
swerve and upset.
▲Do not exceed 20 mph. Never
travel at a speed which does not
allow adequate control of steering
and stopping. Reduce speed if
towed load is not equipped with
brakes.
▲Comply with state and local laws.
▲Do not tow an implement that,
when fully loaded, weighs more
than 1.5 times the weight of tow-
ing vehicle.
Use Safety
Lights and Devices
Slow-moving tractors, self-propelled
equipment and towed implements
can create a hazard when driven on
public roads. They are difficult to see,
especially at night.
▲Use flashing warning lights and
turn signals whenever driving on
public roads.
▲Use lights and devices provided
with implement.
Practice Safe Maintenance
▲Understand procedure before
doing work. Use proper tools and
equipment. Refer to this manual
for additional information.
▲Work in a clean, dry area.
▲Lower implement to ground, put
tractor in park, turn off engine,
and remove key before performing
maintenance.
▲Allow implement to cool completely.
▲Inspect all parts. Make sure parts
are in good condition and installed
properly.
▲Remove buildup of grease, oil or
debris.
▲Remove all tools and unused
parts from implement before oper-
ation.
Use A Safety Chain
▲Use a safety chain to help con-
trol drawn machinery should it
separate from tractor drawbar.
▲Use a chain with a strength rat-
ing equal to or greater than the
gross weight of towed machin-
ery.
▲Attach chain to tractor drawbar
support or other specified
anchor location. Allow only
enough slack in chain to permit
turning.
▲Replace chain if any links or end
fittings are broken, stretched or
damaged.
▲Do not use safety
chain for towing.

3
Important Safety Information
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
Prepare for Emergencies
▲Be prepared if a fire starts.
▲Keep a first aid kit and fire extin-
guisher handy.
▲Keep emergency numbers for
doctor, ambulance, hospital and
fire department near phone.
Tire Safety
Tire changing can be dangerous and
should be performed by trained per-
sonnel using correct tools and equip-
ment.
▲When inflating tires, use a clip-on
chuck and extension hose long
enough to allow you to stand to
one side–not in front of or over tire
assembly. Use a safety cage if
available.
▲When removing and installing
wheels, use wheel-handling
equipment adequate for weight
involved.
911
Wear
Protective Equipment
▲Wear protective clothing and
equipment.
▲Wear clothing and equipment
appropriate for the job. Avoid
loose-fitting clothing.
▲Because prolonged exposure to
loud noise can cause hearing
impairment or hearing loss, wear
suitable hearing protection such
as earmuffs or earplugs.
▲Because operating equipment
safely requires your full attention,
avoid wearing radio headphones
while operating machinery.
Avoid High
Pressure Fluids Hazard
Escaping fluid under pressure can
penetrate skin, causing serious
injury.
▲Avoid the hazard by relieving
pressure before disconnecting
hydraulic lines.
▲Use a piece of paper or card-
board, NOT BODY PARTS, to
check for suspected leaks.
▲Wear protective gloves and safety
glasses or goggles when working
with hydraulic systems.
▲If an accident occurs, see a doc-
tor immediately. Any fluid injected
into the skin must be surgically
removed within a few hours or
gangrene may result.
Safety at All Times
Thoroughly read and understand this
manual before operating implement.
Refer to Safety Decals, page 4. Read
all instructions noted on decals.
▲Be familiar with all implement
functions.
▲Operate implement from driver’s
seat only.
▲Do not leave tractor or implement
unattended with engine running.
▲Do not dismount a moving tractor.
Dismounting a moving tractor could
cause serious injury or death.
▲Do not stand between the tractor
and implement during hitching.
▲Keep hands, feet and clothing
away from power-driven parts.
▲Wear snug-fitting clothing to avoid
entanglement with moving parts.
▲Watch out for wires, trees, etc.,
when raising implement. Make
sure all persons are clear of work-
ing area.
▲Do not turn tractor too tight, caus-
ing implement to ride up on
wheels.

4
Introduction
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Introduction
Owner Assistance
If you need customer service or repair parts, contact a
Great Plains dealer. They have trained personnel, repair
parts and equipment specially designed for Great Plains
products.
Your machine’s parts were specially designed and should
only be replaced with Great Plains parts. Always use the
serial and model number when ordering parts from your
Great Plains dealer.
Your Great Plains dealer wants you to be satisfied with
your new machine. If you do not understand any part of
this manual or are not satisfied with the service received,
please take the following actions.
1. Discuss the matter with your dealership service man-
ager. Make sure they are aware of any problems so
they can assist you.
2. If you are still unsatisfied, seek out the owner or gen-
eral manager of the dealership.
3. For further assistance write to:
Product Support
Great Plains Mfg. Inc., Service Department
PO Box 5060
Salina, KS 67402-5060
Great Plains welcomes you to its growing family of new
product owners. This implement has been designed with
care and built by skilled workers using quality materials.
Proper setup, maintenance and safe operating practices
will help you get years of satisfactory use from the ma-
chine.
Description of Unit
The Precision Hitch Coulter Command System couples a
microprocessor with electro-hydraulics to provide a state-
of-the-art system for maintaining coulter depth regardless
of the terrain or soil type. It also provides coulter depth ad-
justment from the tractor cab.
The Coulter Command System contains a depth sensing
wheel, an electronic control box, a speed sensor, a depth
sensorbox,aliftcontrolswitch,awiringharness,atoplink
and a hydraulic control valve. It uses the tongue cylinder
from your Precision Hitch.
This manual applies to the following:
•148-382A Precision Hitch Coulter Command,
Non Fertilizer
•148-383A Precision Hitch Coulter Command, For
Fertilizer
Referto thePrecisionHitch operator’s manualfordetailed
informationonsafelyoperating,adjusting,troubleshooting
and maintaining the Precision Hitch. Refer to the parts
manual for Coulter Command part identification.
•148-365M PH-15, PH-20, PFH-15 and PFH-20
Operator’s Manual
•148-365P PH-15, PH-20, PFH-15 and PFH-20
Parts Manual
Using This Manual
This manual will familiarize you with safety, assembly, op-
eration, adjustments, troubleshooting and maintenance.
Readthismanualand followtherecommendationstohelp
ensure safe and efficient operation.
Theinformation in thismanual is currentat printing.Some
parts may change to assure top performance.
Definitions
The following terms are used throughout this manual.
Right-handand left-handasused inthis manual aredeter-
mined by facing the direction the machine will travel while
in use unless otherwise stated.
NOTE: Useful information related to the preceding topic.
IMPORTANT: A crucial point of information related to
the preceding topic. For safe and correct operation,
read and follow the directions provided before continu-
ing.

5
Section 1 Assembly and Setup
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
Section 1 Assembly and Setup
Prestart Checklist
Depth Sensing Wheel
If your Precision Hitch is equipped with liquid fertilizer
(PFH), the fertilizer drive wheel doubles as the coulter
depth sensing wheel and will require additional sensor as-
sembly and adjustment.
If you do not have the liquid fertilizer option (PFH), the
coulter command will contain a coulter depth sensing
wheel which is subassembled and preadjusted.
Check
All major frame components
Fasteners and pins that were shipped with the Coulter Com-
mand System.
NOTE: All hardware from the factory has been installed in the
location where it will be used. If a part or fastener is temporarily
removed for assembly reasons, remember where it goes.Keep
the parts separated.
Have a minimum of 2 people at hand while assembling the
Coulter Command System.
Have a forklift or loader along with chains and safety stands
ready for the assembly task.
If you are unsure where a fastener is used, refer to the Parts
Manual to identify it.
Figure 1-1
Depth Sensing Wheel 18439
See Figure 1-1.
Installthecoulterdepth sensing wheelassembly(1)tothe
front 4” x 4” coulter tool bar tube with the two 5/8 x 6 inch
u-bolts (2), lock washers (3) and nuts (4).
Position the center of the coulter depth sensing wheel
mount bracket 2 1/4 inches to the right of the center of the
Precision Hitch beam. This will leave about 2 3/4 inch
clearancebetweentheinsideofthedepthsensingtireand
the edge of the hitch center beam.

6
Section 1 Assembly and Setup
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
5. Slide bearing and sensor mount plate subassembly
oversensorspindle(1),andboltsensormountplateto
drive wheel mount bracket with 1/2 x 1 1/2 inch bolts
(18), lock washers (19) and nuts (20).
6. Place circular disk (13) over threaded end of sensor
spindle (1) and install a 3/8 inch washer (21) and
flange nut (22). Do not tighten flange nut at this time.
7. With the circular disk in place, slide the sensor mount
plate subassembly in or out until the vertical flat bar
link (15) and the circular disk are aligned.
8. Tighten two set screws on the bearing (4) to hold the
subassembly in place.
9. Tighten the flangette bolts (7) being careful not to
damage the internal linkages.
10. Set sensor box cover and cover screws aside and
continue with speed sensor assembly.
Figure 1-2
Sensor Box 18427
Sensor Box
Ifthesensorboxis not preassembledtothedepthsensing
wheel, refer to Figure 1-2 and the following instructions.
1. Assemble sensor spindle (1) to left end of fertilizer
drivewheelrockshaftwiththree1/4x3/4 inchbolts(2)
and lock washers (3).
2. Bolt the bearing (4) between twoflangettes (5) and to
thebacksideof thesensormount plate(6)with 5/16x
3/4 inch carriage bolts (7), lock washers (8) and nuts
(9). Do not tighten nuts at this time.
NOTE: Position the heads of the bolts against the
flangettes with lock washers and nuts pointing outward.
Locking collar on bearing should point away from the sen-
sor mount plate and toward the coulter depth sensing
wheel.
3. Place rubber gasket (10) between sensor box (11)
and the sensor mount plate (6). Screw sensor box to
sensor mount plate with #10 x 7/16 inch pan head
screws (12) and star lock washers (13).
4. Remove cover from sensor box and inspect the inter-
nal linkages. The circular disk (14) should be linked to
the flat bar (15) with a formed round bar link (16).
Make sure the round bar link is in place and secured
witha springclip extensionspring (17)thatis connect-
ed between the circular disk and the flat bar through
the small holes.

7
Section 1 Assembly and Setup
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
Figure 1-4
Gauge Wheel Lift Cylinder 18429
Gauge Wheel Lift Cylinder
Refer to Figure 1-3.
1. Install the base end of the lift cylinder (1) to gauge
wheel mount bracket with a 1/2 x 1 3/4 inch clevis pin
(2) and a 1/8 x 3/4 inch cotter pin (3) provided with the
cylinder.
NOTE: The ports on the cylinder should point away from
the depth sensing gauge wheel.
2. Place the rod end of the lift cylinder between the slot-
ted lugs on the gauge wheel arm. Place a flat washer
(4) on the outside of each slotted lug on the gauge
wheel arm. Pin in place with a 1 1/2 x 2 3/4 inch clevis
pin (5) and a 1/8 x 3/4 inch cotter pin (3).
Figure 1-3
Gauge Wheel Lift Cylinder
18428
Speed Sensor
Refer to Figure 1-4.
1. Removethetireandrim fromthedepthsensingwheel
andboltthespeedsensorplate(1)betweenthewheel
and rim.
2. Screw the speed sensor (2) to the sensor mounting
bracket at bottom of the gauge wheel with #6 x 1/2
inch pan head screws (3), lock washers (4) and flat
washers (5).
3. Position sensor to just touch the speed sensor plate
(1) and tighten screws.
4. Route co-axial cable (6) from sensor, across gauge
wheel arms, and up the side opposite the tire.
5. Screwtheendfittingintotheco-axconnectorontopof
the sensor box (7).
6. Slide co-axial cable into notches at the bottom of
gauge wheel arms and fasten to the side of gauge
wheel arm with the cable tie mounts (8) and cable ties
(9). Make sure the cable does not rub anything as
depth sensing wheel moves up and down.

8
Section 1 Assembly and Setup
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Wiring Harness
Refer to Figure 1-5.
1. Route the wiring harness (7) through 8 x 8 inch hitch
tube and to the lift switch at the rear of the machine.
Plug into the lift switch and support the cable with ca-
ble tie mounts (8) and cable ties (9) or strap the cable
to the hydraulic hoses.
2. Plug the 4-pin connector of the wiring harness to sen-
sor box on the depth sensing wheel and support the
cable with cable mounts and ties.
3. Route the 9-pin connector through the spring hose
loop and to the tractor hitch. This will plug into the 9-
pin female connector from the control box extension
cable.
4. Plugtheotherthreeshortleadsintotheleadsfromthe
solenoids on the hydraulic control valves (10 and 11)
after they are installed.
Figure 1-5
Lift Switch and Wiring Harness 18430
Lift Switch
Refer to Figure 1-5.
1. Bolt the plunger activated lift switch (1) to the switch
mount located next to the left transport lift cylinder at
rear of the Precision Hitch transport frame with two
#10 x 3/4 inch pan head screws (2), flat washers (3),
lockwashers(4)andnuts(5).Donottightenscrewsat
this time.
2. Fasten rockshaftswitchcam(6) totransportrockshaft
just below the lift switch. Position the cam so it con-
tacts the lift switch when hitch is raised and moves
away from the lift switch when hitch is lowered. Posi-
tion the worm gear screw on the cam mounting band
to the bottom of the rockshaft so it does not interfere
with the lift switch.
3. Adjust lift switch in the slotted holes so the plunger
movesin about1/8inch when thecamactivatesit and
tighten the #10 screws. Do not bottom out the plunger
on the lift switch.
4. Rotate the cam assembly so it hits the plunger when
the hitch is raised just enough to begin to pick the
openers off the ground.

9
Section 1 Assembly and Setup
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
5. Remove elbow fitting (8) at base end of tongue cylin-
der and screw the 1/16 inch orifice plate (9) into base
end port. Screw orifice plate in far enough so it does
not interfere with elbow fitting.
6. Replace fitting.
IMPORTANT: Failure to install the orifice plate will not al-
low Coulter Command to operate correctly.
Figure 1-6
Tongue Cylinder 18432
Tongue Cylinder
Refer to Figure 1-6.
1. Remove stroke pointer gauge (1) at the rod end of the
tongue cylinder. Retorque cylinder tie rod bolts to 95
ft-lbs.
2. Remove stroke pointer (2) at cylinder rod clevis.
3. Turntonguecylinderwithrodendpointingforwardand
down and with ports turned up. Use clevis pin (3), flat
washer (4) and cotter pin (5) to replace stroke pointer
pin at what is now the base end of the cylinder.
4. Connect rod end to tongue with clevis pin (6) and hair
pin cotter (7).

10
Section 1 Assembly and Setup
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Figure 1-7
Hydraulic Control Valve 19361
Hydraulic Control Valve
Refer to Figure 1-7.
1. Bolt the electronic depth control valve (1) to the top of
thevalvemountbracket(2)with5/16x4 inchbolts(3),
lock washers (4) and hex nuts (5). Position valve so
solenoids set above the middle of the top surface of
valve mount.
2. Bolt the lift circuit manifold (6) to the side of the valve
mount bracket with 5/16 x 4 inch bolts (7), lock wash-
ers (4) and hex nuts (5). Position valve so the four
portspointawayfromvalvemountandsolenoidpoints
up.
3. Attach the valve mount to the Precision Hitch with 1/2
x 5 1/2 inch bolt (8), lock washer (9) and hex nut (10).
Assemble the bolt through the pivot tube (11) located
behind the tongue cylinder. Position valve mount so
dual solenoids face toward rear of machine.

11
Section 1 Assembly and Setup
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
9. Connect a 36 inch long hose (10) to port “C1” of the
lower valve and the elbow on the base end of the
gauge wheel lift cylinder.
10. Connect a 36 inch long hose (10) to port “C2” of the
lowervalveandthe elbowon therodend ofthegauge
wheel lift cylinder.
11. Remove the plug from the top of the lower valve at the
port labeled “M4” and replace it with the relief car-
tridge (11). Torque the cartridge to 30 ft-lbs.
12. Removethe reliefvalveandmount (9)which ismount-
ed to the tongue tube by removing the 3/8 inch u-bolt.
Discard the relief valve and its mount.
13. Route the three wiring harness leads, mentioned on
page 8, step 4, under the valve mount.
14. Plug lead “A” into solenoid “A”.
15. Plug lead “B” into solenoid “B”.
16. Plug lead “S1” into solenoid “S1”.
Figure 1-8
Hydraulic Connections 19360
Hydraulic Connections
Refer to Figure 1-8.
1. On the top valve assemble the 3/4 elbows (1) to valve
portsmarked“P” and “T” and the3/4straightadapters
(2) to valve ports marked “A” and “B”.
2. Onthe lowervalveassemblethe3/4 straightadapters
(2) to valve ports marked“V1” and “V2” and the 3/4 el-
bows (1) to valve ports marked “C3” and “C4”.
3. Assemble the 9/16 elbows (3) to valve ports marked
“C1” and “C2” of the lower valve.
4. Assemble the remaining two 9/16 elbows (3) to the
ports on the side of the gauge wheel lift cylinder (4).
5. Removehoses(5)fromtonguecylinderandassemble
them to the elbows at parts “P” and “T” on the top
valve.
6. Connect the 20 inch long hose (6) between port “B” of
the top valve and the tongue cylinder base end fitting.
7. Connect the 30 inch long hose (7) between port “A” of
the top valve and the tongue cylinder rod end fitting.
8. Remove hoses (8) from the front side of the relief
valve (9) which is mounted on the tongue tube and as-
semble them to the elbows at ports “C3” and “C4” on
the lower valve.
NOTE: The hose coming from the base end of the trans-
port lift cylinders connects to port “C3”. The hose coming
from the rod end of the transport lift cylinders connects to
port “C4”.

12
Section 1 Assembly and Setup
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Control Box
1. Mount the control box, Figure 1-9, at a convenient lo-
cationinthe tractorcab.Connect the 12’extensionca-
ble to the 9-pin connector on the back of the control
box and route the cable back toward the tractor draw-
bar area making sure it will not get kinkedor pinched.
2. Connect the power cord to a good uninterrupted 12
voltpowersourceonthetractor.Connectingdirectlyto
the battery is recommended. Plug the cord into the
lead with the 2-Pin connector on the back of the con-
trol box. The polarity of the power supply is very im-
portant to prevent circuit damage. The white wire of
the power cord must be connected to the "+" positive
battery terminal and the black wire to the "-" negative
battery terminal.
Figure 1-9
Control Box
12575

13
Section 1 Assembly and Setup
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
decreases the voltage potential.
2. The second means of adjusting the linkage inside the
sensor box involves measuring from the inside edge
ofthe boxto the leftpivotofthe formed round-barlink.
Thedepthsensingwheelshouldbeoffthegroundand
rotated down as far as its spring-loaded down-pres-
sure link will allow. Remove the cover from the sensor
box and inspect the internal linkage for proper assem-
bly as shown in Figure 1-10.
With the depth sensing wheel in the max down posi-
tion,thepivotbetweentheverticalflat-bar linkandthe
formed round-bar link should be 15/16 inch from the
front inside edge of the sensor box.
Withthesensorboxlinkageproperlyassembled,loos-
en the 3/8 inch hex flange nut on the sensor spindle
and rotate the circular disk until the pivot between the
vertical flat-bar link and the formed round-bar link is
15/16inch+or-1/16inchfromthefrontinsideedgeof
the box. Be careful not to rotate the circular disk as
you retighten the nut. Replace the sensor box cover.
Once the voltage potential reads 5 volts DC, + or - 1/4
volt,tighten the 3/8 inch flange nut. Be careful not to ro-
tatethecirculardiskasyoutightenthenut.Replace the
sensor box cover.
Some models of the sensor box have a mark on the
vertical flat-bar link which should line up with a mark
on the link’s slotted mount plate at the correct preset
voltage. With the depth sensing wheel in the max
downposition,themarksshould line up at a voltageof
5 volts DC + or - 1/4 volt. Aligning the marks is more
accuratethan relying onthe 15/16 inchmeasurement.
Figure 1-10
Sensor Box Adjustments
12619
Sensor Box Adjustments
Refer to Figure 1-10.
Coulter command depth sensing wheel assemblies which
are preassembled at the factory are preadjusted and
should not require further adjustment. If the sensor box at
the depth sensing wheel has been field installed, or if its
linkage gets out of adjustment, it must be adjusted using
one of the following two procedures:
1. The best and most accurate means of adjusting the
linkage inside the sensor box makes use of a voltme-
ter which reads 0-12 volts DC. The Control Box in the
tractor must be properly connected to a power source
and the POWER switch must be ON. The TONGUE
HYDRAULICS switch should be in the MANUAL
mode. The wiring harness must be connected to the
control box and the sensor box. The depth sensing
wheel should be off the ground with the arm rotated
down as far as its spring-loaded down-pressure link
will allow. Remove the cover from the sensor box and
inspect the internal linkage for proper assembly as
shown in Figure 1-10.
With the depth sensing wheel in the max down posi-
tion,the voltagepotential betweentheleadcontaining
theWHITEWIREandthegroundlead(BLACKWIRE)
in the gauge wheel sensor box (#1) should be 5 volts
DC plus or minus 1/4 volt. To adjust the gauge wheel
sensor box linkage, loosen the 3/8 inch hex flange nut
(#2) on the sensor spindle and rotate the circular disk
(#3) until the voltage potential between the lead con-
tainingtheWHITEWIREandthegroundlead(BLACK
WIRE) (#1) is 5 volts DC plus or minus 1/4 volt. Rotat-
ing the circular disk counterclockwise increases volt-
age potential, and rotating the circular disk clockwise

14
Section 2 Operating Instructions
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
The Coulter Command couples a microprocessor with
electro-hydraulics to provide a state-of-the-art system for
maintaining coulter depth regardless of the terrain or soil
type. It also provides coulter depth adjustment from the
tractor cab. A manual feature allows manual control of the
front hydraulic tongue cylinder for hitching, unhitching, or
making adjustments. To understand the Coulter Com-
mand system, one must be familiar with the functions of
the Hydraulics and the Electronic controls.
Load Sensing Hydraulics
To operate Coulter Command, some tractors with load-
sensing or constant-flow hydraulics require a bypass
valve, Great Plains part number 810-400C. Contact your
Great Plains dealer to order the bypass valve.
After installing the bypass valve, set valve as follows:
1. Close bypass valve for no oil flow by turning knob (1)
on valve clockwise. See Figure 2-1.
Figure 2-1
Bypass Valve
2. Adjust flow-control valve for tractor to a maximum of
10 gpm. If you do not have a flowmeter, hook a stan-
dard 8-inch stroke, 4-inch bore cylinder to the circuit.
At 10 gpm, the cylinder will take about 2.6 seconds to
extend.
3. Engage tractor hydraulics for Coulter Command.
4. Using a pressure gauge, turn knob on bypass valve
counterclockwise until pressure gauges reads 1800
psi. Lock bypass valve at this setting.
NOTE: Failure to install a bypass valve on load-sens-
ingtractorsmaycausemajor tractor damage.Consult
yourtractor dealer toverifyif thebypassvalveis need-
ed.
17987
Hydraulic Hook-Up & Function
Tractors with closed-center hydraulic systems and
variable displacement hydraulic pumps.
(If you are not familiar with your tractor's hydraulics, con-
sult your tractor dealer.)
Fortractorswithclosed-centerhydraulicsorpressure/flow
compensated hydraulics which are powered by a variable
displacement hydraulic pump, turn the knurled control
knob on the left side of the hydraulic valve completely
clockwiseandlockit inplace with thecircular lockdisk.Do
notapplyanytorquetothecontrolknobafteritbottomsout
or valve damage may occur. Be sure the lock disk is
snuggedtopreventthecontrolknobfromvibratingloosein
field operation.
Thetongue cylinderhydrauliccircuit consistsof thehoses
from ports "P" and "T". Once the hydraulic valve is set for
CLOSED CENTER operation, the Coulter Command
tongue cylinder circuit requires live hydraulic power sup-
plied to the port labeled "P". This is accomplished by
pushing FORWARD on the tractor remote hydraulic lever
and LOCKING IT OPEN in this position.
•OnJohnDeeretractorsequippedwithSOUND-GUARD
R Body you must use the LEVER LOCK CLIP John
Deere Part No. R52667 to lock the lever in the forward
position.See your tractordealerfor purchase andinstal-
lation of this clip.
•OnJohnDeere 7000 Series tractors, rotate valve detent
selector to MOTOR POSITION to lock the lever in the
forward position.
•On Case-IH Magnum tractors use the circuit designed
for HYDRAULIC MOTOR CONTROL and lock the lever
forward in the detent position. The detent pressure will
probably have to be turned up to its maximum setting.
DO NOT tie the hydraulic lever on past the detent posi-
tionwith a strap.Thiscould shift thespoolbeyond its de-
signed operating position and cause system damage.
See your tractor dealer for hydraulic system details.
•On other model tractors use the circuit designed for HY-
DRAULIC MOTOR CONTROL and lock the lever for-
ward in the detent position. The detent pressure will
probably have to be turned up to its maximum setting or
some other mechanical detent holder will have to be
used to hold the lever forward. See your tractor dealer
for the proper means of providing constant pressure/
flow to the tongue cylinder circuit.
The Coulter Command hydraulic circuit requires a flow
rateof8to12gallonsperminuteforefficientoperation.On
high flow rate tractors, the flow control on the tractor re-
mote may have to be turned down so as not to exceed 12
gallons per minute. Flow rates higher than 12 gallons per
minute will not damage the valve, but may cause poor
Coulter Command performance.
The remote tractor hydraulic lever will have to be locked in
Section 2 Operating Instructions

15
Section 2 Operating Instructions
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
positionto supplyoilto the"P"port ofthe hydrauliccontrol
valve, regardless of whether you want to control the
tongue hydraulic cylinder manually or automatically.
ThePrecisionHitchtransporthydrauliccircuitcontainsthe
hoses from the ports marked "V1" and "V2". This circuit
mustbe connectedtoone of theremaining circuitsforrais-
ingandloweringthetransportsystem. This circuitmustre-
ceive hydraulic pressure for raising the machine even
while the hydraulic tongue circuit is "locked in" for continu-
ous use. If the machine will not raise when the hydraulic
tongue circuit is "locked in," consult your tractor dealer.
You may need to run the transport hydraulic circuit on a
"priority circuit" and the hydraulic tongue circuit on an al-
ternateremoteifthetractorhydraulicsallowslivehydraulic
power to other remotes. If the "priority circuit" is the only
circuit suitable for HYDRAULIC MOTOR CONTROL, then
run the transport hydraulic circuit on the "priority circuit"
andrunthehydraulictonguecircuitonanalternateremote
with the Coulter Command valve in the OPEN CENTER
MODE.
Tractors with open center hydraulic systems or fixed
displacement hydraulic pumps.
(If you are not familiar with your tractor's hydraulics, con-
sult your tractor dealer.)
Fortractorswithopen-centerhydraulicsorontractorswith
fixed displacement hydraulic pumps turn the knurled con-
trol knob on the left side of the hydraulic valve completely
counterclockwise and lock it in place with the circular lock
disk. Be sure the lock disk is snugged to prevent the con-
trol knob from vibrating loose in field operation.
ThePrecisionHitchtransporthydrauliccircuitcontainsthe
hoses from the ports marked "V1" and "V2". This circuit
must be connected to tractor's "priority circuit" to supply
hydraulic pressure for raising the machine even while the
hydraulic tongue circuit is "locked in" for continuous use.
The "No.1" hydraulic circuit on most open-center tractors
is the priority circuit.
Thetongue cylinderhydrauliccircuit consistsof thehoses
fromports "P"and "T". Connect"P" and "T"to a circuitoth-
erthan the"prioritycircuit". Once thehydraulicvalveis set
for OPEN CENTER operation, the Coulter Command
tongue cylinder circuit requires live hydraulic power sup-
pliedtotheportlabeled "P". This isaccomplishedbypush-
ing FORWARD on the tractor remote hydraulic lever and
LOCKING IT OPEN in this position. The remote tractor hy-
draulic lever will have to be locked in position to supply oil
to the "P" port of the hydraulic control valve, regardless of
whether you want to control the tongue hydraulic cylinder
manually or automatically.
The Coulter Command tongue hydraulic circuit requires a
flow rate of 8 to 12 gallons per minute for efficient opera-
tion. On high flow rate tractors, turn down the flow rate on
the tractor remote, if possible, so as not to exceed 12 gal-
lons per minute. Flow rates higher than 12 gallons per
minute will increase the heat generated by the Coulter
Command circuit when it circulates this high flow of oil.
When operating the Coulter Command tongue hydraulic
circuit in the OPEN CENTER mode, use poppet style
quick couplers on the hoses connecting to the tractor.
These quick couplers allow better flow through some trac-
tor remotes and may produce less heat when circulating
continuous hydraulic flow through them. Parker Hannifin
offers the poppet style Pioneer quick coupler in their 8010
Series couplers. For tractors with Pioneer quick couplers
use Pioneer 8010-4P poppet style male couplers when
operating in the OPEN CENTER mode. See Figure 2-2.
Figure 2-2
Quick Couplers
Operation of Electronic Controls
1. Connect power cord to an uninterrupted, 12-volt pow-
er source on tractor. Connecting directly to battery is
recommended. Plug cord into lead with two-pin con-
nector on back of control box. The polarity of the pow-
er supply is very important to prevent circuit damage.
The white wire of the power cord must be connected
to the "+" positive battery terminal and the black wire
to the "-" negative battery terminal.
2. Connect the control box cable to the back of the con-
trol box and route it out of the tractor. Connect it to the
hitch wiring harness.
3. With the remote tractor hydraulic lever locked in posi-
tionto supplyoil tothe "P" portof thehydrauliccontrol
valve, turn the power switch on.
a. For manual tongue hydraulic cylinder operation,
simply move the UP-DOWN switch the desired di-
rection. Moving the switch to the UP position ex-
tends the tongue cylinder, and moving the switch
to the DOWN position retracts the tongue cylin-
der. If UP retracts the cylinder, then your remote
hydraulicleverisnotsupplyingoiltothe"P"portof
the hydraulic control valve, or the wires going to
the solenoids are reversed. By moving the UP-
DOWN switch, the AUTO-MANUAL switch auto-
matically switches to the MANUAL mode. If you
want to manually hold the tongue hydraulic cylin-
der in the position set by the automatic controls
without moving it, just switch the AUTO-MANUAL
switch to MANUAL.
b. Forautomatic coulterdepthcontrol, simplyswitch
the AUTO-MANUAL switch to AUTO and dial in
the desired coulter depth you wish to maintain
withthecoulterdepthcontrolknob.(Themarkings
onthe knobsettings areforreferenceonlyand do
not represent a depth measurement.)
Poppet Style Ball Style 16316

16
Section 2 Operating Instructions
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
!WARNING
Make sure all people, animals, and objects are clear of the
coulter tool bar before switching the tongue hydraulics to the
AUTO mode.
Turning the coulter depth switch clockwise makes the
coulters run shallower, and turning the coulter depth
switchcounterclockwisemakesthe coultersrun deeper. If
the Precision Hitch is not moving or is on a hard surface,
turning the coulter depth switch may not cause thetongue
cylindertoretracttothedesiredposition.Thecoultersmay
notpenetrateto thedesired depthuntil the PrecisionHitch
is moving. A pulsing of the valve may be the only reaction
when adjusting the COULTER DEPTH knob on a station-
ary machine. The coulter depth setting can always be
changed "on-the-go" if you desire.
With the AUTO-MANUAL switch in the AUTO mode, the
coulters will always maintain a consistent depth regard-
less of terrain, soil type or speed. When lifting and turning
in the field, the tongue cylinder will remain in its last auto-
matically set mid stroke position. When the machine is
lowered, the coulters will automatically return to their pre-
set depth.
Field Adjustments
Lift Switch
Referto Figure 2-3.The switchat therear of thePrecision
Hitch determines the point in the lift cycle at which the au-
tomatic feature of the Coulter Command will be interrupt-
ed and the depth sensing gauge wheel will be lifted off the
groundforturning around. Sincethe Precision Hitchtrans-
port tires can be lowered during operation to provide flota-
tion for the drill or planter in soft soil conditions, coulter
command should not be interrupted, and the depth sens-
ing gauge wheel should not be lifted until after the trans-
porttiresareloweredtothepointwhere theyarenolonger
usedforsystemflotation. Thisis usually thepoint inthe lift
cycle when the drill or planter openers are just being lifted
out of the ground.
Acamfastenedto therockshaftactivatesa plungerswitch
which causes the automatic feature of the Coulter Com-
mand to be interrupted and the depth sensing gauge
wheel to be lifted off the ground for turning the Precision
Hitch around in the field.
1. To properly adjust the lift switch timing, loosen and ro-
tate the cam assembly so it hits the plunger roller of
the lift switch when the Precision Hitch is raised just
enoughtobeginto pickthe openersout ofthe ground.
BE CAREFUL NOT TO "BOTTOM OUT" THE LIFT
SWITCH PLUNGER when the plunger roller climbs
the surface of the cam. Tighten the cam onto the rock-
shaft.
2. To adjust the lift switch position loosen the two #10
screws and slide it up or down in the slotted switch
mount holes so the plunger moves in only about
1/8 inch when the cam activates it. DO NOT "BOT-
TOM OUT" THE LIFT SWITCH PLUNGER.
Lift Switch Field Adjustments
Figure 2-3 12681

17
Section 2 Operating Instructions
6/21/2004 PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M
Great Plains Mfg., Inc.
!WARNING
Shut the tractor off and put all hydraulic valve levers in neutral
position before attempting to work on or crawl under the ma-
chine. Do not crawl under a raised machine without the trans-
port locks securely in place. Sudden hydraulic activation or
failure could cause serious injury or death.
Aproperlyadjusted liftswitchallows the automaticcoulter
depth feature to be interrupted early in the lift cycle. This
providesthe fastestlift cycle timeswhen turning aroundin
thefield. Operating the liftswitchearlyinthe liftcycle,also
provides the maximum amount of time for the depth sens-
ing gauge wheel cylinder to completely extend as the ma-
chine is lowered back to field position. It is important that
thedepthsensinggaugewheelcylinderalwaysbefullyex-
tendedwhen thePrecisionHitchisinfieldpositiontoallow
the depth sensing gauge wheel to float through its full
range of motion.
Speed Sensor
The Coulter Command depth control system automatically
compensates for changes in ground speed. A speed sen-
sor and speed sensor plate mounted behind the coulter
depth sensing wheel monitors the ground speed so the
Coulter Command can adjust for it. This sensor should be
in close proximity to the speed sensor plate. In general, it
should never need adjustment. If the sensor does get
moved, it should be adjusted against the speed sensor
plate until it just touches the plate in the closest part of the
rotation. A bent speed sensor plate should be straight-
enedorreplacedimmediately.Toadjustthespeedsensor,
loosenthetwo#6 screwson the sensorand slideittoward
thespeed sensor plate.Rotatethedepthsensingwheelto
theposition wherethe speed sensor plate isclosest tothe
sensor mount, and retighten the sensor mount screws
where the sensor just touches the speed sensor plate.
Hydraulic Valve
All adjustable valve cartridges on the hydraulic valve
blocks are preset at the manufacturer and should not be
tampered with. Tampering with a cartridge valve could re-
sult severe frame damage to the Precision Hitch.
The only required adjustment is on the upper hydraulic
control valve. This valve contains a rotary knob for setting
the Coulter Command to be used with either OPEN CEN-
TERED or CLOSED CENTERED tractor hydraulics.
Check the owners manual of your tractor to determine
what type of hydraulic system you have.
Refer to “Hydraulic Hook-Up & Function” on page 14 of
this manual for setting the hydraulic control valve for your
style of tractor.

18
Section 3 Troubleshooting
PH-15, PH-20, PFH-15 and PFH-20 Coulter Command System 148-384M 6/21/2004
Great Plains Mfg., Inc.
Problem Possible Cause Solution
Coulters move up when the
down switch is operated and
down when the up switch is
operated.
Not supplying oil to the "P" port of the
hydraulic valve. Reverse the remote hydraulic lever in the tractor.
Solenoids wired backward or hoses from
port "A" and port "B" reversed at the
hydraulic valve.
Unplug solenoids and swap wire leads to
them.
Automatic Coulter depth con-
trol stops adjusting coulter
depth
TONGUE HYDRAULICS switch bumped to
MANUAL mode. Flip TONGUE HYDRAULICS switch back to AUTO mode
Tractor remote hydraulic lever not locked for
constant oil supply to valve. Lock Tractor remote hydraulic lever with rubber tarp strap or other means.
System variables out of adjustment Turn power switch OFF and back on again
so system variables can reset. Then flip the
AUTO-MANUAL switch to AUTO and
resume operation.
TurningtheCOULTERDEPTH
knob does not set coulters
deep enough.
If the tongue cylinder runs completely
retracted, the tractor drawbar is to high. Use a straight drawbar or one which sweeps down.
If in extremely hard conditions with the
machine standing the tongue cylinder
pulses but does not retract.
This is perfectly normal. The cylinder will
not penetrate the coulters on a stationary
machine in hard conditions. Pull forward
and check coulter depth on a moving
machine.
If the COULTER DEPTH knob is turned to
"A" and the tongue cylinder will not com-
pletely retract when moving through the
field then the internal sensor box linkage is
not set correctly.
Adjust the sensor box internal linkage. See
"Sensor Box Adjustments" on page 13.
If the sensor box linkage is properly
adjusted and tongue cylinder constantly
pulses while moving through the field but
the front tongue cylinder will not retract, you
do not have enough system weight.
Add fertilizer or water to liquid tanks. Add
tool bar weight brackets to coulter tool bars.
The hydraulic valve con-
stantly pulses when you are
stopped to refill or adjust
something.
Hard soil conditions are hindering coulter
penetration while stopped. Flip TONGUE HYDRAULICS switch to MANUAL mode while you are stopped or
turn coulter command power OFF. Pulsing
does not hurt the valve, but can be annoy-
ing.
TurningtheCOULTERDEPTH
switch to "E" does not allow
the coulters to run shallow
enough.
The internal sensor box linkage is not set
correctly. Adjust the sensor box internal linkage. See "Sensor Box Adjustments" on page 13.
Depth sensing gauge wheel
notliftingoffthegroundwhen
Precision Hitch is raised.
Coulter Command power is OFF or 12 volt
power has been interrupted. Coulter Command must be connected and the power must be ON for the depth sens-
ing gauge wheel to raise when the Preci-
sion Hitch is raised. The depth sensing
gauge wheel should raise with the transport
lift circuit with Coulter Command in either
the AUTO or MANUAL mode is long as the
power is ON.
The lift switch has become disconnected or
the lift switch cam on the rockshaft is not
properly adjusted.
Adjust the lift switch cam. See "Lift Switch"
under Section 2 "Operating Instructions"
on Page 16.Check cable connections on lift
switch leads.
Section 3 Troubleshooting