Cardinal GUARDIAN User manual

The GUARDIAN®
HYDRAULIC FLOOR STAND
TANK/HOPPER ASSEMBLIES
OWNER'S MANUAL
1780-M057-O1 Rev C
203 E. Daugherty, Webb City, MO 64870 USA
11/14
Ph: 417-673-4631  Fax: [phone]
Printed in USA
www.cardinalscale.com
Technical Support: Ph: 866-254-8261  [email protected]

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TABLE OF CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 1
Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 1
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 2
Gauging SST Hydraulic Load Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 5
Gauging H2.5K and H5K Hydraulic Load Cells . . . . . . . . . . . . . . . . . . . . . . . . .
Page 7
Final Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 9
Indicator Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 11
Conformal Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 13
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 13
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 14
SST Hydraulic Load Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 14
H2.5K and H5K Hydraulic Load Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 15
PTG-3K Transducer Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 16
Recommended Sealing Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 17
Parts Identification
H2.5K Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 18
H2.5K Load Cell Stand
(HBC2.5, Mild Steel and HBCS2.5, Stainless Steel) . . . . . . . . . . . . . . . . . . . . . .
Page 20
H5K Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 24
H5K Load Cell Stand
(HBC5, Mild Steel and HBCS5, Stainless Steel) . . . . . . . . . . . . . . . . . . . . . . .
Page 26
SST10 Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 30
SST10 Load Cell Stand
(HBC10, Mild Steel and HBCS10, Stainless Steel) . . . . . . . . . . . . . . . . . . . . . . .
Page 32
SST25 Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 36
SST25 Load Cell Stand
(HBC25, Mild Steel and HBCS25, Stainless Steel) . . . . . . . . . . . . . . . . . . . . . . .
Page 38
SST50 Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 42
SST50 Load Cell Support Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 44
SST75 Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 46
SST75 Load Cell Support Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 48
SST100 Load Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 50
SST100 Load Cell Support Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 52
3 & 4-Cell Totalizer Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 54
Cell Output Calibration Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 58
PRECAUTIONS
Before using this product, read this manual and pay special attention to all
"NOTIFICATION" symbols:
IMPORTANT
ELECTRICAL
WARNING
STATIC
SENSITVE

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INTRODUCTION
The Guardian® System is a unique hydraulic based weighing system that utilizes Stainless Steel
hydraulic load cells as a load receiving element. The load cells are coupled by copper or
stainless steel tubing to a totalizer enclosure. The totalizer enclosure contains a simple manifold
assembly and a Cardinal PTG-3K Pressure Transducer for each load cell. The Pressure
transducers convert the hydraulic pressure generated by the load cell to an analog signal that is
easily trimmed and summed.
The Guardian® has no electronic components at the scale. All components at the scale are
highly resistant to water, moisture, lightning damage, and vibration.
IMPORTANT! This manual must be used in conjunction with certified drawings of the
particular weighing system being installed. In case of conflict, the certified drawings
will govern. We recommend that you read this manual in its entirety before starting the
installation.
SITE PREPARATION
Site preparation is consistent with any other scale installation. Conduit, if required, should be
stubbed up at each load cell stand and run to the location of the totalizer enclosure. Any
deviation from this should be noted since extra tubing may be required. Tubing length may not
exceed 125 feet from the load cell to the totalizer, and no splices are allowed. Consideration
should be given to avoid tight radius bends in the conduit that would make it difficult to pull the
tubes to the totalizer enclosure. The totalizer enclosure should be located in a protected area
close to the scale and the indicator cable run in conduit to the weight indicator if long tube runs
need to be avoided. The totalizer enclosure may be located near the weight indicator if it is
convenient to the scale.

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INSTALLATION
In most installations it is advisable to locate and install the cells before the vessel or weighbridge
is set in place. If the cell stand assemblies are installed with the vessel or weighbridge in place,
extreme care should be taken to ensure that the stability of the vessel or weighbridge is
maintained during installation of the load cell stands.
Figure No. 1 – Load Cell and Stand
Figure No. 2 – 3 & 4-Cell Totalizer

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Be sure to leave a loop of tube at each load cell so that the cell can be moved a bit
if necessary and also to allow a tube to be cut off and a new ferrule set installed if
necessary. NEVER attach the tube to the scale weighbridge as the vibration will
lead to fatigue and failure of the tube to load cell connection.
INSTALLATION, CONT.
Next, mount the totalizer enclosure on a wall as close to the digital weight indicator as possible.
The totalizer enclosure should be mounted with at least 24 inches of clearance below it to allow
room to connect the hydraulic tubes running from the cells to the bulkhead fittings. The 2 inch
conduit from the scale should be stubbed up directly under the left side of the totalizer enclosure
for the easiest installation. The totalizer should be located such that it is exposed to the same
temperatures as the load cells. This ensures the proper operation of the temperature
compensation circuits.
After the cells and the totalizer enclosure have been located, the hydraulic tubes must be cut to
length and installed. Always start with the longest runs first and be aware that the drops from
some of the longer runs may be used for shorter runs.
1. Using a sharp tube cutter, cut about one inch off of the end of each tube.
2. Cut only half way through the tube then gently bend the tube back and forth to finish the cut.
This keeps the inside diameter of the tube from collapsing when the cutter breaks through the
tube wall. Use a jeweler’s file to remove any burrs from the end of the tube.
3. Place the nut and inner and outer ferrule over the tube and then assemble it finger tight onto
the load cell or totalizer fitting.
4. Mark the nut so that you can tell where you began tightening the fitting and tighten ¾ to 1 turn.
5. Swagelok makes a simple gage to check the connection, so that if it will slide in between the
fitting and nut, it needs tightend more.
6. If you must remove a fitting, they recommend you mark the nut and fitting so that when you
reassemble the connection you go back to exactly the same place, and then an additional 1/8
to 1/4 turn.
Figure No. 3 – Swagelok Gap Inspection Gauge

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INSTALLATION, CONT.
Figure No. 4
(3 & 4-Cell Totalizer Enclosure with Suppressor Package)
Connect the load cell tubes to the totalizer enclosure bulkhead fittings. The tubes are normally
installed with the tube for cell #1 being installed toward the front of the enclosure with the odd
cells on the left and even cells on the right. The tube caps should be installed finger tight then
tightened an additional 1/8 to 1/4 of a turn to lock the fitting in place. All of the cell tubes should
be installed at this time.
Suppressor Package
Manifold Fittings
Load Cell Tubes

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IMPORTANT! It should be noted that a load should NEVER be applied to a load cell
unless the circuit for that cell is sealed and the cell has the correct amount of oil in it.
Placing a load on a load cell with no oil, or the incorrect level of oil in it can damage
the pressure diaphragm in the cell.
INSTALLATION, CONT.
Gauging SST Hydraulic Load Cells
Filling and bleeding the system is a very simple procedure. Begin by filling the pressure pump
with oil and attaching it to the inlet port located on the outside, bottom right side of the totalizer
enclosure. This pump is used to push oil through the system for bleeding purposes.
1. Next, remove the plastic gauge port plugs from load cell number one and place a .026 inch
thick shim in each of the three gauge ports.
2. Place a container under the tube at the load cell to catch oil as air is purged from the line.
Figure No. 5
(Load Cell with 0.26 Shim in Gauge Port)
Figure No. 6 – Load Cell Gauge Ports
Gauge Port
Gauge Port
Gauge Port
.026 Shim

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INSTALLATION, CONT.
Gauging SST Hydraulic Load Cells, Cont.
3. Open Manifold valve number one and pump oil through circuit number one until no air
bubbles are seen coming out of the load cell end of the line.
4. Now remove the plug at the load cell inlet fitting and install the tube.
5. Tighten the tube nut finger tight, then an additional 1/8 to 1/4 turn.
6. Next remove the cap from the bleed port on the cell and attach a plastic bleed hose
placing the end in a clean glass container.
7. Now pump 10 to 12 strokes of oil through the cell to ensure the cell has no trapped air
inside it. If air bubbles are still visible coming from the plastic line continue pumping oil
through the system until no further air remains.
8. Next, remove the plastic bleed tube and replace and snug the bleed port cap. After the
cap is installed stroke the pump one more time and close the manifold valve for cell
number one.
9. See if the three gauge shims are tight in the cell. If not open the bleed valve and pump
another stroke of oil into the cell.
10. Continue this procedure until the shims in the cell are snug.
11. At this point tighten the bleed screw in the manifold.
12. Now carefully open the bleed cap and let a few drops of oil out of the load cell until the
shims can be pulled free and tighten the bleed cap.
13. At this point the cell’s gauge gap, at the tube connection “gauge port” (it is not necessary
to gauge the other two ports) should be very close to the .027 +/- .001 gap that is
necessary for operation.
14. Repeat this procedure on all cells in the system until all cells are bled and filled to the
correct level.
15. Double check the gap after the weighbridge or vessel has been placed on the load cells.
16. Replace the gauge port caps on the cells.

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INSTALLATION, CONT.
Gauging H2.5K and H5K Hydraulic Load Cells
The procedure for gauging the H2.5K and H5K load cells used in Guardian scales is significantly
different than gauging the SST series of load cells. Where the SST series use a simple set of
feeler gauges, the H2.5 and H5 load cells use a special gauging pin to gauge the correct amount
of oil in the load cell.
The gauge pin is a simple tool that has corresponding diameters to match the gauge port
dimensions on the specific load cell (the H2.5 and H5 are different).
Figure No. 7 – H2.5K Gauge
1. When we are setting up a scale using the H2.5 or H5 load cells we always want to start with
the cell out of oil and the piston all the way down.
2. Carefully bleed the cell to make sure all air is out of the circuit, and then apply pressure on
the top of the cell to force oil out of the bleed port.
3. Remove the bleed tube and install and tighten the port cap.
4. Next remove the gauge port plug and slide the gauge in the port. It will contact the piston
before it goes all the way in.
Figure No. 8 – Gauge Pin in Port with Piston Down

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INSTALLATION, CONT.
5. Next open the corresponding valve on the manifold, push the gauge into the cell against the
piston and apply a bit of pressure. Very slowly add oil to the cell until the gauge snaps into
the gauge slot in the piston. This locates the piston at the correct height.
Figure No. 9
(Load Cell with correct amount of oil and Piston at correct height)
6. Tighten the manifold valve; make sure the gauge will slide in out of the gauge slot with Dead
Load applied to the cell. Replace the gauge plug.
It is very important that you do not over fill the load cell. Small capacity
Cardinal cells contain a diaphragm that can be damaged by over pressure. If
the amount of oil in the cell is not known ALWAYS bleed all oil out of the cell to
lower the piston and add fluid to bring it up to the correct height.
7. After all cells have been bled and filled, remove the pump from the totalizer and tighten all
valves and system fittings.

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FINAL ASSEMBLY
IMPORTANT INSTALLATION NOTES!
1. THE PURCHASERS OF FLOOR STAND TANK/HOPPER SCALE COMPONENTS
ARE ADVISED TO INSTALL SAFETY STAY RODS. CARDINAL SCALE
MANUFACTURING CO. (CSMC) WILL NOT BE RESPONSIBLE FOR THE
STABILITY OF THE TANK.
2. IT IS RECOMMENDED THAT ALL PIPE CONNECTIONS TO THE TANK BE
FLEXIBLE. (CONSULT FACTORY FOR PIPING FLEXIBILITY.)
3. PROVIDE FIRM, LEVEL STABLE AND SMOOTH SURFACE FOR LOAD CELL
MOUNTING. LOAD CELLS MAY BE ROTATED TO SUIT CUSTOMER’S SPECIFIC
INSTALLATION. SHIM AS REQUIRED.
4. FOR APPLICATIONS WHICH REQUIRE PERIODIC DEAD WEIGHT CALIBRATIONS,
WEIGH LIFTING LUGS (NOT PROVIDED BY CSMC) ARE TO BE PROVIDED ON
TANK.
5. CONSULT FACTORY FOR SPECIAL APPLICATIONS AND/OR INSTALLATIONS.
6. FOR SST10 INSTALLATIONS, REFERENCE DRAWING 1771-B280-GS,
HYDRAULIC LOAD CELL STAND DIMENSIONAL OUTLINE DRAWING.
FOR SST25 INSTALLATIONS, REFERENCE DRAWING 1771-B282-GS,
HYDRAULIC LOAD CELL STAND DIMENSIONAL OUTLINE DRAWING.
FOR SST50 INSTALLATIONS, REFERENCE DRAWING 1771-B230-0A, HYDRAULIC
LOAD CELL STAND DIMENSIONAL OUTLINE DRAWING.
FOR SST75 INSTALLATIONS, REFERENCE DRAWING 1771-B229-0A, HYDRAULIC
LOAD CELL STAND DIMENSIONAL OUTLINE DRAWING.
FOR SST100 INSTALLATIONS, REFERENCE DRAWING 1771-C320-0A,
HYDRAULIC LOAD CELL STAND DIMENSIONAL OUTLINE DRAWING.
7. THE PURCHASER OF A FLOOR STAND TANK SCALE IS ADVISED TO INSTALL
SAFETY PIERS OR OTHER DEVICES BENEATH THE WEIGHBRIDGE/SCALE, TO
LIMIT MOVEMENT OF SCALE ASSEMBLY SHOULD ONE OR MORE SUPPORT
MEMBERS FAIL.
8. CHECKS (NOT FURNISHED BY CSMC) ARE REQUIRED NEAR TOP OF TANKS
SUBJECTED TO LATERAL (OVERTURNING) FORCES. CSMC WILL NOT BE
RESPONSIBLE FOR THE STABILITY OF THE TANK.

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FINAL ASSEMBLY, CONT.
Figure No. 10 – Typical Mounting Configuration for 4-Mount Circular
Tank Leg
Provide Bracing
Between Legs
for Stiffness

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INDICATOR INSTALLATION
1. Install the digital indicator.
2. The indicator cable is terminated at the Surge Suppression box located in the front door of
the Totalizer enclosure. Make sure the surge suppression box is grounded back to the
indicator and the AC power ground. Failure to provide a good ground will make the surge
suppression inoperative. See Figure No. 11.
Figure No. 11 – Ground Lug Location
The Ground wire must be attached to the ground lug on the Suppressor
Package. It should be run with the indicator cable and terminated to the ground
lug on the weight indicator.
3. Power up the indicator, remove the signal lines from the summing card and read the signal
from each transducer. Any transducer/cell pair that has a low output should be inspected to
make sure it is taking load. If necessary place a small shim under the lower frame cell pad.
DO NOT ADD OIL TO THE CELL!!
Ground Lug

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INDICATOR INSTALLATION, CONT.
4. Span the indicator and corner seal the scale using the trim pots in the summing box like any
other scale. Refer to Figure No. 12.
Figure No. 12 – J-Box Trim Assy.
5. If necessary the Guardian Linearization software in the indicator can be used to tweak out
any small errors.

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CONFORMAL COATING
After installation and testing have been completed, the last step is to conformally coat the
summing card using Cardinal Part number 6560-0017, CONFORMAL COATING, SILICONE.
Apply the coating by spraying from top to bottom, holding the can 6 to 8 inches from the summing
card. It is best to apply 2 to 3 coats changing the angle a little each time for the best coverage.
The coating dries to the touch in 1 hour and cures in approximately 72 hours. The wiring should
not be disturbed until after the curing time.
MAINTENANCE
Like any other scale the Guardian system needs routine maintenance to keep it working to its
potential. Since there are no electronic components in the scale itself this is simplified on the
Guardian.
1. After initial installation it is recommended that gauge gaps on the load cells be checked
after the scale has been in use one week, again after one month of use and then every
six months. If there is a very small leak in one of the cell circuits it may not be apparent
during initial setup and calibration of the scale.
2. The scale should be inspected for dirt and debris under the weighbridge or vessel and
cleaned every three (3) months or more often depending on the application.

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TROUBLESHOOTING
SST Hydraulic Load Cells
If you are having a problem with a cell loosing fluid (it will always be weighing light) remove the
gauge port and see if the gauge will go into the cell. If not, we need to determine for sure that the
cell has lost oil.
1. On the initial inspection, make sure the .028 feeler gauge will not enter the cell gauge gap.
It is very important that if on inspection you find the gap at .035 inch that you find the
source of the leak and eliminate it.
2. There is a rubber wear pad inside the cell that may compress slightly with use. A gap that
has increased to .029 may just be because of the rubber pad compressing. Any increase
in the gap above .029 means that fluid has left that circuit either at a cell, tube, or fitting, or
inside the totalizer enclosure in a hose or manifold.
3. If the cell has lost fluid, you must find the source of the leak and fix it. Simply pumping
more oil in the cell may get it going again but it will soon fail.
4. Clean all fittings and the area around the cell (spray brake or carb cleaner works well)
then wrap the fittings with absorbent tissue and apply a heavy load to the cell that appears
to be leaking.
5. After a period of time remove the tissue and inspect it for signs of oil. If no external leaks
can be found the cell should be considered suspect.
6. If you are unsure of the level of oil in the cell ALWAYS open the bleed port and let oil out of
the cell and add it back until the .028 feeler gauge will not enter the cell gauge gap.
7. After the problem has been found and fixed, remove all load from that cell and bleed and
gap it to .027 inch. Then apply load and verify the gauge gap.

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TROUBLESHOOTING, CONT.
H2.5K and H5K Hydraulic Load Cells
If you are having a problem with a cell loosing fluid (it will always be weighing light) remove the
gauge port and see if the gauge pin will go into the cell. If not, we need to determine for sure that
the cell has lost oil.
1. Take a stiff piece of wire (.045 welding wire works well) and use it to feel the position of the
slot in the load cell. If the cell is low or out of fluid you can feel the top edge of the slot with
the wire, and above it the piston.
Figure No. 13 – Probing cell gauge port to determine piston position.
2. If the cell has lost fluid, you must find the source of the leak and fix it. Simply pumping
more oil in the cell may get it going again but it will soon fail.
3. Clean all fittings and the area around the cell (spray brake or carb cleaner works well)
then wrap the fittings with absorbent tissue and apply a heavy load to the cell that appears
to be leaking.
4. After a period of time remove the tissue and inspect it for signs of oil. If no external leaks
can be found the cell should be considered suspect.
5. If you are unsure of the level of oil in the cell ALWAYS open the bleed port and let oil out of
the cell and add it back until the gauge snaps in the groove in the piston.

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TROUBLESHOOTING, CONT.
PTG-3K Transducer
The Cardinal PTG-3K pressure transducer is a simple device to convert hydraulic pressure into a
voltage output that can be easily summed and trimmed. It can be checked much the same as a
standard strain gauge based load cell.
Figure No. 14 – PTG-3K Pressure Transducer
The PTG-3K is rated at 1mV/V. Because of this you will see exactly half of the output from the
transducer that you would normally see out of a 2mV/V load cell. The Transducer uses a
modified Wheatstone bridge circuit and uses Balco resistors for span temperature compensation
as well as copper alloy for zero temperature compensation.
To troubleshoot the PTG-3K you will first measure the resistance between the red and white
signal leads. This value should be from 340 ohms to 360 ohms. Resistance between the black
and green excitation leads will be from 402 ohms to 422 ohms.
Resistance from the circuit wires to the transducer body should be 5K Megohms (5 billion ohms)
Normally a standard VOM meter is not capable of measuring this resistance. A Megohmmeter
(also called an Insulation Resistance Tester) is required.
Since the PTG-3K will always have some amount of pressure on the gauged surfaces, it is
impossible to check the absolute zero balance condition of the transducer without removing the
transducer from the hydraulic circuit. This is something you normally will not want to do. When
the scale is first set up you should record the output of the transducer with the deck jacked up off
of the load cell. This value should be recorded and left inside the transducer cabinet so at a later
date you can compare the no-load output from the transducer to see if there has been a
significant shift in zero. A change of .2mV from the initial reading may indicate a change in the
sensor output.
If a sensor must be changed in the scale, first jack up the weighbridge at the corresponding load
cell to eliminate pressure from that circuit. Apply 2 wraps of Teflon tape to the new transducer
threads and force them all the way into the bottom of the threads. Remove the transducer to be
replaced, clean the manifold threads and check for loose Teflon in the manifold and install the
new PTG-3K. The sensor should be very tight in the manifold to avoid leaks. Bleed the circuit
and set the gauge gap in the cell and the scale should be ready to be calibrated.