Axi STS 6004 Installation and operation manual

5400 Division Dr. | Fort Myers, FL 33905
239 690-9589 | Toll Free 877-425-4239 | FAX [phone]
www.AXI-International.com
STS
STS 6004 | 7004 Instruction,
Operating, & Maintenance
Manual
ENCLOSED FUEL MAINTENANCE SYSTEM
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Table of Contents
Table of Contents ................................................................................................................................................................ 2!
General Overview ................................................................................................................................................................ 4!
STS 6004 | 7004 Specifications ......................................................................................................................................... 4!
System Components ........................................................................................................................................................... 5!
Control and Safety Devices................................................................................................................................................ 5!
Pump/Motor........................................................................................................................................................................ 5!
Primary Filter/Water Separator .......................................................................................................................................... 5!
Fuel Conditioner................................................................................................................................................................. 5!
Fine Filter ........................................................................................................................................................................... 5!
Plumbing ............................................................................................................................................................................ 5!
Multi-Tank Assembly (2 Tank) – If Applicable.................................................................................................................... 5!
Auto Water Drain (AWD) Assembly – If Applicable............................................................................................................ 6!
Manual Additive Injection – If Applicable............................................................................................................................ 6!
Auto Additive Injection Assembly – If Applicable ............................................................................................................... 6!
System Operation ................................................................................................................................................................ 7!
Pump Operation ................................................................................................................................................................. 7!
Alarms ................................................................................................................................................................................ 7!
Multi-Tank – If Applicable................................................................................................................................................... 8!
Auto Water Drain (AWD) – If Applicable ............................................................................................................................ 8!
Manual Additive Injection – If Applicable............................................................................................................................ 8!
Auto Additive Injection – If Applicable ................................................................................................................................ 9!
Primary Inspection ............................................................................................................................................................ 10!
Checklist........................................................................................................................................................................... 10!
Installation.......................................................................................................................................................................... 11!
Mounting .......................................................................................................................................................................... 11!
Electrical........................................................................................................................................................................... 11!
Field Connections – If Applicable..................................................................................................................................... 11!
Plumbing .......................................................................................................................................................................... 11!
Typical Plumbing Installation (Schematically) .................................................................................................................. 12!
Important Installation Precautions.................................................................................................................................... 12!
Multi-Tank Installation – If Applicable............................................................................................................................... 12!
Controller............................................................................................................................................................................ 14!
Setting the Current Date and Time (6000 Series Controller) ........................................................................................... 14!
Programming the Timer (6000 Series Controller) ............................................................................................................ 14!
Setting the Current Date and Time (7000 Series Controller) ........................................................................................... 14!
Programming the Timer (7000 Series Controller) ............................................................................................................ 14!
Touchscreen Menu Structure (7000 Series Controller).................................................................................................... 15!
Modbus TCP/IP Communication (7000 Series Controller)............................................................................................... 15!
Priming the System ........................................................................................................................................................... 16!
Priming Procedure ........................................................................................................................................................... 16!
Commissioning/Initial Start-Up ........................................................................................................................................ 17!
Gauge Venting ................................................................................................................................................................. 17!
Switch Adjustments .......................................................................................................................................................... 17!
Internal Pressure Relief Adjustment................................................................................................................................. 17!
Initial Test Procedures ..................................................................................................................................................... 18!
Maintenance ....................................................................................................................................................................... 19!
Preventative Maintenance................................................................................................................................................ 19!
Servicing the Primary Filter/Water Separator................................................................................................................... 19!
Servicing the Fine Filter ................................................................................................................................................... 20!
Replacement Filter Chart ................................................................................................................................................. 20!
Auto Water Drain (AWD) – If Applicable .......................................................................................................................... 20!

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Troubleshooting ................................................................................................................................................................ 22!
Symptom Troubleshooting Guide..................................................................................................................................... 22!
AXI International Limited Warranty.................................................................................................................................. 23!
Warranty Claim Procedure ............................................................................................................................................... 24!
Technical Assistance and Ordering................................................................................................................................. 25!
Accessories and Additional Configuration Parameters .................................................................................................... 25!
Replacement Filter Elements ........................................................................................................................................... 25!
System Identification ........................................................................................................................................................ 25!

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General Overview
STS 6004 | 7004 Specifications
Nominal Flow Rate……………………………………………..
4 GPM/240 GPH (15 LPM/984.2 LPH)
1,920 gallons (7,268 liters) per 8-hour shift
5,760 gallons (21,804 liters) per 24-hour shift
Primary Filter……………………………………………………
10 or 30μParticulate or 60μStainless Steel
Screen with Centrifugal Water Separator
Secondary Filter………………………………………………..
1, 3, 10, or 25μFine Filter or 3, 10μWater Block
Fuel Conditioner………………………………………………..
LG-X 1500 Inline Magnetic Conditioner
Plumbing………………………………………………………...
Black Iron
Inlet Port…………………………………………………………
3/4” NPT
Outlet Port…….…………………………………………………
3/4” NPT
System Enclosure……………………………………………..
NEMA 4 Rated Powder Coated or NEMA 4X Rated Stainless
Steel
Operating Temperature (6000 Series)……………………….
41 - 104°F (5 - 40°C)
Operating Temperature (7000 Series)……………………….
41 - 122°F (5 - 50°C)
Electrical………………………………………………………..
120V/60Hz/15A/1Ph or 230V/50Hz/15A/1Ph*
Pump……………………………………………………………
1/3 HP Spur Gear Pump
Suction Capability (Primed)…………………………………..
15ft. vertical lift or 100ft. horizontal run (lines >1”, primed)
Timer…………………………………………………………....
Incorporated PLC-based timer
Maximum Fluid Viscosity……………………………………..
5 cSt
Outline Dimensions………………………………..…………..
≈36” x 36” x 12” (91 x 91 x 31 cm) (H x W x D)
System Weight…………………………………………………
≈290 lbs (131.5 kg)
*Note: It is the user’s responsibility to ensure safe operating conditions for the system to be ran.
*At 50 Hz., nominal flow rate decreases from 4 GPM/240 GPH to 3.2 GPM/192 GPH.
!WARNING! This system is not meant for use with gasoline or any other flammable liquids having a flash point
less than 100°F (37.8° C). Use with gasoline or any flammable liquids at a temperature exceeding their flash point
presents an immediate explosion and fire hazard.

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System Components
Control and Safety Devices
• System Controller
o Incorporated PLC-based Timer
o Memory retention during power outages
o Alarm Indicator Light(s)
o Control Circuit Breakers (CB1, CB2)
o Pump Control Selector Switch {Hand (Manual) / Off / Auto}
o Alarm Reset Push Button
o Pump Running Indicator Light
o System Power Indicator Light
o Emergency Stop (E-Stop) Push Button
o 6000 Series Controller:
§ Smart Filtration PLC with LCD Display
o 7000 Series Controller:
§ HMI Touchscreen Control
• Water Detection Alarm Module
• Vacuum & Pressure Switches
• Flow Switch
• Leak Detection Float Switch
• Inlet and Outlet Isolation Ball Valves
Pump/Motor
• 1/3 HP Gear Pump
Primary Filter/Water Separator
• Fuel Filter
o Standard-issue back-flushable 30-micron hydrophobic filter cartridge (other filter elements available)
• Water Separator
• One Pair of Water Detection Sensor Probes
• Drain Valve
Fuel Conditioner
• Inline Magnetic Fuel Conditioner
Fine Filter
• Standard-issue 3μwater block cartridge (other filter elements available)
Plumbing
• Black Iron
Multi-Tank Assembly (2 Tank) – If Applicable
• External Bidirectional L-Port Ball Valves
o Enables system to service up to 2 tanks
• Tank Fuel Level Float Switches (Customer provided)

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Auto Water Drain (AWD) Assembly – If Applicable
• Accessory Pump
• Additional Water Detection Alarm Module
• Additional Pair of Water Detection Sensor Probes
• Solenoid Drain Valve
• Basket Strainer
• Water Collection Drum
o High Water Level Float Switch
Manual Additive Injection – If Applicable
• System Ball Valve
• Additive Injection Port
• Injection Port Ball Valve
Auto Additive Injection Assembly – If Applicable
• Accessory Pump
• Flexible Suction/Return Lines
• Additive Injection Flow Sensor
• Solenoid Valve
• Additive Container
• Float Switch/Container Port Assembly

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System Operation
Apply control power to unit. Place control breakers (CB1, CB2) for the System Controller in the “ON” position.
Pump Operation
Automatic Mode:
Switch the system to “Auto” mode via the Selector Switch on the system enclosure. During the time intervals set up by the
user, the pump will start and run until the scheduled runtime has ended. See the Controller section for setting scheduled
run times.
Manual Mode:
Switch the system to “Manual” mode via the Selector Switch on the system enclosure. The pump motor will run until the
system is switched off, into “Auto” mode, or an alarm has been tripped.
Alarms
Alarms featured on the system include:
• Leak Detection (system shutdown, alarm indication)
o Activated when the Float Switch in the system’s drip tray detects a raised liquid level. The system will go
into an alarm state and the pump will not be allowed to run until the alarm is addressed and cleared.
Note: Disposal of fuel and associated waste should be done in accordance with Federal, State and Local regulations.
• Low/No Flow (system shutdown, alarm indication)
o Activated when the Flow Switch on the pressure side of the pump detects a flow rate not adequate for the
pump. Once the alarm debounce timer is expired, the system will go into an alarm state and the pump will
not be allowed to run until the alarm is addressed and cleared.
• High Vacuum (system shutdown, alarm indication)
o Activated when the Vacuum Switch, placed on the suction side of the pump set, detects a reading above
the factory set point. The system will go into an alarm state and the pump will not be allowed to run until
the alarm is addressed and reset.
• High Pressure (system shutdown, alarm indication)
o Activated when a Pressure Switch, placed on the pressure side of the pump set, detects a reading above
the factory set point. The system will go into an alarm state and the pump will not be allowed to run until
the alarm is addressed and reset.
• High Water (system shutdown, alarm indication)
o Activated when water level trips the Water Detection Alarm Module via the Water Detection Sensor
Probes located on the mechanical water separator.
• Pump Overload (system shutdown, alarm indication) – If Applicable
o Activated when the amperage draw from the pump-motor assembly exceeds the factory set point
(determined by the pump’s FLA) on the pump overload relay module.
• Auto Water Drain Float Switch (halts auto water drain functionality, alarm indication) – If Applicable
o Activated when the float switch on the Auto Water Drain’s Water Collection Drum is triggered due to a
high water level.
• Tank Overflow (system shutdown, alarm indication) – If Applicable
o Activated when one of the customer provided tank fuel level float switches is triggered due to a high fuel
level in one of the connected tanks of a multi-tank configuration.
Note: If the Pump Overload Alarm triggers, please contact AXI International.
Once triggered alarms are addressed, each alarm can be reset via the Alarm Reset button on the enclosure door panel.

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Note: For information on factory set points or timer delays please refer to the “Accessories and Additional Configuration
Parameters” subsection in the “Technical Assistance and Ordering” section.
Multi-Tank – If Applicable
1. From the Main Menu screen select “CONFIG”
2. Enter password (9999)
3. Enter the correct number of connected tanks in the box under “Number of Tanks”.
4. To see actual valve positions, select “VALVES”
a. Press the “Open” and “Close” buttons to manually test the valves. If the “Open” or “Closed” rectangular
box is GREEN, that status is active. The opposite is true if said background is RED.
5. Return to Main Menu screen
6. To control Pump in Manual Mode, turn the selector switch on the enclosure door to the “MANUAL” position
7. Select “MANUAL CONTROL” from the Main Menu screen
8. Select the desired tank for manual operation
9. Pump will run when valves have reached correct positions
10. To stop pump operation, select “Cancel Manual” or turn the selector switch on the enclosure door to the “OFF”
position
11. For automatic fuel cleaning, turn the selector switch on the enclosure door to the “AUTO” position
12. Select “AUTO TIMER CONFIG” from the Main Menu screen
13. Program the timer start and stop times for each tank.
a. Use the “Next” and “Prev” buttons in the bottom corners of the screen to navigate between timer screens
for the tanks
Note: Please ensure the start and stop times for any of the tanks do not overlap or an error message will be displayed.
!WARNING! Do not start-up or operate system without high fuel level alarms from both tanks tied into the control
panel. Frequently test overflow alarms for proper functionality and pump shutdown.
Auto Water Drain (AWD) – If Applicable
1. When the Water Separator’s High-Water Sensor is triggered, the system will shutdown
2. The system will remain shut down for 60 seconds, allowing water to be completely separated from the fuel
3. After 60 seconds, the Auto Water Drain Solenoid Drain Valve opens and the Auto Water Drain Accessory Pump
turns on, draining the Water Separator bowl
4. Once the water level has dropped below the Water Separator’s Low-Water Sensor, the system automatically
turns back on and resumes normal operation
Manual Additive Injection – If Applicable
Note: Manual Additive Injection operation may vary depending on the vertical and horizontal distance between the
additive holding container and fuel polishing system.
1. With the system running, place flexible hose between the Additive Injection Port and Additive Container
2. Ensure sufficient additive is present in the container and that the flexible hose reaches the bottom
3. Open the Injection Port Ball Valve to begin injecting additive
4. To start or increase flow of additive into the system, slowly close the System Ball Valve to create a higher vacuum
as indicated on the vacuum gauge
5. Monitor the system’s vacuum gauge to avoid creating a vacuum higher than the system’s set point
Note: If a high vacuum alarm is triggered, return the System’s Ball Valve to the fully open position and reset the alarm by
pushing the Alarm Reset button on the enclosure door panel
6. Monitor the additive level in the holding container to gauge proper dosing

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7. After injecting the desired amount of additive, close the Injection Port Ball Valve and return the System Ball Valve
to the fully open position
Auto Additive Injection – If Applicable
1. To start Auto Additive Injection, navigate from the Main Menu to the Additive Injection screen on the HMI.
2. On the screen there are two fields to input information, Gallons to Treat and Treatment Ratio.
3. There are two other non-editable fields that show the last treatment date and also the amount of additive that was
added from the last treatment.
4. Enter the gallons of fuel to treat.
5. Then enter the treatment ratio (For example: 5 Gallon Jug of AFC treats 25,000 gallons of fuel, so enter 1:5000)
6. Once this information is entered, press the START button to begin the injection process.
7. There is a progress bar that will display the total amount of additive to be added (full red bar), and as the additive
is injected the red bar will decrease.
8. Once the bar is depleted, the process will stop.
9. If at any point the process needs to be manually stopped, press STOP on the screen.
10. After the injection is completed, the data is stored in the log, which can be accessed by pressing LOG on the
Additive Injection screen.
11. When the additive level reaches low, a “LOW ADDITIVE WARNING” will be displayed.
12. In order to run the process again, the additive must be refilled and the alarm reset by clearing all alarms.

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Primary Inspection
Upon arrival, the system and accessories must be visually inspected before installation. Improper handling during
shipping may cause physical or electrical problems. Immediately report or note any damages to the shipper.
Checklist
 If the packing crate shows signs of damage inspect the system for damage.
 Check the entire system for damage that could indicate internal mechanical or electrical problems.
 Check pump/motor hardware and all plumbing connections for tightness.
 Check all electrical terminals and connections for tightness.

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Installation
Note: It is recommended that only qualified, experienced personnel, familiar with this type of equipment, who have read
and understood all the instructions in this manual should install, operate, and maintain the system.
Mounting
The unit should be permanently wall mounted on a hard, level surface. Use provided mounting holes located on the
enclosure for proper fastening (Refer to mechanical drawing(s) for Mounting Hole Diameter). Ensure the system is level
and secure, enabling water to be more accurately sensed in the primary filter’s sump. Be sure to secure the system in a
location that allows all piping and electrical wiring to be safely routed to the system. This unit is designed for well-
ventilated outdoor and indoor use within the specified temperature range and should be located as close to the tank as
possible.
Electrical
!WARNING!: To avoid the risk of electric shock, make sure that the power supply to the system is disconnected
and ensure that the system is at zero volts, before working on any of the system’s electrical parts.
Make sure that the system’s power requirements and rated voltage/frequency match your electrical system (see wiring
diagram). The system may only be connected to properly grounded power sources for operator safety. Connect all
components to the ground studs provided as shown on the provided drawings. After the initial wiring of the system, check
operation to ensure that the motor is running in the correct direction. If the motor is running in the wrong direction, contact
AXI International immediately.
!WARNING!: The whole system (enclosure, plumbing, motor, electric sub panel) must be properly grounded for
operator safety.
Depending on length of run, use wiring according to specification in wiring diagram and connect system to a separate UL
listed breaker (not included) appropriate for branch circuit protection.
Note: Wiring and electrical installation must be in accordance with all applicable federal, state, and local rules, laws,
standards, and regulations.
Field Connections – If Applicable
Remote Monitoring – Dry Contacts:
The System Controller provides two Normally Open (N.O.) dry contacts for remote alarm monitoring. Please see wiring
diagram for contact rating, connection, and location.
1. “Summary Alarm” – dry alarm contact for high vacuum, high pressure, no flow, or water detection
2. “Leak Detection” – dry alarm contact for leak detection
Remote Shutdown – Interlocks:
The customer can provide interlocks connected to the System Controller in order to establish external shutdown
capabilities of the system’s pump.
Note: The 24 V DC provided by the power supply in the electrical box of the system must be used for remote shutdown.
Plumbing
Note: Please ensure to check all of the plumbing (joints, unions, miscellaneous fittings) for tightness prior to completion.

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Use proper quality approved fuel line materials with similar inner diameter (ID) to the inlet/outlet of the system. For
extended suction side plumbing runs, it is recommended to install oversized pipe, (1/4” to 1/2” increased ID) (Ref.: Page 4
– Suction Capability).
Note: Flexible plumbing is strongly recommended for system inlet and outlet connections to external plumbing in order to
avoid issues with thermal expansion, prevent putting any stress on the internal fittings of the system, and enable ease of
maintenance/installation.
The pick-up tube/line(s) should originate from the lowest point of the tank to ensure all water is removed. Also, it should
be connected directly to the system’s inlet port (located on the left-hand side of the system) and be kept as short as
possible. It is recommended that an oversized, low restriction foot valve be installed to keep the system primed, especially
if the inlet port of the system is located above the lowest possible level of fuel in the tank. Additionally, a priming tee
should be installed at the highest point of the suction line to enable priming of the pipelines and system.
The return line(s) should be plumbed to the system’s outlet port (located on the right-hand side of the system) and enter
the tank as far as possible away from the pick-up tube, close to the tank bottom.
Multiple suction and/or return lines may be connected to a manifold outside the system.
Note: Anti-Siphon or other external plumbing devices may be required by state and/or local regulations & code.
Cumulatively, the system capabilities are 15 FT. (4.57 m) suction (vertical lift) or 100 FT. (30.48 m) horizontal run, when
connected to the minimum recommended piping size (Ref.: Page 4 – Inlet/Outlet Port), or more, with no additional flow
restrictions. That includes valves, 90-degree connectors, or other plumbing accessories. For continuous optimal
performance, make sure suction and discharge lines are free of contamination, nothing is blocking the flow of fuel, and the
suction line always stays primed.
Note: Plumbing installation must be in accordance with all applicable federal, state, and local rules, laws, standards, and
regulations.
Note: Additionally, if the system must share a fuel oil supply (FOS) line with a generator, we recommend check valves be
installed after the split in the line, before the landing/entrance into the generator tank and the fuel polishing system. Also, it
is highly recommended that the “External Shut Down” contacts on the PLC are utilized as well in this scenario.
Typical Plumbing Installation (Schematically)
See provided P&ID drawing(s).
Important Installation Precautions
The suction line of the system should be independent and separate from the suction line of the engine. If that is not
possible, appropriate valves must be installed to completely separate the system from the engine’s fuel system to prevent
any possible interference with safe engine operation (please see note above).
Also, it is highly recommended to plumb the discharge line independent and separate of the engine’s fuel return line back
to the tank. If the return line from the engine and the discharge of the system must be combined in any way, adequate
valves should be installed to prevent any possible interference with safe engine operation.
Multi-Tank Installation – If Applicable
Please connect each tank’s dedicated supply and return lines according to the provided drawings. Use approved flexible
lines to allow to avoid issues with thermal expansion, prevent putting stress on plumbing connections, and enable ease of
maintenance/installation.

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The provided external High Tank Fuel Level Alarm Inputs (see provided electrical drawings) must be wired to the Normally
Closed High Level Alarm Contacts on both tanks to avoid overfilling of either tank and potential spills. This is a very
important safety feature that will shut the STS pump down in case a tank reaches an unsafe high level of fuel.

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Controller
Setting the Current Date and Time (6000 Series Controller)
• Please make sure the selector switch is set to “OFF” and push the Alarm Reset button on the enclosure door
panel.
• When power is first applied to the system, the display of the PLC will show (blinking) the date and time.
• Hit the “ESC” button.
• Select ‘Stop’ and press “OK”.
• Select ‘Yes’ (use down arrow key) and press “OK”.
• Select ‘Setup’ (use down arrow key) and press “OK”.
• Select ‘Clock’ and press “OK”.
• Select ‘Set Clock’ and press “OK” (must be in military format).
• Using the arrow keys, set the current day of the week, time and date as indicated in the display and press “OK”.
Use the up and down arrow keys to change values, and use the left and right arrow keys to change between
week, day, time, and date.
• When finished entering press “OK” to confirm.
• Press “ESC” until the base menu is displayed.
• Select ‘Start’ and press “OK” – correct time and date should be displayed (when prompted, select “YES” to
proceed).
Programming the Timer (6000 Series Controller)
1. Hit the “ESC” button from the time and date display. If they are not shown, hit the down arrow button until they are
displayed.
2. Select ‘Program’ and press “OK”.
3. Select ‘Set Param’ (use arrow keys) and press “OK”.
4. Use the arrow key to select the ‘Timer’ and Press “OK”.
5. Use the arrow keys to select the desired field and press “OK” to edit.
6. Use the left and right arrow keys to select the day/days of the week the system should automatically turn on, and
the up or down arrow key to activate the selected day.
7. Use the arrow keys in same manner to program the ‘On’ time for when the system will switch on (on the selected
day/days).
8. Use the arrow keys in same manner to program the ‘Off’ time – when the system will switch off.
9. Press “OK” to confirm the entry when finished setting all desired parameters.
10. If required, you can set up to 3 Timers by using the up and down arrow keys.
11. Press “ESC” until the time and date screen is displayed.
Setting the Current Date and Time (7000 Series Controller)
1. Please make sure the pump is set to “OFF”.
2. On the home screen, long-press (for a few seconds) to the right of the AXI logo until a new screen appears.
3. Select ‘Enter Info Mode’.
4. Once prompted, enter ‘1111’ for the password.
5. Select ‘Time and Date’.
6. Select and set the current time and date in military format.
7. Once finished, continually press ‘ESC’ until you are returned to the home screen. The updated information should
be shown in the header of the touch screen pages.
Programming the Timer (7000 Series Controller)
1. From the home screen, select ‘Timers’.
2. Once on the ‘Timers’ screen, you can set up to 3 run timers for each day of the week.

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3. To set up a runtime simply enter a ‘Start’ and ‘Stop Time’ (using military format) in one of three timer boxes for the
desired weekday.
4. To toggle between weekdays, simply press the available buttons on the left or right of the screen labeled with the
abbreviation for the previous or next day in the week (e.g. “MON”, “WED”).
Touchscreen Menu Structure (7000 Series Controller)
Modbus TCP/IP Communication (7000 Series Controller)
Setting up the IP Address:
1. From the Main Menu, press the “CONFIG” button.
2. Input “9999” and press the enter key (“↵”).
3. Push “IP Config” and continue onto the next page.
4. Enter the desired values for the PLC IP Address, PLC IP Mask, PLC IP Gateway, PLC Remote IP,
and Network ID.
5. Power cycle the touch screen HMI/PLC.
Note: When communicating via Modbus TCP/IP (Port 3 – Ethernet Cable Slot), the PLC Remote IP and Network ID do not
need to be utilized for the proper functionality.
Home
Screen
Alarm
History Alarms
Groups
w/Pending
Alarms
Alarms In
Group
Alarm Detail
Auto Timer
Config. Manual Control Config.
Password
"9999"
Config. Menu
Clear
Totalizer Clear Alarm History IP Setup Valves

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Priming the System
The pump supplied with the system is NOT automatically self-priming and must not be run dry.
!WARNING! If the pump is allowed to run without fuel, pump damage can occur.
Priming Procedure
The head of the pump on the system is shipped from the factory filled with No. 2 Diesel Fuel Oil in it to facilitate initial
lubrication. This will not eliminate the necessity to prime completely the system. An externally installed priming tee (not
provided) should be utilized to prime the system. Additionally, the lid of the primary filter can be removed, and the filter
housing and suction plumbing can be filled through that method, as well. The primary filter along with the suction line(s)
must be completely filled with fuel (no trapped air) prior to initial system start-up.
The system is equipped with a vacuum gauge on the input side of the pump. The gauge should read no more than 15” HG
vacuum maximum under normal conditions. Vacuum gauge readings reaching 16” HG indicate excessive debris in the
primary filter/water separator. Also, it could be derived from above average flow restriction or too high suction height. This
will likely result in pump shutdown and activate the high vacuum alarm.
Note: 16” HG vacuum = clogged primary filter or suction line flow restriction/excessive lift.
The system’s pressure gauge should show 22 PSI maximum pressure under normal conditions (.433 PSI = 1’ vertical
head pressure). Pressure gauge readings in excess of 22 PSI pressure indicate the need for filter replacement, or fuel line
restrictions and/or friction.
System pressure over 22 PSI indicates a high-pressure alarm and will automatically shut down the pump.
The pump pressure relief valve has a 48-50 PSI set point. System pressure in excess of 48-50 PSI will cause the
pressure relief valve to open and vent fuel back to the fuel transfer pump inlet side.

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Commissioning/Initial Start-Up
Gauge Venting
After shipment, gauge pointers may not rest at zero due to internal case pressure build-up, which is caused by
temperature and/or pressure variations. As a result, their accuracies may be significantly reduced. To restore the gauges
to operating condition, move the yellow lever of the fill plug to the open position or remove the black rubber piece from top
of gauge and leave it open to vent.
Switch Adjustments
Note: Please contact AXI International before adjusting either the vacuum or the pressure switch to avoid voiding the
system’s warranty.
Vacuum and Pressure Switches
When the value exceeds the set point of the switches’ rating, the switch will change state. Ensure you are working with a
normally closed position (leads on opposite sides of the switch – across from one another are connected to the wire
spades). If the set point is incorrect, adjustments can be performed in the field as follows:
1. Remove the two wires connected to the normally closed spades on the top of switch.
2. Pop off the “Rubber Plug” in between the spades on top of the switch.
3. Insert a 5/64” Allen Wrench/Key into the slot.
4. For a vacuum switch, adjust the Wrench/Key ¼- ½turn at a time CCW to increase the vacuum alarm’s set point.
5. For a pressure switch, adjust the Wrench/Key ¼- ½turn at a time CW to increase the pressure alarm’s set point.
6. After adjusting the settings, perform the testing procedure(s) for the switch(es) as outlined in the commissioning
section.
Flow Switch
When the flow rate drops below the predetermined set point on the flow switch (i.e. 10 GPM), the switch will trigger a
signal to shut down the pump. If the set point is incorrect, an adjustment can be performed in the field as follows:
1. Loosen the lock screw on the stem of the flow switch using the provided Hex Allen Key
2. Rotate the setting dial on the flow switch until the desired GPM flow range printed on the stem is reached.
a. If the Orange LED light on the Flow Switch’s M12 Connector is not illuminated, a flow rate lower than its
set point is being detected.
b. Turn the black neck of the Flow Switch CW. Once the point is reached where the Orange LED light turns
on, turn the dial one more full turn CW.
3. Tighten the lock screw to secure the setting dial’s placement
4. After adjustment, ensure to perform the relevant testing procedure outlined below
Note: For information on factory set points or timer delays please refer to the “Accessories and Additional Configuration
Parameters” subsection in the “Technical Assistance and Ordering” section.
Internal Pressure Relief Adjustment
Note: Please consult AXI International before performing any internal pressure relief settings to avoid warranty issues
The pump used on the STS systems come from the factory with a pre-set internal pressure relief bypass. If the pressure
on the discharge of the pump rises past this set point, the internal bypass will open and recirculate the fuel in the head of
the pump to protect the itself and any downstream components. When this happens, the discharge branch of the system
will not see the proper fuel flow, most likely causing the system to fail on a low flow alarm.

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By adjusting this Internal Pressure Relief to a point past the set point on the Pressure Switch, the system will fail on a
High-Pressure condition before the relief begins to open, allowing fuel to flow fully while within the acceptable pressure
range. The desired set point for pump Internal Relief Valve is around 48-50 PSI, which is higher than the pressure switch
setting, and lower than the operational pressure limit on the system fine filter.
Tightening the Bypass Spring:
1. To tighten the spring in the pump head, remove the blue cover nut located on the left side of the pump head
2. Loosen the secondary nut to allow for screw adjustment
3. Using a flathead screwdriver, tighten the screw two full turns (clockwise)
4. Restore the secondary nut and blue cover, tightening them down to their original positions
Initial Test Procedures
With breakers and power turned on, and pump running, check all alarms for proper operation:
• Leak Detection - Manually raise the float switch located at the bottom of the leak-basin. The pump should
immediately turn off and the “Leak Detection” alarm should be indicated on the System Controller. Reset the
alarm by lowering the float switch and pushing or selecting the Alarm Reset button on the enclosure door panel.
• High Vacuum Alarm - Slowly, partially close the inlet ball valve. At 16” HG, the pump should turn off and “PLS
SERVICE PRIM. FILTER…” or “High Vacuum” alarm should be indicated on the System Controller. Open the
inlet ball valve again. Reset the alarm by pushing the Alarm Reset button on the enclosure door panel.
• High Pressure Alarm - Slowly, partially close the outlet ball valve. At 22 PSI, the pump should turn off (after a
delay of about 1 second) and “PLS SERVICE SEC. FILTER…” or “High Pressure” alarm should be indicated on
the System Controller. Open the outlet ball valve again. Reset the alarm by pushing the Alarm Reset button on
the enclosure door panel.
• Water Sensor - Jump the Water Detection Sensor Probes by placing a conductor across the two horizontal
contacts. The pump should turn off after 10 seconds and “High Water Alarm” or “PLS. DRAIN WATER/BOWL…”
should be indicated on the System Controller. Remove the metal and reset the alarm by pushing the Alarm Reset
button on the enclosure door panel.
Note: Systems with the Auto Water Drain (AWD) functionality have two sets of water sensing probes on the primary filter
bowl. Please refer to the AWD section on for additional information.
• No Flow Alarm – Ensure orange light indicator turns on when the system pump is on (moving fluid) and off when
the system is not running. Disconnect the M12 connection on the back of the flow switch. The pump should turn
off and the “No Flow Alarm” or “PLEASE PRIME SYSTEM / CHECK FLOW” should be indicated on the System
Controller up to 15 seconds after disconnection. Use Flow Switch Setting & Adjustment instructions to return the
switch to the proper setting. Reset the alarm by pushing the Alarm Reset button on the enclosure door panel.
• Auto Water Drain Float Switch (If Applicable)- Manually raise the “HIGH” float switch located on the Auto
Water Drain’s Water Collection Drum. An alarm should be indicated on the System Controller. Reset the alarm by
pushing the Alarm Reset button on the enclosure door panel.
• Tank Overflow (If Applicable)– Manually raise the “HIGH” float switch located on each of the connected tanks.
The pump should immediately turn off and the “Tank Overflow” alarm should be indicated on the System
Controller. Reset the alarm by pushing the Alarm Reset button on the enclosure door panel.
Note: If any of the above described alarm test procedures fail or if any alarm trip value deviates, immediately contact AXI
International.

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Maintenance
The system should be visually inspected and tested a minimum of every six (6) months according to the
procedure below during light duty cycles. Monthly inspections are recommended for systems that are being used
in excess of an average of eight (8) hours a day and five (5) days a week.
Preventative Maintenance
Prior to performing the maintenance procedure ensure that:
1. The electrical sub-panel mounted main disconnect switch is operating properly.
2. The user supplied remote circuit breaker is in the “OFF” position.
3. All sources of power are isolated from the unit.
Note: Proceed only after this has been verified and properly tagged.
4. Drain visible water and sediment from the primary filter (see Servicing Primary Filter/Water Separator).
5. Check system and all parts for corrosion and rust.
6. Check mounting hardware – tighten as necessary.
7. Check bolts on the pump/motor hardware for tightness, as pump/motor hardware can loosen after normal
operation for extended durations of time, due to vibration.
8. The hardware uses lock nuts – check all bolts for secure nuts.
9. Check all electrical terminals and connections for tightness.
10. All motors are permanently lubricated and do not require any lubrication.
11. Check all plumbing joints for leaks, tighten fittings and joints as necessary, and remove accumulated fuel in leak-
basin as necessary.
12. Inspect all filter(s) and separator.
Note: All filter elements should be replaced at least every six (6) months.
Servicing the Primary Filter/Water Separator
Clogged primary filter elements restrict the flow of fuel, resulting in the system’s vacuum gauge indicating a pressure drop.
The gauge reads the condition between the Primary Filter and the pump. At a pressure drop of 16” HG, the pump will
automatically shut off and activate an alarm. This signal indicates that it is time to either back flush or change the filter
element.
Servicing and back-flushing Primary Filter:
1. Turn the enclosure door panel selector switch to the “OFF” position – making sure the pump will not turn on.
2. Close the inlet and outlet ball valves.
3. Open the bleed screw at the top of the Primary Filter cover.
4. Place a fuel waste container below the yellow safety drain valve on the bottom of the filter bowl (unless system is
equipped with the Automatic Water Drain option – OPT-AWD).
5. Open the yellow safety drain valve (push & turn counterclockwise).
6. Close after approximately 2 seconds.
7. After approximately 10 seconds, reopen the drain valve, allowing water to settle out of the fuel.
8. Close after visible sediment, particles, and water have been drained from the bowl.
9. If the filter requires changing, remove the filter from the housing by loosening the four bolts that hold the top plate
in place. Remove the spring-loaded cartridge and replace the filter.
10. Prime the filter by following the instructions found in the Priming section of this manual and ensure that the fuel
level is above the primary filter’s outlet port.
11. Replace the lid and ensure to carefully and evenly re-tighten the four bolts of the top plate to avoid damaging it
and to create a good seal.
12. Close bleed screw on the top of the lid.