HPCF-SFI — Controls & Operation – South-Tek Systems

Applies to: HPCF-SFI — catalog numbers HPCF-SFI-0004, HPCF-SFI-0110, and HPCF-SFI-0130

Does NOT apply to: HPCF Series — see HPCF Series Controls & Operation

The HPCF-SFI is controlled through a proprietary PLC with a full-color touchscreen. This article describes every screen and control function available to operators and technicians. Controls for supporting equipment — including the integrated air compressor and refrigerant dryer — are managed through the PLC and are included in this article where relevant.

🛑 No Unauthorized Changes: The PLC program is proprietary to South-Tek Systems and password protected. Do not attempt to alter any controls, programs, or settings without written approval from South-Tek Systems. Unauthorized changes will void all performance specifications and warranties and may cause equipment damage or malfunction.

Home Screen

The Home Screen is the primary operating display and is visible immediately when the PLC powers on. It provides full system control and status at a glance.

Display Element	Description
System On/Off button (upper left)	Main system power toggle. Red = stopped; Green = running. Press and hold to change state.
Current date / time	System clock display
System run hours	Cumulative hours the system has been actively running. Used to track maintenance kit intervals.
Nitrogen Generator Status	Running — system is actively producing nitrogen (not all components run simultaneously); Standby — system is waiting for demand
Nitrogen tank pressure	Live pressure reading from the low-pressure nitrogen storage tank
Nitrogen tank purity	Live O2 purity reading from the storage tank (if O2 sensor option is installed)
Navigation buttons	Menu, Info, and Graph; an Alarms button appears only when an active alarm is present
Booster Controls box	See Booster Controls section below
System Status indicator	Cylinder is Filling — compressor and/or booster is running; Cylinder is Full — cylinders have reached the cut-off pressure

Booster Controls

The Booster Controls box on the Home Screen manages all high-pressure cylinder filling operations independently of the nitrogen generator's run state.

Control / Indicator	Function
Start	Initiates a single cylinder fill (or pack fill) to the cut-off pressure. For auto-refill configurations, initiates automatic fill cycling based on cut-off and cut-on pressures.
Stop	Stops the current fill and resets the bottle fill time counter.
Pause	Pauses the current fill without resetting the bottle fill time. Resume by pressing Start again.
Booster Status	Displays current booster state — see Booster Status Indicators below
Current bottle fill time	Elapsed time since the current single fill was initiated
Bottle fill pressure	Current pressure reading at the cylinder manifold / high-pressure output

Booster Status Indicators

Status	Meaning
Cylinder is Filling	Booster is actively running and filling the connected cylinder(s)
Cylinder is Full	Connected cylinder(s) have reached the cut-off pressure; fill is complete
HPCF is Paused	Booster Pause button was pressed; fill is paused and timer is preserved
HPCF is Stopped	Booster Stop button was pressed; fill is stopped and timer is reset
Emergency Stop	E-stop is active; all system functions are halted
Booster Cooldown	The booster motor has reached a thermal cooldown condition and is temporarily paused. See the Alarms & Troubleshooting article for corrective action.

ℹ Intermittent Operation is Normal: The compressor, nitrogen generator, and booster do not run constantly. Each component starts and stops automatically based on pressure levels in the air tank, nitrogen storage tank, and high-pressure cylinders. This is expected behavior, not a fault condition.

System Run Hours

Run hours are displayed on the Home Screen and count only time the system is actively running — not time spent in Standby. The PLC uses run hours to track when maintenance kits are due and will generate audio and visual alerts when service intervals are reached. Refer to the Filter & Preventive Maintenance article for the full service schedule.

Info Screen

Press the Info button on the Home Screen to view the system's factory-configured cut-off pressure and cut-on pressure for the booster, as well as other key system parameters set at the time of manufacture. This screen is read-only.

Trending Graphs

Press the Graph button on the Home Screen to view historical sensor data as a time-based graph. Use the controls below to navigate the graph display:

Control	Function
Upper / Lower bounds fields	Tap to enter min/max Y-axis values; graph rescales automatically
History	Scroll through historical graph data
Grid	Toggle horizontal gridlines on/off
Graph Options	Access graph type selection and the Data Log function

Main Menu

Press Menu on the Home Screen to access the Main Menu. Enter user password 6557 when prompted. The Factory Settings option requires a separate factory-level password — contact South-Tek Systems if factory access is needed.

Menu Option	Purpose
Sensor Setup / Calibration	View and calibrate installed sensors (factory-calibrated; contact South-Tek before recalibrating)
Alarms / Filter Parameters	Configure alarm setpoints, view alarm and maintenance kit status, reset FRP timers
Cut-In / Cut-Out Parameters	View nitrogen generator and booster suction pressure setpoints (factory set — do not adjust)
Maintenance Menu	Manually toggle individual valves, compressor(s), and booster for diagnostic purposes
Communication Settings	Configure Ethernet / MODBUS TCP/IP and remote access settings
Language	Switch PLC display language between English and Spanish
Factory Settings	South-Tek factory access only — not accessible with the user password

Pressure Cut-In / Cut-Out Parameters

The HPCF-SFI uses two separate sets of pressure setpoints — one for the nitrogen generator and one for the booster suction — to manage automatic operation:

Parameter Set	Function
N2 Generator Cut-Out	When nitrogen storage tank reaches this pressure, the generator enters Standby
N2 Generator Cut-In	When tank falls to this pressure, the generator automatically restarts
Booster Suction Cut-Out	Booster stops when nitrogen suction pressure reaches this level
Booster Suction Cut-In	Booster restarts when nitrogen suction pressure falls to this level

🛑 Do Not Adjust: Both sets of cut-in/cut-out parameters are factory-set for your specific unit configuration. Do not adjust any of these values without direct guidance from South-Tek Systems. Incorrect setpoints will affect purity, flow, and booster operation.

Alarms / Filter Parameters

Access via Menu → Alarms / Filter Parameters. This screen manages alarm setpoints and maintenance kit status tracking:

Feature	Details
O2 High Level setpoint	Alarm triggers when O2 reading exceeds this value (purity below spec)
O2 PPM Max setpoint	Secondary purity alarm threshold in PPM
Low N2 Tank Pressure setpoint	Alarm triggers when storage tank pressure falls below this value
High Dew Point setpoint	Alarm triggers if dew point exceeds setpoint (if dew point sensor is installed)
Alarms Enabled toggle	Master on/off for all on-screen alarms
Local Alarm Audible toggle	Enable/disable the audible buzzer during alarm conditions
FRP Frequency (kit status)	Displays status and last service date for the 1K, 2K, and 5K hour maintenance kits. Press Reset after completing each service to restart the interval counter.
Alarm Details	List of active and recent alarms with trigger date and time
Alarm History / Clear History	Scrollable log of historical alarm events; clear by entering 1111 on the confirmation screen

Maintenance Menu

The Maintenance Menu allows individual valves, the air compressor(s), and the nitrogen booster to be toggled manually for diagnostic and troubleshooting purposes.

⚠ Use with Caution: Always place the system in Off mode before toggling any component in the Maintenance Menu. After diagnostics are complete, reset all components to the Off position before restarting the system to prevent erratic operation or equipment damage.

Communication Settings

Access via Menu → Communication Settings. Configures Ethernet connectivity for MODBUS TCP/IP communication and remote monitoring:

Enter a static IP address in the IP Address field. The Subnet Mask and Gateway fields are not required for intranet access only.
Press Connect to PC. A Connected status confirms the PLC is discoverable on the network.
For remote access via the Unitronics remote monitoring application, a static IP address is also required. Search "Remote Access" on the South-Tek Systems support portal for setup instructions.

ℹ Configure During Commissioning: Network and MODBUS settings should be configured with South-Tek Systems support during commissioning. Contact the service team before making changes to network configuration on a live unit.

Data Logging (Optional)

Units with the data logging option can record sensor values to a micro SD card. Access via Graph → Graph Options → Data Log:

Press Press to Start Data Analysis to begin logging. The log point counter (upper right) will increment. Press again to pause; press Reset Stats to clear values.
To log to SD card: format the card using the Unitronics SD Card Suite software (search "SD Card" on the support portal for installation instructions). Insert the formatted card and confirm SD Card: OK.
Press Press to Log to SD Card. The File # increments and the Log Count resets to 0.
To stop: press Press to Stop SD Logging. Press Eject SD and wait for the Ready signal before removing the card.

Contact South-Tek Systems

Phone: (910) 415-1880

Email / Ticket: support@southteksystems911.zendesk.com