HPCF Series — Alarms & Troubleshooting – South-Tek Systems

Applies to: HPCF Series — 1, 2, 4, and 6 K-cylinder/day configurations

Does NOT apply to: HPCF-SFI — see HPCF-SFI Alarms & Troubleshooting

This article covers PLC alarm codes, active alarm indicators, and step-by-step troubleshooting for the most common HPCF Series fault conditions. When multiple causes are listed for a symptom, investigate the simpler solutions first. If the issue persists after following these steps, contact South-Tek Systems support.

🛑 Safety First: Before performing any inspection or maintenance related to a fault condition, power down the generator and isolate it from all electrical and pneumatic supplies. Fully depressurize the system before opening or working on any component. Wear appropriate PPE at all times.

PLC Alarm Codes

When an alarm condition is present, the red Alarm button appears on the Home Screen. The PLC displays alarm codes that indicate the type of fault. The three common alarm codes are:

Code	Alarm	Immediate Action
E1	Filter Alarm	Replace filter elements. See the Filter & Preventive Maintenance article for procedures and part numbers.
E2	Booster Stall	Disable the booster stall check in the PLC. If stalling persists, the booster may be due for service — contact South-Tek Systems.
E3	Purity Alarm	Purge the nitrogen storage tank to atmosphere while maintaining a minimum tank pressure of 70–80 PSIG. See Low N2 Purity troubleshooting below.

ℹ Alarm History: All alarm events are logged in the PLC with timestamp, duration, and deactivation time. To review: press Menu → Alarms/Filter Parameters → Alarm button → Alarm History. Up to 256 events are stored. See the Controls & Operation article for navigation details.

System Does Not Start / Generator Not Cycling

Probable Cause	Corrective Action
System is in Stopped mode (Start/Stop button is red)	Press the Start/Stop button and hold until it turns green
Booster not started	Press the Booster Start button on the Home Screen
Emergency stop (E-stop) engaged	Verify the E-stop button is not engaged; twist to release if depressed
Low voltage or amperage	Check the electrical source; verify supply voltage and frequency match the unit nameplate
Circuit breaker tripped	Reset the circuit breaker; investigate root cause if it trips repeatedly
Fuse blown	Replace the blown fuse(s) on the electrical panel (7-amp time delay fuse)
Low incoming air pressure	Check the air compressor output and the internal air pressure regulator; verify pressure is within 100–150 PSIG range
High-pressure cylinder already full	Connect cylinders that require filling, or drain and reconnect the existing cylinder
PLC error or faulty control panel	Inspect for loose wires or tubing; check PLC for active alarms; reset if needed. Contact South-Tek Systems if the fault persists.
Defective wiring	Inspect all wiring connections in the electrical enclosure

Generator Running Continuously (Not Entering Standby)

Probable Cause	Corrective Action
Cut-out pressure set incorrectly	Contact South-Tek Systems to confirm and restore the factory cut-out setpoint
Defective wiring between pressure transducer and touchscreen	Inspect wiring connections at the pressure transducer and the PLC input terminal
Excessive nitrogen system leak	Perform a full leak check on all piping, fittings, and connections using leak detection solution; repair all leaks found
Cycle pressure too low	Check the incoming air source and internal air pressure regulator; verify pressure is set to the design specification

Low Nitrogen Purity (E3 Alarm)

Probable Cause	Corrective Action
System requires N2 purge (after startup or prolonged shutdown)	Purge the nitrogen storage tank to atmosphere while maintaining a minimum tank pressure of 70–80 PSIG; allow the generator to run and restabilize purity before using product
Product flow rate too high	Reduce downstream nitrogen demand to allow the generator to catch up and restore purity
Exhaust port blocked	Inspect the PSA exhaust tube for blockages, kinks, or excessive backpressure; clear or correct as needed
O2 sample port valved off	Confirm the O2 gas sample valve from the storage tank to the generator is fully open
O2 analyzer malfunction or out of calibration	Validate sensor accuracy by connecting a known test gas to the generator sample line. If inaccurate, contact South-Tek Systems before recalibrating.
Inadequate incoming air pressure or flow	Verify compressor output pressure and flow; inspect and replace filters in the air filtration train if dirty
Faulty process valves or seals (cross-contamination between beds)	Test each process valve individually using the PLC Maintenance Menu; replace any valve that is not operating correctly
Contaminated or depleted adsorbent (CMS) in PSA beds	Inspect the molecular sieve in the PSA columns; the sieve should fill to the top of each column. Top off or replace if depleted or contaminated. Contact South-Tek Systems for guidance.

⚠ Do Not Fill Cylinders During a Purity Alarm: If an E3 alarm is active, do not connect or fill cylinders until purity has been confirmed at or above specification. Filling with off-spec nitrogen may render cylinders unsafe for use.

Low Nitrogen Storage Tank Pressure

Probable Cause	Corrective Action
Clogged inlet filters	Inspect and replace particulate and coalescing filter elements; see Filter & Preventive Maintenance article
Insufficient compressor feed pressure or flow	Verify air compressor output; confirm air inlet regulator on the generator is set to the design specification
System leak (nitrogen side)	Perform leak check using leak detection spray or ultrasonic leak detector on all fittings, valves, and connections; confirm the N2 tank drain wedge valve is fully closed
Bad process valve — not building bed pressure	Test each process valve individually via the PLC Maintenance Menu
Disconnected or leaking pneumatic line	Inspect all pneumatic lines and fittings; reconnect or replace any that are loose or damaged
No air pressure to pilot valves	Verify pilot air supply pressure is adequate at the valve manifold

Booster Not Functioning Properly (E2 Alarm)

Probable Cause	Corrective Action
Ball valve on N2 tank outlet is closed	Open the ball valve on the nitrogen tank outlet
Booster supply air regulator set too low	Adjust the booster supply air regulator to 100 PSIG
N2 tank pressure too low to reach booster cut-in	Allow the nitrogen generator to run and build storage tank pressure to the booster cut-in value before expecting the booster to start
Emergency stop active	Confirm E-stop is not engaged; twist to release if depressed
Booster start active but pause engaged	Confirm the Booster Start button is active and the Pause button is not active on the Home Screen
HPCF stall check enabled	Disable the booster stall check in the PLC; if the booster is stalling due to wear, schedule booster service with South-Tek Systems
AMP drive 1 solenoid inoperative	Replace AMP drive 1 solenoid; contact South-Tek Systems for the correct part
AMP drive 2 pneumatic valve inoperative	Replace AMP drive 2 pneumatic valve; contact South-Tek Systems for the correct part
Booster fills continuously	Disable continuous fill mode if enabled, or inspect for a faulty pressure switch; contact South-Tek Systems if the condition persists
Booster due for service (700–1,000 run hours)	Contact South-Tek Systems to arrange booster swap or service; see Filter & Preventive Maintenance article for the hot swap program details

ℹ Booster Maintenance Note: The HPCF Series booster is an air-driven amplifier and is not field-serviceable. Service must be performed at the South-Tek Systems facility. South-Tek recommends maintaining a spare booster on-site for rapid swap when service is due. See the Filter & Preventive Maintenance article for the hot swap program details.

When to Contact South-Tek Systems

Contact South-Tek Systems support when any of the following apply:

Persistent low purity or low flow after completing all troubleshooting steps above
Booster stall (E2) that does not clear after disabling the stall check
Unidentified alarm codes or error conditions not covered in this article
Mechanical or electrical faults that require advanced diagnostics or component replacement
Any condition that requires opening or servicing internal PSA bed components
Booster service is due (700–1,000 run hours) and a replacement booster is needed

Contact South-Tek Systems

Phone: (910) 415-1880

Email / Ticket: support@southteksystems911.zendesk.com