Nor-Lake LogiTemp Walk-In Error Code PSA: Suction Pressure Sensor
PSA means the suction pressure sensor reads shorted, open or out of range on a Nor-Lake walk-in with a Split-Pak system and the LogiTemp controller. Without a trusted suction pressure, the controller cannot manage the expansion valve properly. Write down the code and LED color, check the box temperature and move food if it is climbing.
Medium: the expansion valve control loses a key reading, and the box may warm.
- Code
- PSA
- Maker
- Nor-Lake
- Equipment
- Walk-in coolers & freezers
- Applies to
- LogiTemp / KE2 Evap OEM (Split-Pak systems, A1 refrigerants)
What does Nor-Lake error code PSA mean?
The suction pressure sensor is one of the two readings the KE2 Evap OEM controller uses to run the expansion valve. Together with the suction temperature, it gives the controller the superheat it needs to feed the evaporator correctly. The sensor sits on the suction side of the Split-Pak system, and the controller checks that it gives a reasonable number. When the sensor reads shorted, open or out of range, the controller shows PSA as a three-digit code on the Basic Display. Without a trusted suction pressure the controller cannot manage the expansion valve properly, so the box may warm up or the system may be held back while the alarm is active. The owner's manual says most alarms clear by themselves once the condition ends, which is true here if the cause was a brief loose plug. The causes are a loose plug at the PSA input, a broken wire between the sensor and the controller, a failed sensor input on the board, or a sensor line worn through by vibration or heat.
Affected models and control systems
This applies to the LogiTemp / KE2 Evap OEM controller on Nor-Lake Split-Pak walk-in coolers and freezers with A1 refrigerants.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- PSA on the Basic Display with a yellow or red LED
- Box temperature rising
- Evaporator coil not as cold or frosted as normal
- Compressor held back or cycling oddly
Possible causes
Listed in Nor-Lake's documentation
- Loose plug on the suction pressure sensor at the PSA input
- Broken wire between the Split-Pak sensor and the controller
- Failed pressure sensor input on the KE2 Evap OEM board
- Sensor line worn through by vibration or heat
Other likely causes — what usually sits behind error code PSA on this control. A technician confirms which one it is before any part is replaced.
- Sensor cable rubbing against a pipe clamp near the compressor
- Sensor fitting loose or leaking at the suction line
- Connector corroded by condensation on the cold suction line
Safe checks before calling for service
- Write down the code and which LED is lit, yellow or red.
- Check the box temperature with a thermometer and move food if it is climbing.
- Keep the walk-in door closed as much as you can.
- The owner's manual says most alarms clear by themselves once the condition ends. If PSA stays, call us to schedule service.
How a technician diagnoses error code PSA
- Read PSA and the suction pressure shown by the controller.
- Compare with a gauge on the suction line.
- Inspect the sensor plug, wire and fitting.
- Measure the sensor output and test the board input.
- Replace the sensor, wire or board only after the test.
- Gauge readings on the suction line need certified refrigerant handling.
- The sensor wire passes through the compressor area with heat and vibration.
- The board is wired to live control voltage.
How error code PSA differs from similar codes
SSA reports the suction temperature sensor, the partner reading used with suction pressure. PSA is the pressure sensor only.
Technical reference
- Document
- LogiTemp Electronic Controller System Operations Manual (171527 Rev. A), Alarms & Notifications List pp. 47-51
- Edition
- 171527 Rev. A, 2025 (Refrigerated Solutions Group)
- Models / control
- LogiTemp / KE2 Evap OEM (Split-Pak systems, A1 refrigerants)
- Section
- Alarms & Notifications List, printed pp. 48-52; Troubleshooting Tables from p. 52
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Nor-Lake walk-in cooler & freezer error codes
Can I run the box with PSA?
With close watching. The expansion valve control may be held back, so check the temperature.
Will PSA clear by itself?
If a plug was only briefly loose, yes. A repeat needs testing.
Is PSA a refrigerant leak?
No. It reports the sensor reading, though a gauge helps rule out a real pressure problem.
Need help with Nor-Lake error code PSA?
A technician confirms the cause on site and gives you the price in writing before any work starts.