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Error code · Kolpak · Walk-in coolers & freezers

Kolpak Walk-In Cooler Error Code EXTERNAL ALARM 2: Main AUX2 Input Active

EXTERNAL ALARM 2 appears when the Main AUX2 input is set to EXT ALARM and its digital input goes active. Whatever device is wired to AUX2 is signaling a condition. Press ENTER to silence the alarm for one hour, then trace what is connected.

Medium · inspection needed

Medium: an outside input is reporting a condition that the controller cannot describe.

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Code
EXTERNAL ALARM 2
Maker
Kolpak
Equipment
Walk-in coolers & freezers
Applies to
ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)

What does Kolpak EXTERNAL ALARM 2 mean?

On an ArcticFox controller the Main board offers several auxiliary inputs, and each has a mode setting. For the second one, AUX2 IN MODE is set to EXT ALARM when an installer wants an outside contact to raise an alarm on the display. The controller simply watches that contact. If the digital input becomes active, it shows EXTERNAL ALARM 2 in the Alarms menu. It has no way of naming the device or judging how serious the matter is, which is why the manual describes the condition only in terms of the setting and the input. The alarm remains for as long as the input stays active. Silencing with ENTER mutes it for an hour, after which it sounds again if nothing changed. For this reason the first question is always what the AUX2 wiring goes to.

Affected models and control systems

ArcticFox OEM Controller with Deluxe Display on Kolpak walk-ins. This alarm belongs to the Main AUX2 input and is listed in the Alarms menu on page 16.

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

  • EXTERNAL ALARM 2 text in the Alarms menu
  • Audible alarm until silenced
  • A connected device showing its own warning
  • Alarm sounding again an hour after ENTER is pressed

Possible causes

Likely causes — what usually sits behind EXTERNAL ALARM 2 on this control. A technician confirms which one it is before any part is replaced.

  • Device wired to AUX2 reporting a genuine condition such as a switch tripping
  • Relay contact on that device sticking so AUX2 stays active
  • AUX2 IN MODE set to EXT ALARM during setup on an input that has no device
  • Damaged insulation or a pinched wire shorting the AUX2 circuit

Safe checks before calling for service

✓ What an operator can do
  1. Press ENTER to silence the alarm for 1 hour. It returns if AUX2 is still active.
  2. Ask the installer or check the job notes for what is connected to AUX2.
  3. Look at that device from the outside for a tripped indicator or warning lamp.
  4. Report the alarm text, the device if you identified it, and the time the alarm started.

How a technician diagnoses EXTERNAL ALARM 2

  1. Confirm AUX2 IN MODE reads EXT ALARM in the controller settings.
  2. Identify and inspect the device wired to AUX2.
  3. Meter the AUX2 terminals to confirm whether the input is active, and which way the contact closes.
  4. Lift the field wire to see whether the alarm clears, separating a wiring problem from a real signal.
  5. Repair the device or wiring, or correct the mode if the input was never meant to be an alarm.
! Leave this to a technician
  • Checking the input terminals means opening the controller enclosure with power present.
  • The connected device may protect equipment, and bypassing it to quiet the alarm can hide a genuine problem.
  • The mode setting must match what was wired, which only the installer's records or a technician can confirm.

Technical reference

Document
ArcticFox Deluxe Display - Original Instructions, Installation, Operation and Maintenance Manual
Edition
Part No. 500002385-4, 5/23
Models / control
ArcticFox OEM Controller with Deluxe Display (Kolpak walk-ins)
Section
ArcticFox OEM Controller - Alarms Menu, p.16
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.

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Related Kolpak walk-in cooler & freezer error codes

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EXTERNAL ALARM 2Questions about Kolpak EXTERNAL ALARM 2
Does EXTERNAL ALARM 2 mean the controller is bad?

No. It reports that the AUX2 input is active, which usually points to the device wired there.

Will pressing ENTER clear it?

It silences the sound for one hour. If the input is still active, the alarm sounds again.

How is this different from EXTERNAL ALARM 1 or 3?

Each number names a different Main auxiliary input. The behavior is the same, but the wiring behind each one is different.

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