What does Kaeser alarm 0012 A (access doors) mean?
Short answer: Access door open while running. If your Kaeser Sigma Control 2 is showing 0012 A — Access doors, the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
A maintenance door was opened or a cover panel removed while the machine was running, so the controller shut it down.
Which machines show this?
the wide range of current-generation Kaeser rotary screw compressors — ASD, BSD, CSD, DSD, ESD and related series — built since roughly 2011 with the Sigma Control 2, the industrial-PC controller with a text display and RFID access. It reports faults as a four-digit number plus a letter: 'A' messages are alarms that shut the machine down, 'W' messages are warnings or service reminders it keeps running through, with arrows marking whether the value went over or under its limit — so 0015 A is the airend-overheat shutdown while 0013 W just asks for an air filter. Practical tip: the same subsystem often has a W and an A code (0004 W before 0022 A on the separator); acting on the W message is how you avoid the A shutdown.
What causes it?
- A maintenance door opened or cover panel removed while the machine was running
- Door interlock switch faulty if the alarm shows with everything closed
Can you fix it yourself?
Yes — close the doors, refit the panels, acknowledge, and restart. It is doing exactly what it should.
Step by step — what to try, in order:
- Close all maintenance doors and refit all cover panels.
- Acknowledge the alarm and restart.
When do you need a technician — and why?
If the alarm appears with all doors verified closed, the interlock switch needs checking — a safety device that service should test, not one to bridge out.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does 0012 A — Access doors mean on a Kaeser Sigma Control 2?
Access door open while running. A maintenance door was opened or a cover panel removed while the machine was running, so the controller shut it down.
Can I fix 0012 A — Access doors on a Kaeser Sigma Control 2 myself?
Yes — close the doors, refit the panels, acknowledge, and restart. It is doing exactly what it should.
When does 0012 A — Access doors on a Kaeser Sigma Control 2 need a technician?
If the alarm appears with all doors verified closed, the interlock switch needs checking — a safety device that service should test, not one to bridge out. If the alarm appears with all doors verified closed, call service to check the door interlock switch.
Verified against service documentation: Kaeser Sigma Control 2 documentation for 0012 A — Access doors (airsolcan.com)