What does Kaeser alarm 0005 A (oil separator temperature) mean?
Short answer: Air temperature at oil separator tank outlet too high. If your Kaeser Sigma Control 2 is showing 0005 A — Oil separator Temperature ⇞, 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?
The maximum air temperature at the oil separator tank outlet was exceeded. Documented checks are the trip-relay line path and the oil separator cartridge for damage.
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?
- Air at the separator tank outlet exceeding its maximum temperature
- Trip-relay line path or a damaged separator cartridge (the documented checks)
- Hot ambient or poor ventilation as a first pass
Can you fix it yourself?
No — beyond cooldown and a ventilation check, stop. This alarm can be fire-safety related; it is not one to reset and rerun.
Step by step — what to try, in order:
- Let the machine cool down.
- Check ambient temperature and ventilation as a first pass.
When do you need a technician — and why?
The documented checks — trip relay wiring and the separator cartridge — go beyond safe operator work, and repeated hot runs against this alarm risk a genuine fire hazard.
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 0005 A — Oil separator Temperature ⇞ mean on a Kaeser Sigma Control 2?
Air temperature at oil separator tank outlet too high. The maximum air temperature at the oil separator tank outlet was exceeded. Documented checks are the trip-relay line path and the oil separator cartridge for damage.
Can I fix 0005 A — Oil separator Temperature ⇞ on a Kaeser Sigma Control 2 myself?
No — beyond cooldown and a ventilation check, stop. This alarm can be fire-safety related; it is not one to reset and rerun.
When does 0005 A — Oil separator Temperature ⇞ on a Kaeser Sigma Control 2 need a technician?
The documented checks — trip relay wiring and the separator cartridge — go beyond safe operator work, and repeated hot runs against this alarm risk a genuine fire hazard. Call an authorized Kaeser technician — inspecting the trip relay wiring and the separator cartridge goes beyond safe operator work.
Verified against service documentation: Kaeser Sigma Control 2 documentation for 0005 A — Oil separator Temperature ⇞ (airsolcan.com)