What does Gardner Denver advisory 301 change separator mean?
Short answer: Separator element pressure drop warning. If your Gardner Denver AirSmart controller is showing ADVISORY #301 CHANGE SEPARATOR, 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?
Differential pressure across the separator element exceeded 8 PSIG — the element is loading up and should be changed before it forces a shutdown at 15 PSIG.
Which machines show this?
Gardner Denver rotary screw compressors fitted with the first-generation AirSmart microprocessor controller — a wide range of oil-injected packages, including VFD-equipped variable-speed units where the controller supervises the drive. The first-generation AirSmart reports problems as numbered codes: SHUTDOWN #1xx and #2xx faults that stop the machine, and ADVISORY #3xx warnings that let it keep running while flagging maintenance. That numbering matters when you search — the later AirSmart G2 dropped the numbers and displays plain-text fault names instead, so a numbered code on the screen tells you that you are on the earlier controller. Shutdowns clear with Stop/Reset once the machine has stopped; advisories acknowledge with the Enter key.
What causes it?
- Separator element pressure drop passed the 8 PSIG warning threshold — the element is loading up
- Normal element life reached; it will keep plugging until the 15 PSIG shutdown at #202
Can you fix it yourself?
The advisory itself is just an acknowledgment away — but the real fix is ordering the correct Gardner Denver element now and scheduling the change before the machine forces the issue with a shutdown.
Step by step — what to try, in order:
- Order the correct Gardner Denver separator element for your model
- Schedule replacement before the 15 PSIG shutdown threshold is reached
- Press Enter on the controller to acknowledge the advisory
When do you need a technician — and why?
The element lives inside the pressurized air/oil separator tank, which has to be fully depressurized before opening — that's why the swap is a technician visit, not a filter change.
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 ADVISORY #301 CHANGE SEPARATOR mean on a Gardner Denver AirSmart controller?
Separator element pressure drop warning. Differential pressure across the separator element exceeded 8 PSIG — the element is loading up and should be changed before it forces a shutdown at 15 PSIG.
Can I fix ADVISORY #301 CHANGE SEPARATOR on a Gardner Denver AirSmart controller myself?
The advisory itself is just an acknowledgment away — but the real fix is ordering the correct Gardner Denver element now and scheduling the change before the machine forces the issue with a shutdown.
When does ADVISORY #301 CHANGE SEPARATOR on a Gardner Denver AirSmart controller need a technician?
The element lives inside the pressurized air/oil separator tank, which has to be fully depressurized before opening — that's why the swap is a technician visit, not a filter change. Have a technician replace the element — the separator tank must be depressurized before opening.
Verified against service documentation: Gardner Denver AirSmart controller documentation for ADVISORY #301 CHANGE SEPARATOR (best-aire.com)