What does a flashing alarm LED mean on a Quincy QGD or QGS compressor?
Short answer: General alarm on the Airlogic2 controller. If your Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller) is showing Alarm LED lit or flashing (general alarm), 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 lit alarm LED indicates a warning condition and a flashing LED indicates a shutdown; the manual directs the operator to the controller's screens for the specific condition.
Which machines show this?
Quincy QGD 40-60 hp and QGS 40-100 hp rotary screw compressors with the Airlogic2 display controller, including Full Feature packages with the integrated refrigerated dryer. Like Quincy's smaller INFOLOGIC machines, these display icons and text messages, not numbered fault codes — a lit alarm LED means a warning, a flashing one a shutdown, and the specific condition is spelled out on the controller's screens and logged in the Event History menu. Warning and shutdown levels for temperatures are programmed values with factory settings, so your machine's exact trip points can differ. Two habits the manual insists on: the emergency stop does not make the machine voltage-free, and service timer changes go through the authorized distributor.
What causes it?
- A lit alarm LED signals a warning; a flashing one signals a shutdown
- The specific condition — temperature, overload, service — is spelled out on the controller's screens, not by the LED itself
Can you fix it yourself?
The LED is a pointer, not the problem — read the actual message on the main screen first, press stop before inspecting anything, and depressurize before touching any component.
Step by step — what to try, in order:
- Read the specific warning or shutdown message on the controller's main screen before doing anything
- Press the stop button before any inspection; never rely on the machine staying stopped
- Follow the depressurization procedure (open the air vent) before touching any component
- Address the displayed condition (temperature, overload, service) per its own procedure
When do you need a technician — and why?
Beyond a routine service reminder or an obvious ventilation or e-stop issue, the conditions behind this alarm involve the pressurized fluid system or the high-voltage cabinet — authorized-provider territory.
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 Alarm LED lit or flashing (general alarm) mean on a Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller)?
General alarm on the Airlogic2 controller. A lit alarm LED indicates a warning condition and a flashing LED indicates a shutdown; the manual directs the operator to the controller's screens for the specific condition.
Can I fix Alarm LED lit or flashing (general alarm) on a Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller) myself?
The LED is a pointer, not the problem — read the actual message on the main screen first, press stop before inspecting anything, and depressurize before touching any component.
When does Alarm LED lit or flashing (general alarm) on a Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller) need a technician?
Beyond a routine service reminder or an obvious ventilation or e-stop issue, the conditions behind this alarm involve the pressurized fluid system or the high-voltage cabinet — authorized-provider territory. Call an authorized Quincy service provider whenever the displayed condition is anything other than a routine service reminder or an obvious ventilation or e-stop issue.
Verified against service documentation: Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller) documentation for Alarm LED lit or flashing (general alarm) (manualslib.com)