Quincy rotary screw compressors speak three dialects depending on the machine, and none of them is a numbered code. QSI-series industrial machines with the standard QSI control panel show terse text messages: ESTOP, OVERLOAD, HIGH TEMP, SUMP HAT, PRES FAULT, each documented in the QSI manual's fault table. QGS 20-30 hp machines use the compact INFOLOGIC controller, which has no text faults at all: it communicates with LEDs and pictographs, a flashing temperature symbol, a motor symbol, an e-stop symbol, a service wrench, plus small scrollable screens such as d.06 for service-timer hours. Larger QGD 40-60 hp and QGS 40-100 hp machines run the Airlogic2 controller with icon-and-text conditions and an Event History menu that records every trip.
How to read the display. On the QSI panel, search the exact wording shown; "sump" means the fluid separator vessel and "fluid" is Quincy's word for the compressor lubricant. On INFOLOGIC, read which pictograph is lit or flashing and then the alarm LED: steady means a warning, flashing means a shutdown. The temperature pictograph flashing is the 221 °F element outlet warning; the alarm LED flashing with it is the 230 °F shutdown. On Airlogic2 the rule is the same, a lit alarm LED is a warning and a flashing one a shutdown, with the condition spelled out on screen. Its element outlet warning is factory-set at 235 °F and the shutdown at 248 °F, but these are programmed values and your machine's exact trip points can differ. Read the Event History before any service call; it tells the technician what happened in what order. Warnings clear themselves when the condition passes; shutdowns need the cause corrected and the unit reset.
One honest note. Web pages listing "Quincy fault code E-xx" numbers are describing controllers these machines do not have. If you searched a number and landed here, match the message or symbol on your display to the tables below instead.
What is safe to do yourself. Cooler cleaning, filter checks, room ventilation and fluid level are operator work and each page lists them in order. The manuals keep the electrical enclosure strictly off-limits to unqualified hands, note that the emergency stop does not make the machine voltage-free, and route service timer changes through the authorised distributor. Every message in the tables below links to its own page with the documented thresholds, the safe first steps, and when it takes a technician, citing the Quincy manual it was verified against.
Five Quincy codes to know first
- HIGH TEMP (Quincy QSI series (QSI standard controls)): High discharge temperature shutdown.
- OVERLOAD (Quincy QSI series (QSI standard controls)): Main motor overload tripped.
- Element outlet temperature shutdown (alarm LED flashing) (Quincy QGS 20-30 (INFOLOGIC controller)): High element outlet temperature shutdown.
- Element outlet temperature shutdown (Quincy QGD 40-60 / QGS 40-100 (Airlogic2 controller)): High element outlet temperature shutdown.
- ESTOP (Quincy QSI series (QSI standard controls)): Emergency stop button pressed.