Quincy 473D80VCB23M QT MAX 7.5 HP, 80-Gallon Two-Stage Air Compressor (230V, 3-Phase)

Splash lubrication has one failure mode that matters, and this compressor is fitted to catch it. When the oil level in a splash-lubricated crankcase falls far enough, the dipper stops reaching oil and the bearings run dry within minutes. The QT MAX carries a low-oil protection system that shuts the machine down before that happens, backed by an extra-capacity oil reserve that gives you far more margin before the level ever gets close. Together they turn the classic way a shop compressor dies into a service call instead of a replacement.

The rest is straightforward industrial hardware: a two-stage cast-iron pump delivering 22.6 CFM at 175 PSI into an 80-gallon vertical ASME certified receiver, driven by a 7.5 HP motor on a 230V three-phase supply.

QT MAX or QP Pro? The Honest Comparison

Quincy sells two 80-gallon platforms at this power rating and they are not the same design. The QP Pro is pressure lubricated, using a gerotor oil pump and a spin-on filter. The QT MAX, this machine, is splash lubricated but adds low-oil shutdown, an extra-capacity oil reserve, an automatic tank drain and an air-cooled aftercooler.

Which one is right depends on the failure you are trying to avoid. If your compressor runs long continuous cycles under sustained load, pressure lubrication is the more thorough answer. If your problem has been water in the lines, forgotten drain valves and an oil level nobody checks, the QT MAX addresses those directly and protects itself when the checklist slips. Both are honest engineering; they solve different problems.

What the Extra Oil Reserve Actually Does

A larger oil volume is not simply a longer interval between top-ups. Oil in a compressor crankcase is a coolant as much as a lubricant, and a bigger reserve has more thermal mass, so it runs cooler for the same heat input. Cooler oil oxidises more slowly, holds its viscosity longer and leaves less varnish on the rings and bearings. The visible benefit is a longer service interval; the real benefit is that the oil is still doing its job at the end of that interval.

Two-Stage Compression and Heat

The pump compresses in two steps. A large first-stage cylinder does the bulk of the work, the charge passes through a high-efficiency finned intercooler, and a smaller second-stage cylinder finishes it to 175 PSI. Cooling in between is what makes the arrangement efficient: cooled air is denser, so the high-pressure cylinder moves less volume for the same pressure and generates less heat doing it.

Aluminium cylinder heads sit at the hottest point of the pump and shed heat faster than cast iron would, while the cylinders themselves stay cast iron for wear resistance and dimensional stability. Downstream, an air-cooled aftercooler drops the discharge temperature so moisture condenses inside the machine rather than in your pipework, and an automatic tank drain clears what collects in the receiver without anyone remembering to.

Starting and Protection

A magnetic starter is fitted as standard, giving the motor thermal overload protection and starting it under contactor control. The connecting rods use a two-piece design, keeping the reciprocating assembly simple, and the tank is ASME certified with the relief hardware a pressure vessel of this size requires.

Will It Fit?

Vertical receiver, so the floor space is modest and the height is not: 37" long, 24" wide, 74" tall, weighing 720 lbs. Measure the ceiling first, then allow additional clearance above the unit for head and belt access rather than only enough to stand it upright. A flat, level, load-bearing slab is required.

Supply is 230V three-phase. This build is not interchangeable with the other voltage versions, so confirm the voltage at your panel and not from the building's documentation. Quincy directs breaker selection to a certified electrician, because the correct overcurrent device depends on conductor size, run length and local code. The electrical circuit, site preparation and any permits are the customer's responsibility.

Perfect For

• Busy repair shops where maintenance is real but not always on schedule.
• Multi-technician bays running impacts, ratchets and blow guns through the day.
• Tyre, exhaust and general service work on a 230V three-phase supply.
• Buyers replacing a compressor that seized because nobody checked the oil.

What's in the Box

Supplied as a complete tank-mounted machine: two-stage cast-iron pump with aluminium heads, 7.5 HP motor with belt drive and guard, finned intercooler, air-cooled aftercooler, automatic tank drain, low-oil protection system, magnetic starter and the 80-gallon vertical ASME certified receiver. Piping, a disconnect, a dryer and downstream filtration are separate purchases.

Specifications

Certification, Honestly

The tank is ASME certified and the manufacturer's data records a CSA marking with it. Read them separately. A pressure vessel certification concerns how the receiver was built and inspected under a boiler and pressure vessel code; an electrical safety marking concerns the motor and control equipment. One is not evidence of the other, and neither describes the installation in your building.

When the machine arrives, verify what is actually on its data plate. That plate is what an inspector, an insurer or a safety officer will read, and it is the version of the claim that stays with the equipment. Where a particular listing is a condition of your code, your insurance or your employer's standards, confirm it before the unit is connected.

Shipping and Delivery

Ships by freight within the lower 48 states. At 720 lbs, standing on a pallet, it needs a forklift, a dock or a terminal pickup you have arranged; it will not arrive on a parcel van. Deliveries to a residential address carry a residential fee.

Inspect before signing. Check the guards, the aftercooler, the drain fittings and whether the receiver has shifted in its bracing, and write anything you find on the bill of lading in front of the driver. A clean signature is very difficult to argue with afterwards.

Warranty

Cover is a 1-year factory warranty, extending to a 3-year "No Bull" warranty when Quincy's conditions are met, which are handled at the point of sale and generally require the matching maintenance kit to be purchased with the compressor and the unit registered with the manufacturer. The warranty documentation supplied with the machine holds the definitive terms.

Should a fault occur, open the claim before you open the equipment. Disassembly before inspection is the most common reason a genuine claim is refused.