Quincy 451CS80HCB QT Pro — 5 HP, 80-Gallon Horizontal Two-Stage Air Compressor, 230V 1-Phase

The number that tells you what this machine is: 942 RPM. That is how fast the pump turns, and it is roughly half the speed of the light-duty compressors sold at the same horsepower. A slow-turning pump has less piston travel per hour, less friction, less heat and less noise, and it is the single design decision that separates an industrial compressor from a consumer one. Everything else about this unit follows from it.

It is a 5 HP two-stage QT Pro delivering 17.2 CFM at 175 PSI, on an 80-gallon horizontal receiver, running on 230V, 1-Phase supply — ordinary single-phase shop power, no three-phase service required.

Single-phase, and the circuit it genuinely needs

This is the version of the QT Pro that a small shop can actually install, because it runs on the supply most small shops already have. What it does need is a proper circuit: Quincy specifies a 60 Amp breaker for this machine. That is a serious circuit — considerably more than a welder outlet in a home garage — and it is the single most common reason a purchase like this stalls halfway. Check with your electrician that the panel can carry it before you order, not after the pallet arrives.

A magnetic starter is supplied, which is the correct arrangement on a motor of this size: it gives you proper contactor switching and overload protection rather than a pressure switch trying to make and break the full motor current. The motor itself is an open drip-proof design, which keeps it cool by moving air through it — the trade being that it wants a reasonably clean, dry location rather than a wash bay or a blasting room.

Slow speed, and what it is worth

At 942 RPM the pump makes its air with long, unhurried strokes rather than by spinning fast. The practical results are the ones you notice from across the shop. It is markedly quieter than a high-speed unit of the same rating, which matters when the compressor lives in the same room as the people. It runs cooler, so the oil keeps its properties and the valves do not carbon up as quickly. And the bearings, rings and rods simply accumulate wear more slowly, because wear is a function of distance travelled and this pump travels less of it per hour of air produced.

That is also why the machine is heavy for its horsepower — around 660 lbs. Slow-running compressors need mass and cast iron where a fast one gets away with aluminum and speed. The QT-5 industrial pump is cast iron with finned cooling, running two-piece connecting rods that can be serviced without pulling the crankshaft, which is a repairability detail worth having on a machine you expect to keep for a very long time.

Two stages, 17.2 CFM and 175 PSI

Compression happens in two steps with a high-efficiency finned tube intercooler in between: the first cylinder does the coarse work, the intercooler removes the heat that work created, and the second cylinder takes the cooled, denser air up to 175 PSI. The pressure is the point. Single-stage compressors of this size run out of breath well below that, and the tools that care — impact wrenches on suspension bolts, air-over-hydraulic equipment, anything with a high-pressure rating on the plate — are the tools most likely to be the reason you are buying a compressor at all.

17.2 CFM is a real working supply for a one- or two-bay shop. It will keep an impact wrench, a ratchet and a blow gun happy all day, and it will run a spray gun properly. What it will not do is feed a continuous-consumption tool like a large sander or a blast cabinet indefinitely alongside everything else, so add up what you expect to run simultaneously and talk to us if that total is close.

Will it fit?

Roughly 70" long, 23" wide and 47" tall. The horizontal receiver keeps the machine low, so it slides under shelving or a mezzanine and stays clear of a roller-door track, and it puts the oil sight glass, the drain and the belt guard where you can reach them without a ladder. Give it flat, sound concrete and clear air around the pump and heads — the most reliable way to shorten a compressor's life is to shut it in a cupboard. The tank outlet is 3/4".

Confirming your supply, providing the 60 Amp circuit and disconnect, and providing a floor that will take the weight are the buyer's responsibility. We are happy to be part of that conversation before you order.

Perfect For

• One- and two-bay independent shops on single-phase supply.
• Serious home and hobby workshops where three-phase is not an option and noise matters.
• Tyre and quick-service bays running impact tools all day.
• Small fabrication shops and farm workshops wanting an industrial pump on ordinary power.
• Anyone replacing a screaming high-speed compressor and wanting to hear themselves think.

What is in the box

The complete machine: the QT-5 cast iron industrial pump with its finned tube intercooler and belt guard, the open drip-proof slow-speed motor, the magnetic starter, gauges, oil sight glass, safety relief valve and the ASME-coded 80-gallon horizontal tank, assembled on the receiver ready to wire and pipe. Not supplied: air dryer, aftercooler, electronic drain valve and low-oil shutdown are absent from this build, as are hose, piping and point-of-use regulation.

Specifications

Certification, stated plainly

The tank is ASME coded, and the specification sheet lists UL and CSA on the electrical side. Those are separate things: a pressure-vessel code stamp on the receiver, and safety marks on the electrical components. Neither of them speaks to your installation, and neither is a substitute for whatever your local authority or your insurer requires of a pressure vessel in your building. If a specific listing or an inspection is a condition of your cover, check it against the data plate before you buy rather than afterwards.

Warranty

The machine carries a 1-year factory warranty, which extends to a 3-year "No Bull" warranty under Quincy's own programme and its own conditions — registration, and on several models a maintenance kit purchased with the compressor. We will confirm in writing which conditions attach to this model before you order. Our claims process is set out on the warranty claims page. One rule regardless of the fault: do not take the pump apart before the claim has been agreed, because a stripped pump cannot be assessed.

Freight and delivery

The compressor travels by freight on a pallet within the lower 48 states. At around 660 lbs it needs a forklift or a pallet jack at the delivery end; if you have neither, take terminal pickup and collect it with a trailer, which is what a good many single-bay shops do. Residential delivery is available and carries a residential fee, and the freight itself is quoted live at checkout rather than guessed here.

Check the shipment before you sign for it. Look at the tank, the pump, the motor and the pallet, and record anything you find on the bill of lading in front of the driver — once a clean receipt is signed, damage becomes very hard to claim.