Quincy 5103D12HCA20M QP MAX 10 HP Two-Stage Air Compressor, 208V

A compressor rated for 100% duty is a different machine from one that merely survives hard use, and that rating is the reason to look at the QP MAX package. The 5103D12HCA20M is a 10 HP two-stage unit built around a 1750 RPM industrial motor and a heavy cast-iron pump with aluminum heads, mounted on a 120-gallon horizontal receiver and wired for 208V 3-phase service. Quincy puts pump life beyond 60,000 hours. Everything else on this page is in service of those two numbers.

What a 100% duty cycle rating actually means

Duty cycle is the most misread figure in compressor specifications. A machine rated at half duty is designed to run for part of any given period and cool down for the rest of it; put two people on sanders and it will run past that limit, get hot, and lose oil condition long before it loses pressure. A 100% rating means the design assumes the pump can keep turning without a mandatory rest — the cooling, the bearing loads and the lubrication are specified for it.

Why the shaft speed is the number to check

The motor turns at 1750 RPM, and slow is the whole point. Piston speed sets ring temperature, ring temperature sets wear, and wear is what eventually ends a reciprocating compressor. Halving shaft speed does far more for pump life than any amount of marketing about materials, and it is why an industrial compressor and a big-box compressor with the same capacity on the label are not comparable machines. The slow shaft also produces a lower, less fatiguing noise, which matters when the compressor shares a building with people.

The pump is heavy-duty cast iron with aluminum heads and graphite cylinder and head gaskets. Stainless steel reed valves with bumpers handle the millions of open-and-shut cycles the pump asks of them, and a high-efficiency fin and tube intercooler drops the air temperature between stages so the second stage receives cooler, denser air.

The protection package

Continuous duty is unforgiving of small faults, so several protective devices come as standard. The magnetic starter provides motor thermal overload protection, dropping out the contactor when current exceeds what the motor should draw. A low oil shut-off stops the machine before the pump can run without lubrication. A spin-on oil filter keeps abrasive material out of the bearings, which matters in a machine whose job involves inhaling shop air all day. Together these are the difference between a compressor that fails and a compressor that stops.

Will It Fit?

The unit is a horizontal 120-gallon receiver, 78 inches long, 28 inches wide and 55 inches high, weighing 850 lbs dry. Plan for service access rather than to the outline: belt guard, oil sight glass and filter all need to be reachable with the machine in place, and the cooling fan needs clear room air rather than its own exhaust. Discharge is a 3/4-inch tank outlet, and maximum working pressure is 175 PSI.

Power is 208V 3-phase. Measure your panel rather than assuming from the equipment already installed, because three-phase shop supplies come at more than one voltage and they are not interchangeable. The magnetic starter is included. Breaker and conductor sizing is a job for a certified electrician working from your actual service and run length — that is Quincy own instruction, and it is more useful than a published number that cannot know your building. Checking the supply, the doorway, the access route and the floor before you order is the buyer responsibility.

Perfect For

• Two and three-bay service shops where the compressor is expected to keep up with everybody at once.
• Fabrication and metal finishing, where continuous-draw tools punish a duty-limited machine.
• Agricultural and municipal workshops running long unattended sessions.
• Any shop replacing a compressor that got hot rather than one that wore out — that is a duty cycle problem, and this is the answer to it.

What Arrives

You get the compressor assembled: two-stage cast-iron pump and motor on the horizontal receiver, with the magnetic starter, the spin-on oil filter, the stainless steel reed valves, the graphite gaskets and the fin and tube intercooler all fitted at the factory. The documentation we hold does not list oil, hose, air treatment, a dryer, a regulator or an isolation valve as included, so budget for those separately, and tell us in advance if any of them decides your commissioning date.

Specifications

Two Details to Confirm Before You Order

Two details are published differently by different sources, and both figures appear below with the source of each.

How the pump is lubricated. The manufacturer feature list and the description on this page both call this a fully pressure-lubricated machine with a positive-displacement oil pump feeding the crankshaft, bearings and rods. The specification data records the oil system as splash lubricated instead. Those are two different designs, not two ways of saying the same thing. If the lubrication system is part of why you are buying this compressor, ask us and we will get it confirmed by Quincy in writing before you order.

The tank drain. Published details differ here too: the feature list and the specification table say an automatic electronic tank drain is fitted, while one specification line says it is not. Ask us and we will confirm it with Quincy the same way.

Neither point affects the capacity, the receiver, the electrical supply or the warranty, all of which read the same across every published source.

Certification, Stated Plainly

ASME, UL and CSA marks are recorded on the specification sheet. The ASME mark is a pressure vessel certification: it covers the receiver, its design, its material and how it was built, and it is what a workplace inspector or an insurer will look for on a tank of this capacity. The electrical marks apply to the motor and control components. None of them certifies the air the machine produces, none of them satisfies a local permit requirement, and none of them replaces any periodic inspection your jurisdiction may require of a pressure vessel. Establish what is expected where you are before installation, not after.

Shipping and Delivery

The compressor travels as freight inside the lower 48 states, and the cost is worked out live at checkout for the address you give us rather than being averaged into the price. Sort the unloading out first. There is no version of this delivery that a driver and a customer manage between them, so the destination needs a forklift or a dock — and if it has neither, terminal collection is the sensible route and we can set that up. Say plainly whether the address is residential, too: carriers price a residential delivery differently and it carries a residential fee.

Then inspect it on the pallet before you put your name on anything. Look for guards that have been bent, a broken gauge, oil where it should not be, and any corner of the receiver that has met a forklift blade. Write what you see on the bill of lading in front of the driver. Noted damage is a claim that gets paid; damage found after a clean signature usually is not.

Warranty

Cover is a 1-year factory warranty from Quincy, extending to the 3-year No Bull warranty when the compressor is registered with Quincy and maintained with Quincy kits. Do the registration when the machine arrives — the extension is conditional on it and there is no way to backdate the paperwork. And the standing rule with any warranty claim: talk to us before the pump or the starter is opened up. A partly dismantled machine is the most common reason a manufacturer declines to pay, and it is entirely avoidable.