Quincy Air Compressor 10 HP 120 Gallon Two Stage 208V 3 Phase

The Quincy QP MAX 10 HP two-stage compressor is built for shops that need continuous air production rather than a machine that has to stop and cool down. The 5103D12HCA20M combines a heavy-duty cast-iron pump with aluminum heads, a 1,750 RPM industrial motor, and a 120-gallon horizontal receiver. Quincy rates the pump for more than 60,000 hours of life, while the 100% duty cycle allows continuous operation under demanding workloads. The unit runs on 208V three-phase power, measures 78" L × 28" W × 55" H, and weighs 850 lbs.

The slow 1,750 RPM pump speed helps reduce piston speed, heat, and wear compared with faster reciprocating designs. Inside, stainless steel reed valves with bumpers handle repeated cycling, while the fin-and-tube intercooler reduces air temperature between compression stages. A spin-on oil filter continuously removes abrasive particles from the lubricant, and the low-oil shutdown protects the pump if lubrication drops below the required level. The magnetic starter adds motor thermal overload protection, helping the compressor shut down when a problem occurs instead of allowing a fault to damage the machine.

The QP MAX is a strong fit for busy automotive repair shops, fabrication facilities, agricultural operations, municipal workshops, and other environments with sustained compressed-air demand. Its horizontal receiver is particularly useful where ceiling height is limited, while the 175 PSI maximum working pressure and 3/4" tank outlet support demanding shop applications. Plan for service clearance around the belt guard, oil sight glass, filter, and cooling fan, and have a certified electrician size the electrical connection based on your actual 208V three-phase service.

What a 100% Duty Cycle Rating Actually Means

Duty cycle is one of the most misunderstood figures in compressor specifications. A machine with a 50% duty rating is designed to run for part of a given period and then have time to cool down. Put two people on sanders and it can quickly be pushed beyond that intended cycle, increasing heat and oil degradation long before the compressor actually loses pressure.

A 100% duty cycle means the compressor is designed for continuous operation without a mandatory rest period. The pump's cooling system, bearing loads and lubrication system are all designed around that workload. In a busy shop, that distinction matters: the compressor can keep up with sustained demand instead of relying on downtime to recover.

Why Shaft Speed Is the Number to Check

The motor runs at 1,750 RPM, and that relatively low speed is intentional. In a reciprocating compressor, piston speed affects ring temperature, ring temperature affects wear, and wear ultimately affects pump life. Lower shaft speed reduces the mechanical and thermal stress placed on those components, which is why two compressors with similar capacity ratings can have very different designs and expected service lives.

The slower-running pump also produces a less aggressive operating sound, which can be an advantage when the compressor shares a building with people.

The pump uses a heavy-duty cast-iron construction with aluminum heads, along with graphite cylinder and head gaskets. Stainless-steel reed valves with bumpers are designed to withstand the repeated opening and closing cycles of continuous operation. A high-efficiency fin-and-tube intercooler reduces air temperature between stages, helping the second stage receive cooler, denser air.

The Protection Package

Continuous-duty operation leaves little room for small faults to become big ones, which is why several protective components are built into the package.

The magnetic starter provides motor thermal overload protection, disconnecting the contactor when current exceeds the motor's intended operating range. A low-oil shutoff stops the compressor if the oil level becomes unsafe, helping prevent operation without adequate lubrication. The spin-on oil filter helps keep contaminants out of the lubrication system and away from critical pump components.

Together, these systems are designed to prevent a developing problem from becoming a catastrophic failure. In other words, the goal is for the compressor to stop when something is wrong rather than keep running until something breaks.

Will It Fit?

This is a 120-gallon horizontal receiver measuring 78 inches long, 28 inches wide and 55 inches high, with a dry weight of approximately 850 lbs. Don't plan around the machine's dimensions alone. Leave sufficient service clearance so the belt guard, oil sight glass and filter can be reached without moving the compressor, and make sure the cooling fan has adequate access to unrestricted room air.

The tank outlet is 3/4 inch, and the maximum working pressure is 175 PSI.

Electrical supply is 208V, 3-phase, with the magnetic starter included. Do not assume your existing shop power is compatible simply because you already have three-phase equipment; three-phase systems are available at multiple voltages, and they are not interchangeable.

Quincy does not specify a universal breaker or conductor size for this installation. Its guidance is to have a certified electrician determine the requirements based on your actual electrical service and run length. That's the right approach because those requirements depend on the installation rather than the compressor alone.

Before ordering, verify the electrical supply, doorway dimensions, access route, floor capacity and required service clearance. Those installation checks are the buyer's responsibility — and much easier to resolve with a tape measure before delivery than with an 850-lb compressor sitting in the wrong place.

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 specifications are reported differently across the published sources, so we are flagging both rather than guessing.

How the pump is lubricated. The manufacturer's feature list and the description on this page identify the compressor as fully pressure-lubricated, with a positive-displacement oil pump supplying the crankshaft, bearings and connecting rods. However, the specification data lists the lubrication system as splash lubricated. These describe two different lubrication systems, so they should not be treated as interchangeable wording.

The tank drain. There is a similar discrepancy regarding the tank drain. The feature list and specification table indicate that an automatic electronic tank drain is included, while another specification line states that it is not.

Certification, Stated Plainly

The specification sheet records ASME, UL and CSA marks. The ASME certification applies to the pressure vessel — including its design, materials and construction — while the electrical certifications apply to the applicable motor and control components.

These certifications do not certify the quality of the compressed air, replace local permitting requirements, or eliminate any inspection or recertification requirements that may apply to pressure vessels in your jurisdiction.

Before installation, confirm the requirements with the applicable local authority, workplace inspector or insurer. It is much easier to address compliance requirements before the compressor is installed than afterward.

Shipping and Delivery

The compressor ships by freight within the lower 48 states, with shipping calculated at checkout based on the delivery address rather than averaged into the product price.

Arrange unloading before the compressor ships. At approximately 850 lbs, this is not a shipment that a driver and customer can safely move by hand. Plan for a forklift or loading dock at the delivery location. If neither is available, terminal pickup may be the more practical option, and we can help arrange it.

Be sure to identify the address as residential when applicable. Carriers charge a separate residential-delivery fee.

When the compressor arrives, inspect the shipment carefully before signing the delivery paperwork. Check for bent guards, damaged gauges, oil leaks or marks on the receiver that could indicate contact with handling equipment. If you find damage, document it and have it recorded on the bill of lading while the driver is present.

Warranty

The standard coverage is a 1-year factory warranty from Quincy. The published terms also identify an extended 3-year No Bull warranty when the compressor is registered with Quincy and maintained using qualifying Quincy maintenance kits.

Complete the registration promptly after delivery rather than leaving it until later. If the extended coverage is conditional on registration and maintenance requirements, those requirements should be followed from the start.

And if a warranty issue occurs, contact us before opening the pump, motor or starter or attempting repairs. Do not dismantle the equipment before the claim has been evaluated. Keeping the machine intact, retaining removed parts if any work has already been performed, and documenting the issue gives the manufacturer the best opportunity to assess the claim.