Quincy 4103D12VCB23M QT MAX - 10 HP, 120 Gallon Vertical, Two-Stage, 230V 3-Phase

Most air compressors are not allowed to run continuously, and most product pages do not tell you so. They carry an unstated duty cycle - run this many minutes in each hour, rest for the remainder - and a shop that ignores it cooks the pump slowly over a couple of years. The QT MAX is rated for 100% duty cycle. It is designed to run for as long as the demand lasts, which is a different machine from one that merely has a big motor.

Underneath that rating: a splash-lubricated cast iron two-stage pump turning at deliberately modest speed, 35 CFM at 175 PSI, a 120 gallon vertical ASME receiver, and a 10 HP motor on 230 Volt 3-phase supply with a factory-fitted magnetic starter.

Two discrepancies in our own data, declared up front

Model code. Three of our sources - the product title, the description heading and the specification block - say 4103D12VCB23M. The page web address and one paragraph inside the current description say 2103D12VCB23M. We hold both and we are not going to guess. Send us the code from your paperwork and we will confirm the exact build before anything is ordered.

Automatic tank drain. The feature list and the description say this unit has an automatic electronic tank drain. The specification field for the electronic drain valve says it has none. One of those is wrong and we cannot tell which from what we hold, so we are telling you rather than quietly printing the better-sounding version. Ask us to confirm it in writing if it affects your decision.

What a 100% duty cycle rating actually means

Duty cycle is the proportion of each hour a compressor is permitted to spend actually pumping. A machine rated at, say, three quarters is not defective; it is built on the assumption that it gets a quarter of every hour to shed heat. Exceed that regularly and the consequences are entirely predictable - hotter oil, thinner oil film, faster valve fatigue, and a pump that is worn out well before its notional life.

A 100% rating removes that constraint. It is achieved not by magic but by margin: a larger oil reservoir, cooling designed for sustained rather than intermittent operation, and a pump geared to run at lower speed so it generates less heat in the first place for the same delivered air. Running slower is also why a machine like this is noticeably less tiring to work next to than a small compressor screaming to keep up.

What it does not mean is that maintenance is optional. Quincy attributes a pump life in the region of 50,000 hours to this design, and that figure assumes oil changes, a clean cooler and an intake filter that has been looked at this year. Continuous rating is permission to work the machine hard, not permission to ignore it.

Sizing and installation

35 CFM at 175 PSI covers several technicians on air tools, or one sustained consumer such as a blast cabinet or a spray booth, with the 120 gallon tank taking the peaks.

The vertical format keeps the floor plan small: about 40 inches by 30 inches, standing around 75 inches tall, and 1,000 lbs on the pad. Height is the constraint to check first, along with every doorway and roller shutter on the route in. Set it on level, solid concrete and leave clearance on all sides, because a machine rated to run continuously needs air moving over its coolers to actually do so. Confirming the floor, the clearances and the access route is the customer responsibility.

Supply is 230 Volt 3-phase, the commonest three-phase service in an independent workshop. The magnetic starter with thermal overload is fitted at the factory. Quincy records the breaker requirement as consult a certified electrician; the conductor sizing depends on your run length and local code, and it is worth settling before the machine is built.

Specifications

Perfect For

• Shops where the compressor never really stops - production sanding, continuous blasting, a booth in daily use.
• Fabrication and welding shops running plasma alongside hand tools.
• Second-shift operations, where a duty-cycle-limited machine simply will not survive the hours.
• Buildings on 230 Volt 3-phase that want the continuous rating without a voltage conversion.

Overkill for intermittent work. If your compressor runs for ten minutes an hour, a smaller machine will do the job and cost far less to install.

What Is In The Box

Assembled at the factory: two-stage pump, motor, belt drive and guard on the 120 gallon vertical tank, with aftercooler, intercooler, magnetic starter, low oil cut-off switch and oil sight glass in place. Warranty documentation accompanies the machine.

Not included: electrical supply and disconnect, pipework beyond the 1 inch tank outlet, downstream filtration or drying, vibration pads, and consumables for the first service. The EWK-4 maintenance kit is a separate purchase and is the item the extended warranty depends on - buy it with the compressor if you plan to take that option. No air dryer is fitted.

Certification, stated honestly

Quincy lists an ASME tank and UL and CSA marks for this unit. Those certify the machine as manufactured, which is what you want them to do.

They do not certify what you build around it. Whether your feeder, disconnect, overcurrent protection and ventilation comply is your electrician judgement and, where permits apply, your inspector. If an insurer or an authority having jurisdiction wants documentation, ask us before ordering and we will get the manufacturer file to you rather than let you find a gap at sign-off.

Shipping and delivery

Freight to the lower 48 states, priced live at checkout against the ZIP code you enter so you see the real cost to your address. Residential delivery carries a residential fee. A commercial address with a dock or a forklift costs less; terminal pickup costs less still.

Unloading is your responsibility. The truck reaches the kerb and stops there. Arrange a forklift or a dock for 1,000 lbs, or book terminal pickup and arrive with equipment that can handle it.

Inspect before signing. Look over the crate, the tank, the coolers, the pump and the motor, and record anything wrong on the bill of lading before the driver leaves. A clean signed receipt is very hard to argue with afterwards.

Warranty

Standard cover is a 1-year factory warranty. Quincy also offers an extension: purchase the EWK-4 maintenance kit at the time of sale and register the machine within the manufacturer registration window, and the package becomes two years with a 3-year pump warranty, including onsite parts and labour.

Those are the manufacturer terms and they are revised from time to time, so ask us to confirm the current conditions in writing before you rely on them. And whatever the symptom, raise the claim before anything is dismantled - an opened pump, motor or starter is extremely hard to warrant. Call us, keep every part, photograph what you found.