QRS15HP-150 BM: the base-mount 15 HP, for shops that already own a tank

BM stands for base mount, and it is the whole point of this listing. Everything that makes air is here — the 15 HP airend, the motor, the controller, the enclosure — but there is no receiver underneath it. You bolt this to the floor and pipe it into a tank you already have, or into a receiver you are buying separately and siting where it suits the building rather than where the compressor happens to stand.

That configuration answers a specific problem. A shop adding capacity to an existing compressed-air header usually does not want a second tank taking up another patch of wall; it wants more air feeding the storage it already paid for. A shop with a mezzanine, a plant room or a noise-sensitive layout often wants the receiver in one place and the compressor in another. Neither of those is possible with a tank-mounted machine, and both are straightforward with this one.

Where the saved space and weight actually go

Leaving the receiver out changes the footprint dramatically. The package measures around 45 inches long and weighs about 408 lbs, which is a machine two people and a pallet jack can position rather than a rigging job. It fits through a standard double door. It can go on a mezzanine deck or in a plant room that no tank-mounted unit of this output would ever get into. If your building has an awkward route from the roller door to the compressor's final home, the base-mount build is frequently the difference between an install that happens on a Tuesday morning and one that needs a crane.

Rotary screw behaviour: 100% duty, and what that buys you

These units are produced in Italy by Atlas Copco, and the airend is rated for 100% duty. A piston compressor is rated for a percentage of each hour, and when you exceed it the machine gets hot and its life gets short. A screw compressor at 100% duty has no such ceiling; it is designed to run continuously and to be sized by air demand rather than by rest periods. This one delivers 51 CFM and unloads at 150 psi, driven by a TEFC motor on 208-230/460V, 3-phase power.

Control is load / no-load with a timed shutdown. When demand stops, the machine unloads instead of slamming off, then powers down after the idle timer expires. That sequence is what stops a screw compressor from short-cycling itself to death in a shop where air use comes in bursts. The control panel is UL, cUL and CSA approved and the electrical enclosure is NEMA 1.

What you still have to buy

This is the section most base-mount buyers wish someone had written for them. Because there is no tank in the package, you are responsible for the receiver, its safety fittings, its drain and its inspection paperwork. There is no dryer here either, so any air feeding a spray gun, an air gauge or a pneumatic control valve needs drying and filtration you supply downstream. And you need the interconnecting pipework, isolation valves and a flexible connection at the compressor so that its vibration does not travel into rigid pipe. None of that is exotic, but none of it is in the crate, and the quickest way to a disappointing installation is to discover it on the day.

Serviceability

The oil filter and the air/oil separator are both spin-on elements. That is a small design decision with a long tail: routine service is a filter change a competent technician performs on site in an hour, not a strip-down that puts the machine on a truck. Noise sits at 69 dBA, which for a 15 HP compressor is quiet enough to share space with people, though a base-mount unit bolted to a hard slab will always transmit more into the structure than a tank-mounted one on isolators. Mount it on pads.

Will it fit, and will it run?

Check the electrical supply before anything else. This machine wants 208-230/460V, 3-phase; if the building is single phase, it is not a candidate without a serious conversation with your electrician. Physically, allow for the 45 inch length plus service clearance on the panel side and the cooler side — a compressor packed into a corner with no airflow will trip on temperature in July regardless of how well it was sized. The listing also carries an overall width and height, but both are recorded without units, so we will not print them as though we knew whether they were inches or millimetres; ask and we will pull the dimensioned drawing. Confirming supply, clearances, ventilation and the receiver you intend to pair this with is the buyer's responsibility.

Perfect for

• Shops expanding an existing system that already have a receiver on the header and want more capacity, not more tanks.
• Buildings with a plant room where the compressor and the storage sit in different places by design.
• Second-machine installations where two compressors share one large receiver for redundancy.
• Awkward sites — mezzanines, basements, tight door routes — that a tank-mounted unit simply cannot reach.

What is in the box

Per this listing: the 15 HP TEFC motor and airend in the base-mount configuration, the load / no-load control with timed shutdown, the approved control panel with NEMA 1 protection, and the spin-on oil filter and separator. No receiver, no dryer, no pipework and no electrical disconnect are stated as included. Treat every one of those as your scope unless we confirm otherwise in writing.

Specifications

Approvals, stated plainly

The approval this data actually carries is on the control panel: UL, cUL and CSA, in a NEMA 1 enclosure. That is an electrical approval and nothing more. Because this build has no tank, there is no pressure vessel in the package for anyone to register, and any vessel paperwork your inspector, insurer or plant safety programme wants will attach to the receiver you supply, not to this machine. If you are buying the receiver from us as well, tell us what documentation you need and we will confirm it before the order goes in rather than after.

Shipping and delivery

Palletised freight to the lower 48 states, free of charge. Because there is no tank, this is one of the easier compressors in the range to receive — but it is still a freight shipment, so you need a forklift, a dock, or the willingness to collect from the carrier's terminal. Deliveries to a residential address carry a residential fee. Inspect before you sign: look at the enclosure panels, the cooler fins and the base rails, and write any damage on the bill of lading while the driver is standing there. Signing clean and calling later is how claims get refused.

Warranty

The standard term is 1 year. A 5 year term is available where the machine is commissioned by a factory-authorized start-up, typically charged at $350. On a base-mount install that start-up is more valuable than usual, because the commissioning technician is looking at a system you assembled — your receiver, your pipework, your drain — not just at a factory-built package. Do not open the airend, the separator housing or the control panel before a warranty claim is raised; a machine that has already been apart is a claim that is very hard to win.