Chicago Pneumatic QRS7.5HP-1 TM: a 7.5 HP rotary screw that runs on single-phase power

Almost every rotary screw compressor of this size assumes your building already has three-phase service. This one does not. The QRS7.5HP-1 TM is wired for 208-230V, 1 Phase supply, so a workshop on ordinary single-phase power can run a continuous-duty screw compressor without first paying a utility to bring in a new service — normally the largest single line item in a compressed-air project, and the one that turns a two-week job into a two-month one.

The rest is the standard QRS package: an oil-injected rotary screw airend on a 60 Gallon horizontal receiver, rated 100% duty, running at 64 dBA, with a maximum working pressure of 150 psi. Chicago Pneumatic's rotary screws are built in Italy by Atlas Copco, described in this product's own listing as the world's largest air compressor manufacturer.

Two flow ratings, and we are not choosing between them for you

This product carries two different figures for delivered air at the same pressure. That number decides whether the machine keeps ahead of your tools or falls behind them, so here are both, with the source of each, rather than the flattering one on its own.

• The product heading states 26.1 CFM @ 150 PSI.
• The feature list on the same product states 21.2 CFM at 150 psi.

The gap is roughly a fifth of the machine's output — the difference between two technicians on impact guns being comfortable all afternoon and being marginal by mid-morning. We will not average them and we will not quietly print the higher one. Tell us which tools you intend to run and we will confirm the rated delivery of the exact unit we would ship you, in writing, before you place the order. It is a two-minute question for us and a very expensive assumption for you.

Why continuous duty is the specification that matters

A piston compressor is rated for a percentage of the hour. Run it harder and it overheats, so it stops, and your air pressure sags while it cools. This machine is rated 100% duty: the rotors mesh and turn continuously, there is no reciprocating mass slamming to a halt thousands of times a minute, and the airend is designed to run for as long as the shop is drawing air.

In practice that changes how a bay feels rather than how a spec sheet reads. Nobody waits for pressure to recover before pulling the next wheel. Air-hungry work — sanding, blasting, spraying, a long run on a ratchet — stops being something you schedule around the compressor. It is also why the noise figure matters so much on a machine like this: at 64 dBA it can live inside the workshop rather than being exiled to an outbuilding, and every metre of pipe you save between the tank and the tool is pressure you keep.

Will It Fit? Power, space and siting

Checking supply, floor and ventilation before you order is the buyer's responsibility, and on this model the power question is the easy one for once.

• Electrical supply: 208-230V, 1 Phase. Give those figures to your electrician along with the machine's nameplate before delivery day; conductor sizing and breaker rating depend on the length of your run and on local code, and that is an electrician's call, not ours.
• Tank: 60 Gallon, horizontal. A horizontal receiver keeps the whole assembly low and lets it sit against a wall or under a mezzanine, which is often what decides the installation in a garage with a roller-door track overhead.
• Footprint: overall length 57". Overall width and height are held in our data as bare numbers with no unit attached, so we have not printed them — a number without a unit is not a measurement. If the footprint is what decides your installation, ask us and we will get the dimensioned drawing.
• Weight: 362 lbs on a level, solid pad. This is not a machine to shim.
• Tank outlet: 1/2". Size the shop pipework from that, not from the outlet of whatever you are replacing.
• Ventilation: a rotary screw rejects the heat it makes. It needs air movement around the enclosure and somewhere for warm air to go, especially in a closed compressor room.

Perfect For

• Single-phase workshops — the reason this variant exists. If your building has no three-phase supply and you have been told a screw compressor is out of reach, it is not.
• Two- and three-bay independent shops running several air tools through a full working day.
• Body and paint work, where a compressor that stops to cool shows up in the finish.
• Anyone who has outgrown a piston machine and is tired of waiting on the pressure gauge.

What's in the Box

The compressor arrives as a package: the rotary screw airend and drive motor mounted on the 60 Gallon horizontal tank, ready for a supply connection and shop pipework.

Not included, and worth planning for before the pallet arrives: electrical installation and the circuit itself, downstream filtration or drying, shop plumbing from the 1/2" outlet, and the factory authorized start-up described under Warranty below. We have listed only what this product's own data states is supplied — if your order depends on an accessory being in the crate, confirm it with us in writing first.

Specifications

Without an electronic drain, clearing condensate from the receiver is a manual job somebody has to remember every week. It is the most common way a sound tank is ruined, and it costs nothing to put on the maintenance board.

Approvals, stated plainly

We will describe the documentation position for this model rather than badge it with initials it has not earned. This product's data does not carry a third-party safety listing for the packaged machine, and we are not going to imply one exists. What it does carry is a manufacturer's specification and a factory commissioning programme.

That distinction matters to a specific group of buyers: some insurers, some fleet and facility standards, and some local electrical or pressure-vessel inspectors ask for independent listing documents on hard-wired shop equipment, and a manufacturer's own declaration is not the same document. If that applies to your site, ask us before you order and we will establish in writing what paperwork ships with this model.

Shipping and delivery

This compressor travels as palletised freight within the lower 48 states. This item ships free, so there is nothing to add at checkout.

Decide how it comes off the truck before you order. At 362 lbs it needs a forklift, a dock, or a pallet jack with level ground at the delivery point; the driver's responsibility ends at the tailboard. If you have none of those, take terminal pickup and collect from the carrier's yard. A home address is a residential delivery and carries a residential fee — better known now than argued about on the day.

Inspect the machine before you sign. Look at the enclosure, the tank, the panel and the fittings with the driver still there, and write any damage or shortage onto the bill of lading before your signature goes on it. Damage recorded at delivery is a claim; damage found after a clean signature is usually a conversation you lose.

Warranty

The machine carries a 1 year standard warranty. A 5 Year term is available instead, conditional on the compressor being commissioned through a factory authorized start-up, for which this listing gives a typical fee of $350.

Two honest caveats on that. The fee is described as typical rather than fixed, and it is charged by the commissioning engineer rather than by us, so treat it as an indication and ask for a current quotation. And a start-up is worth having on its own merits: rotation direction, oil level and control settings checked by somebody who does it every week is how a rotary screw ends up with a long, uneventful life.

If a fault develops, stop the machine, isolate the supply and call us before anything is opened. An airend that has already been taken apart is close to impossible to assess, and a claim on a dismantled unit is a very difficult case to make. Photographs of the fault as found are worth more than any description written afterwards.