BelAire 338HL 7.5 HP 80-Gallon Two-Stage Air Compressor, Dual-Voltage 3-Phase

The useful thing about the 338HL is that it does not force you to know your building's exact service voltage before you order. One machine wires into either 208V or 230V 3-phase supply, so the two commonly encountered low-voltage three-phase services in North American commercial buildings are both covered by the same part number. If you have ever had a piece of equipment turn up wound for the wrong one, you know why that matters.

Underneath that convenience is a proper industrial compressor: a 7.5 HP motor, a belt-driven two-stage pump with cast iron cylinders and aluminum heads, an aftercooler, an 80-gallon horizontal ASME receiver, and a 175 PSI ceiling.

One machine, either three-phase service

Commercial buildings do not all deliver the same low three-phase voltage, and the difference is not always documented on the panel schedule you were handed. A dual-voltage machine removes that risk from the purchase decision entirely. It also matters if you ever move: a shop that relocates, or a business that buys equipment for one building and later consolidates into another, does not have to re-motor the compressor.

BelAire's recommendation for this unit is a 40 amp breaker. For a 7.5 HP motor that is a moderate circuit, which is the practical dividend of running on three phase rather than one. As with any motor installation, the actual amp draw should be confirmed with a certified electrician against your service, your conductor run and your local code — BelAire deliberately publishes it that way rather than as a single number, and having it checked before delivery is the customer's responsibility.

Why a three-phase motor is easier on everything it touches

This is the part that rarely makes it into a specification table, and it is the reason experienced shops prefer three phase when they can get it.

A single-phase motor makes its torque in pulses, because the supply crosses zero twice a cycle. It also needs starting components — capacitors and, in many designs, a centrifugal switch — that exist only to get the rotor turning and that are among the most common failure points on a compressor motor. A three-phase motor has none of that. The three windings overlap so that torque is essentially continuous, so it starts itself with no auxiliary circuit at all.

The consequences you actually notice are less vibration through the frame and the mounting feet, a quieter and less percussive start, lower starting current for the same power, and one entire category of failure that simply cannot occur because the parts are not there. Over the life of a machine that runs several times an hour, every working day, that adds up.

A magnetic starter is fitted from the factory, which gives the motor proper overload protection. One first-start check: three-phase rotation depends on the order of the supply conductors, and a pump turning the wrong way makes noise and almost no air. Confirm the flywheel turns in the direction of the arrow on the guard before you leave it running; swapping any two supply legs reverses it.

Confirm the rating pressure before you size your air tools

Delivered air on this model is published as 22.3 CFM, but the pressure that figure is measured at is published two different ways — and an airflow rating means nothing without its rating pressure.

The manufacturer's feature list and our specification database both state 22.3 CFM at 100 PSI. The product overview text supplied with this model states 22.3 CFM at 175 PSI. Those describe meaningfully different machines: delivered air always falls as pressure rises, so the same figure quoted at the higher pressure implies a stronger pump.

If you are sizing this compressor against a specific continuous-draw tool, confirm the delivered air and its rating pressure with us in writing before you order and we will get both from the manufacturer's current data sheet. The maximum pressure is settled either way: 175 PSI.

Will it fit?

Horizontal tank, so plan for length rather than height: 71" long, 24" wide and 49" high, weighing 538 lbs. It wants a level, solid floor and it should sit on all its feet without rocking. Leave access at the pump end for belt and oil work, and do not park it so close to a wall that the flywheel cannot draw cooling air.

Perfect For

• Commercial shops with three-phase service that do not want to verify the exact supply voltage before ordering.
• Businesses that expect to move or that run more than one building on different low three-phase voltages.
• Busy multi-bay service and repair operations where the compressor cycles many times an hour and motor longevity is a real cost.
• Fabrication shops running sustained air demand rather than short bursts.

In the box

• Solid cast iron two-stage pump, belt driven, with aluminum heads
• Aftercooler
• 80-gallon horizontal ASME tank with safety valve
• Magnetic starter, factory fitted
• Start/stop pressure switch controls
• Oil sight glass
• Fully enclosed belt guard
• Pressure gauge
• Manual air tank drain

Not included: an air dryer. BelAire recommends the CPXHT25 for this compressor, sold separately. A low oil shut-off is not listed as fitted on this model, so the sight glass is the only oil-level warning you get.

Specifications

Motor and supply

Pump and air

Tank and dimensions

Certification, said plainly

The receiver is built and stamped to the ASME pressure vessel code and carries a safety valve. That is the certification BelAire claims for this machine, it is about the tank, and it is verifiable.

We do not hold a North American third-party electrical safety listing from an accredited testing laboratory for this unit. A pressure vessel code stamp and an electrical safety listing are different documents covering different hazards, and one does not imply the other. Some insurers, some corporate facility standards and some local electrical inspectors require the electrical listing by name. If there is any chance yours does, settle it before you order and ask us in writing — we would rather answer the question now than have a 538 lb machine fail an inspection in your building.

Freight and receiving

Freight shipment to the lower 48 states, free of charge.

You must be able to take it off the truck. That means a forklift or a loading dock at the delivery address, or arranging terminal pickup and collecting it yourself. Residential delivery is available and carries a residential fee. Inspect the shipment before signing: check the skid for shift, the tank ends for dents, the guard for distortion and the trailer deck for oil. Note anything you find on the delivery paperwork, photograph it while the driver is still there, and only then sign. Damage found after a clean signature is very difficult to claim.

Warranty

A 2-year bumper-to-bumper factory warranty covers all components, with no additional purchase required. Record the serial number as the crate comes apart and keep it with the invoice.

One standing warning: do not disassemble the pump, motor or pressure switch before a claim has been opened. Stripping a component to prove it failed is the most reliable way to lose the cover on that component. Report the fault first. Then keep to the oil and belt tension schedule, and drain the tank — the drain on this model is manual, and an undrained receiver rusts from the inside where nobody can see it.