Atlas Copco GA 55 (FF 55⁺) Oil-injected Air Compressor

The Atlas Copco GA 55 is the 55 kW fixed speed oil-injected screw compressor in the GA 30+-90 series, carrying 75 hp of installed motor power. Two branches share the platform: the GA 55 itself and the GA 55+ build with its larger element, each delivered either as a Pack or as a Full Feature unit with the dryer factory fitted. Pressure versions cover 7.5, 8.5, 10, and 13 bar at 50 Hz, while 60 Hz plants select among 100, 125, 150, and 175 psig nameplates. Every figure from the official tables appears below, so a buyer can match branch and pressure version to the duty before requesting a quotation.

Delivery is a single pre-assembled package: screw element, gear transmission, coolers, oil system, and the Elektronikon controller are tested together on one base frame. The machine only needs a level floor, power, and an air outlet to start producing.

Especificaciones técnicas

Capacity follows ISO 1217, Annex C, Edition 4:2009, with FAD referenced to 7 bar on the 7.5 bar build, 8 bar on the 8.5 bar build, 9.5 bar on the 10 bar build, and 12.5 bar on the 13 bar build.

Every version draws on the same 55 kW (75 hp) motor. The Pack tips the scale at 1360 kg (2998 lb) and the Full Feature build at 1685 kg (3715 lb), while the plus branch adds five kilograms at each stage. Sound readings are taken at the work station according to ISO 2151 and ISO 9614, with a 3 dB(A) uncertainty.

60 Hz Versions

For 60 Hz markets the same two branches appear under psig nameplates, measured per ISO 1217 with the footnotes and reference conditions of the 50 Hz tables.

Motor rating, sound level, and weights are identical across the two supply frequencies, which keeps spare parts lists and installation drawings interchangeable for groups that operate plants on both sides of the Atlantic.

The GA 55+ Branch

Behind the unchanged 55 kW (75 hp) motor rating, the plus branch mounts a larger compression element that turns slower for the same output. Flow climbs from 179 to 191 l/s (378 to 405 cfm) on the 7.5 bar build, and the sound pressure level drops two decibels to 69 dB(A). Plants that draw near-full load around the clock get the widest flow band of the 55 kW class from this build.

Service intervals stretch to 8000 hours on the plus branch, supported by Smart Temperature Control that watches the oil circuit with intelligent sensors and keeps it in its ideal window through the seasons. Fewer planned stops per year are the practical result for continuous operations.

Pack and Full Feature Builds

Each branch is offered as a Pack or as a Full Feature unit. The Pack occupies 1680 × 1221 × 1980 mm (depth × width × height) and rolls into position without a special foundation. Choosing Full Feature extends the depth to 2525 mm, because the integrated refrigerant dryer, its filtration, and the electronic condensate drain ride on the same frame, wired and piped before they leave the factory. The dryer holds a pressure dewpoint of 2°C to 3°C (36°F to 37°F) at reference conditions.

Width and height never change between the two builds, so a Pack installation can move to Full Feature later by extending the room along one axis only.

Gear Transmission and Oil Circuit

An enclosed gear train connects the motor to the screw element, holding the designed speed ratio without belts to tension or couplings to align. One synthetic oil circuit lubricates the bearings, seals the element, and carries compression heat to the coolers in a single pass, which keeps the oil system compact and easy to service.

Cooling air sweeps across both the oil cooler and the aftercooler inside a canopy lined with acoustic material on every panel. Daily checks and routine service points gather behind panels on one side at standing height, so the unit can be placed against a wall or lined up in a row.

Where the GA 55 Fits

The 7.5 bar and 8.5 bar builds serve textiles, blowing, and general plant air; the 10 bar build matches assembly lines and packaging; the 13 bar build carries injection molding and high-pressure tool networks. Fixed speed logic rewards sites with level consumption, while operations whose demand swings between shifts should compare the variable speed route, for example the Compresor de aire con inyección de aceite Atlas Copco GA 250 range and the GA 55 VSD of the same series.

GA 55 FAQ

How do the two branches differ?

The plus branch fits a bigger element behind the same 55 kW (75 hp) motor. Output rises from 179 to 191 l/s on the 7.5 bar build, sound falls from 71 to 69 dB(A), and the service interval extends to 8000 hours.

Which pressure version fits my plant?

Pick the lowest version that covers the highest pressure consumer on site: 7.5, 8.5, 10, or 13 bar at 50 Hz, or 100, 125, 150, and 175 psig at 60 Hz.

How much air does the family produce?

Across branches and pressure versions the 50 Hz range spans 136 to 191 l/s (287 to 405 cfm), referenced to ISO 1217, Annex C.

What does Full Feature include?

An integrated refrigerant dryer, filtration, and an electronic condensate drain, factory assembled on the same frame. Depth grows from 1680 to 2525 mm while the other two dimensions stay put.

What does the package weigh?

The Pack weighs 1360 kg (2998 lb) and the Full Feature build 1685 kg (3715 lb); the plus builds add five kilograms at each stage.

Do 50 Hz and 60 Hz units share components?

Motor ratings, noise levels, weights, and the footprint are the same, so drawings and spare parts lists carry over between regions even though each machine is wound for its own supply.