Description
The Atlas Copco ZT 55 is the 55 kW air-cooled machine of the ZR/ZT 55-90 oil-free family, a fixed-speed compressor that brings certified oil-free air to plants without a cooling water circuit. The compression chambers run completely free of oil, the package carries the ISO 8573-1 CLASS 0 (2010) certification verified by TÜV, and the Full Feature build integrates the IMD adsorption dryer inside the same package.
Three pressure versions at 50 Hz and three at 60 Hz cover free air delivery from 122.3 to 157.8 l/s, and a high ambient temperature variant takes intake air up to 50 degrees Celsius. Cooling is by air alone, so the compressor installs wherever the production needs it.
Where the ZT 55 Sits in the Oil-Free Range
The ZR/ZT 55-90 family serves the plants whose oil-free demand fits a compact package instead of the larger ZR/ZT 110-275 class, and the ZT 55 carries 55 kW of installed motor power at the entry of the range. The letter Z marks the oil-free architecture: the precision-cut rotors never touch, so the compression chamber needs no lubrication and no oil can reach the air stream. Where the demand profile swings, the ZT 55 VSD of the same rating adjusts its speed continuously instead of loading and unloading.
Atlas Copco pioneered oil-free air technology over sixty years and became the first manufacturer awarded CLASS 0 certification. The ZT 55 brings that standard into the air-cooled 55 kW class, and the package arrives as a complete all-in-one installation: place it on a flat floor, connect the power line and the air outlet, and push the start button.
Two Branches, One Platform
Two names describe the branches of the ZT 55, and each adds one fact:
- Standard — the compressor package delivers oil-free air for networks with external air treatment downstream, with the stainless steel pre-cooler dissipating the heat of compression into the room air.
- FF — Full Feature: the package integrates the IMD adsorption dryer, so dry air leaves the machine directly with no external energy spent on regeneration.
Every version combines with both branches, and the 8.6 bar band adds the HAT high ambient temperature variant. Plants with a cooling water main on site pick the ZR 55 of the same rating.
Technical Specifications of the ZT 55
The table below condenses the ZT 55 into its headline figures:
| Parameter | Value |
|---|---|
| Model | Atlas Copco ZT 55 |
| Compressor type | Oil-free rotary screw, air-cooled |
| Capacity control | Fixed speed |
| Installed motor power | 55 kW / 75 hp |
| Pressure versions | 7.5 / 8.6 / 8.6 HAT / 10 bar(e) at 50 Hz; 7.25 / 8.6 HAT / 9 / 10.4 bar(e) at 60 Hz |
| Free air delivery | 122.3-157.8 l/s by version (7.3-9.5 m³/min / 259-334 cfm) |
| Sound level | 76 dB(A) at the work station |
| Air purity | ISO 8573-1 CLASS 0 (2010), TÜV certified |
| Motor protection | Totally enclosed IP55 TEFC, IE3 efficiency class |
| Frequency | 50 Hz and 60 Hz |
Rated Data at 50 Hz
Unit performance is measured according to ISO 1217, annex C, edition 4 (2009). The 7.5 bar version is measured at 7 bar, the 8.6 bar version at 8 bar and the 10 bar version at 9 bar:
| Version | FAD (l/s) | FAD (m³/min) | FAD (cfm) | Noise |
|---|---|---|---|---|
| ZT 55 – 7.5 | 146.3 | 8.8 | 310 | 76 dB(A) |
| ZT 55 – 8.6 | 132.7 | 8.0 | 281 | 76 dB(A) |
| ZT 55 – 8.6 HAT | 122.5 | 7.4 | 260 | 76 dB(A) |
| ZT 55 – 10 | 122.3 | 7.3 | 259 | 76 dB(A) |
The 7.5 bar version leads the series at 146.3 l/s (310 cfm), and the 10 bar band delivers 122.3 l/s (259 cfm). The HAT row of the 8.6 bar band is the high ambient temperature variant, rated for sites where the intake or cooling air exceeds the limits of the standard version.
Rated Data at 60 Hz
The 60 Hz versions cover three bands from 7.25 to 10.4 bar(e), and the motor is rated at 75 hp. The measurement pressures follow the same rule as at 50 Hz:
| Version | FAD (l/s) | FAD (m³/min) | FAD (cfm) | Noise |
|---|---|---|---|---|
| ZT 55 – 7.25 | 157.8 | 9.5 | 334 | 76 dB(A) |
| ZT 55 – 8.6 HAT | 129.5 | 7.8 | 274 | 76 dB(A) |
| ZT 55 – 9 | 139.2 | 8.4 | 295 | 76 dB(A) |
| ZT 55 – 10.4 | 129.3 | 7.8 | 274 | 76 dB(A) |
The 7.25 bar version tops the whole series at 157.8 l/s (334 cfm). The noise level is the A-weighted emission sound pressure level at the work station, measured according to ISO 2151: 2004 using ISO 9614/2, with a total uncertainty value of 3 dB(A).
Dimensions and Weight
The standard branch and the Full Feature branch differ in length, because the Full Feature carries the integrated dryer:
| Branch | Weight | Dimensions (L × W × H) |
|---|---|---|
| ZT 55, Standard | 1,900 kg / 4,189 lb | 2,180 × 1,450 × 2,184 mm (85.8 × 57.1 × 86.0 in) |
| ZT 55, Full Feature | 2,520 kg / 5,556 lb | 2,880 × 1,450 × 2,184 mm (113.4 × 57.1 × 86.0 in) |
No foundations are required for either branch. The package installs directly on the flat floor of the compressor room, and the air-cooled layout removes the cooling water main, the water treatment and the condensation handling from the installation plan.
Class 0 Air Purity, Verified by TÜV
The ZT 55 belongs to the first compressor range in the industry certified oil-free according to ISO 8573-1 CLASS 0 (2010). TÜV type-tested the range with the most rigorous methodologies available, measuring all possible oil forms across a range of temperatures and pressures, and found no traces of oil at all in the output air stream. CLASS 0 is the most stringent class of the standard: the total oil concentration is as specified by the equipment user or supplier and more stringent than class 1.
That certification is what makes the ZT 55 the default choice where a single trace of oil costs a batch: food and beverage lines running fermentation, packaging and filling, electronics plants cleaning chips and boards, petrochemical operations in extreme heat and humidity, and pharmaceutical production from tablet coating to bottling.
Air Cooling and the HAT Variant
Air cooling defines the ZT branch of the family. The stainless steel pre-cooler transfers the heat of compression to the room air through a low-noise radial fan, which keeps the package free of any water dependency and holds the installation simple. The sound pressure level reads 76 dB(A), two decibels above the water-cooled ZR sibling.
Where the ambient conditions turn extreme, the 8.6 bar HAT variant carries the high ambient temperature rating: the machine accepts intake and cooling air up to 50 degrees Celsius and is mandatory above 40 degrees Celsius ambient, which keeps oil-free production running in tropical plants and hot process halls through the whole summer.
Full Feature: The Integrated IMD Adsorption Dryer
In the ZT 55 Full Feature, the IMD adsorption dryer eliminates the moisture before it enters the air net. The dryer uses the heat of the compressor for regeneration, so no external energy is needed to dry the air, and the savings against a conventional dryer are large. The pressure drop through the dryer is minimal, which cuts the operating cost again, and the whole drying function lives inside the compressor package instead of beside it.
Control and Monitoring
The Elektronikon unit controller runs the compressor and the integrated dryer from one control system. The high-resolution color display shows the running conditions with clear icons and intuitive navigation, monitors the maintenance status, and raises pro-active service indications, alarms for malfunctions and safety shutdowns. The display supports 31 different languages, and built-in remote control and notification functions come as standard with ethernet-based communication.
SMARTLINK and Options
The option list of the ZT 55 tailors the package to the plant:
- Monitoring and protection bundle — anti-condensation heaters, SPM bearing monitoring and PT 1000 sensors in the windings and bearings.
- SMARTLINK — online data monitoring of the compressed air system with warning indications and maintenance scheduling.
- PDP sensor and low load kit — Full Feature options for dew point verification and stable part-load running.
- Anchor pads, wooden case packaging, material certificates, test certificate and witnessed performance test — for controlled installation and documented acceptance.
- Teflon-free elements and purge kit for dry air during standstill — for specified coating materials and tropical environments.
Applications of the ZT 55
Food and beverage plants run the ZT 55 for fermentation, aeration, transportation, filling and capping, where the CLASS 0 certification removes the contamination risk from the audit trail. Electronics manufacturers use the clean, dry air for removing microscopic debris from chip and board surfaces, and petrochemical sites value the machine’s ability to run in extreme temperatures and humidity conditions around the clock.
Pharmaceutical production completes the picture, from fermentation and tablet coating to packing and bottling, where 100 percent oil-free air protects both the process and the brand. Where the demand profile fluctuates heavily, the plant adds the ZT 55 VSD of the same rating next to this fixed-speed machine, and growing networks step up to the ZT 75 of the same platform.
Service and Support Around the ZT 55
The ZT 55 is built for long overhaul intervals, few service interventions and minimal maintenance cost, and every machine is tested before delivery to ensure it meets the specifications. A global service operation with field service engineers across 160 countries backs the installed base, and genuine Atlas Copco parts keep the package at its rated performance.
Seadweer supplies genuine Atlas Copco spare parts and service kits for the ZT 55 and its Full Feature branch, and the parts coverage follows the same platform index as the ZT 55 VSD and the larger ZT 90. Send us the compressor model together with the parts you need, and the correct items are confirmed with the quotation in one pass.
FAQ
What does the ZT 55 deliver at 7.5 bar?
The 7.5 bar version delivers 146.3 l/s at 50 Hz, which equals 8.8 m³/min or 310 cfm, measured at 7 bar according to ISO 1217 annex C, edition 4 (2009). At 60 Hz the 7.25 bar version reads 157.8 l/s (334 cfm).
Is the ZT 55 air-cooled?
Yes. The ZT letter marks the air-cooled branch of the ZR/ZT family: a stainless steel pre-cooler and a low-noise radial fan reject the heat of compression into the room air, so no cooling water main is needed. The sound level reads 76 dB(A), and the water-cooled equivalent is the ZR 55.
How oil-free is the air?
The ZT 55 carries the ISO 8573-1 CLASS 0 (2010) certification verified by TÜV, the most stringent class of the standard. TÜV testing found no traces of oil at all in the output air stream across the tested range.
What does the Full Feature build add?
FF integrates the IMD adsorption dryer inside the compressor package. The dryer regenerates with the heat of the compressor, so no external energy is needed, and the package weight grows from 1,900 kg to 2,520 kg while the length grows from 2,180 mm to 2,880 mm.
What is the HAT version for?
The HAT variant of the 8.6 bar band is the high ambient temperature rating: it accepts intake and cooling air up to 50 degrees Celsius and is mandatory above 40 degrees Celsius ambient. Plants in tropical climates and hot process halls pick the HAT row to keep the machine within its design limits through the hottest season.
How loud is the ZT 55?
The sound pressure level at the work station reads 76 dB(A) on every version at both frequencies. The value follows ISO 2151: 2004 with the ISO 9614/2 method and carries a total uncertainty value of 3 dB(A).
Lars Fuglsang –
Our building had no cooling water main, so the air-cooled ZT 55 was the practical route to class 0 air. The package sits on the plant floor at 76 dB(A), holds 7.5 bar across two shifts, and the Full Feature dryer delivers dry air straight out of the machine. Seadweer matched the model and our pressure to the right version in one reply.