Screw Compressor ATMOS ST 55 Vario+ FD input power 55 kW, capacity 8.9 m³/min, 7.5 bar, Vario Danfoss, FD integrated dryer, Plus (higher discharge), LOGIK 26-S, 7-year warranty
Code: ST55VARIOPLUSFD
Product detailed description
Screw Compressor ATMOS ST 55 Vario+ FD
The ATMOS SmartTronic ST 55 Vario+ FD is the top configuration in the 55 kW class — Vario + Plus + integrated Fusion Dryer. Continuous output 0–8.9 m³/min at 7.5 bar + dry air (dew point +5 °C ÷ -20 °C). Weight 1290 kg.
Maximum from the 55 kW class in a single integrated station. Investment return typically 2–3 years compared to an equivalent system: Standard + separate dryer + separate inverter + filtration.
ST 55 Vario+ FD Configuration
Specifically, this variant consists of:
Main features
Construction and Screw Block ST 55 Vario+ FD
A150 screw block, 5th generation + 55 kW IE3 + Danfoss VLT + integrated Fusion Dryer + compressed air filter + cyclone separator. MANN+HUMMEL filtration ISO 8573. Modulating valve for highest control accuracy.
Fusion Dryer FD — integrated into the body
The most economical drying method capable of achieving negative pressure dew point values. The dryer is integrated into the compressor, equipped with compressed air filtration and utilizes waste heat and process air. Operation is fully automated, controlled by humidity measured at the outlet. The required pressure dew point can be set in the range of +5 °C to −20 °C on the compressor controller.
Compressed Air Filtration — Standard in FD
In machines with fusion drying, a compressed air filter and a cyclone separator are installed as standard. Filtration ensures high air quality at the outlet for the most demanding industrial applications — food industry, medical technology, fine pneumatics, paint shops. The cyclone separator removes moisture and oil, and the compressed air filter meets the purity class according to ISO 8573. MANN+HUMMEL filter cartridges for long service life.
Danfoss VLT Drive + Modulating Valve
Danfoss VLT industrial frequency drive precisely adapted for oil-injected screw compressors. Variable speed control according to current consumption. Slow start-up protects the block and motor from hydraulic shock. Elimination of starting currents.
Modulating valve allows for continuous power regulation of the compressor based on the current compressed air consumption at the outlet. This leads to electricity savings and reduced machine load. The modulating valve is a simple and effective solution for saving energy, reducing mechanical and electrical stress, and extending lifespan. Together with the VLT drive, achievable savings of 20–30% electricity.
Technical data ST 55 Vario+ FD
BASIC DATA | |
| Nominal motor power | 55 kW (IE3, 94% efficiency) |
| Operating pressure (variants) | 7.5 / 8.5 / 10 / 13 bar |
| Discharge (FAD at 7.5 / 8.5 / 10 / 13 bar) | 8.9 / 8.7 / 8.1 / 7.6 m³/min |
| Rated voltage | 400 V / 50 Hz |
| Motor protection class | IP 55 / ISO F |
| Noise level | 71 dB(A) |
| Compressed air outlet | G 1 1/4" |
| The temperature of the working environment | +5 ÷ +40 °C |
| Weight | 1290 kg (with Fusion dryer) |
| Dimensions (L × W × H) | 1876×1288×1761 mm |
EXECUTION | |
| Screw block | A 150 V. generation (N-profile rotors, City University) |
| Drive | Multi-V belt (with gearbox) |
| Frequency converter | Danfoss VLT — smooth regulation |
| Fusion dryer | Integrated (dew point +5 to -20 °C, incl. filter + cyclone separator) |
| Control unit | LOGIK 26-S (MODBUS/RTU, ATMOS Care) |
| Guarantee | 7-year UNLIMITED + optional ATMOS Plus 48 months |
| Manufacturer | ATMOS Chrást, CZ (tradition since 1899) |
Who is ST 55 Vario+ FD suitable for
The ST 55 Vario+ FD is for very demanding operations with 250+ people with variable consumption + the highest demands on air quality. Pharmaceuticals, sensitive electronics, large automotive plants with automated lines.
Typical applications
- Large pharmaceutical plants — GMP standard
- Sensitive electronics — PCB manufacturing, SMT lines, semiconductors
- Large automotive plants (Škoda Auto, Hyundai)
- Large food processing plants (sugar factories 250+ people)
- Premium quality printing plants (offset + UV + lamination)
- Central station with ARCHON for 3–5 machines
7-year UNLIMITED warranty ATMOS PLUS 48 months
We simply believe in our machines.
- No flat fees, no service contracts
- ATMOS Plus extends the warranty up to 4 years beyond the standard
- Original parts and timely professional service
- Remote management via ATMOS Plus application
Optional Equipment — Heat recovery up to 72%
Using ATMOS heat recovery exchangers, it is possible to reuse up to 72% of the electrical energy consumed during compressed air production. The energy is recovered in the form of heat from the oil circuit. Investment return typically under 1 year.
ATMOS heat recovery exchangers are supplied as a compact external unit for connection to the compressor's oil circuit and the water circuit (heating, domestic hot water heating).
Construction details ST 55 Vario+ FD
LOGIK 26-S + ATMOS Care Control
LOGIK 26-S controls the compressor operation and monitors all main functions. Monitors operating hours, time under load, % load, number of starts/hour. The controller menu includes a fault log, maintenance log, and the ATMOS Care function — electronic protection against a clogged separator. Remote communication via MODBUS/RTU. Up to 3 daily schedules for each day of the week. Master-Slave mode for 2 compressors.
Accessories — option: ARCHON Supervisory System
For compressor stations with 3, 5, or 9 compressors, we offer the ARCHON supervisory control system based on SIEMENS Simatic S7-1200. Up to 10 weekly schedules, 3 control methods (priority / operating hours / highest efficiency), 3 independent pressure schedules. Communication via Profinet or Modbus.
Related models and alternatives
If the SmartTronic ST 55 Vario+ FD does not exactly match your operation, consider the following alternatives:
Frequently asked questions
- What is the difference between ST 30, ST 30+, and ST 30 Vario+?
- ST 30+ is a higher performance version (higher output with the same 30 kW motor). ST 30 Vario+ adds a Danfoss VLT frequency converter — smooth performance regulation, 20–30% energy savings for variable consumption. ST 30 (without +) is not in the current price list.
- What does FD mean in the ST xx + FD version?
- FD = Fusion Dryer integrated directly into the compressor housing. Adsorption dryer utilizing waste compression heat for regeneration. Achievable pressure dew point +5 °C to -20 °C (up to -40 °C with additional equipment). Energy savings compared to a standalone dryer.
- What is the difference between the A150 block and the SCA-14/SCA-20? The A150 is an ATMOS 5th generation block with an N-profile rotor, developed with London City University – it is used in ST 30-55 kW models. SCA-14-G-R and SCA-20-G-R are blocks for higher outputs of 75-110 kW (larger rotors, higher displacement). All three blocks are oil-lubricated with high efficiency.
- Can I choose a different working pressure than 7.5 bar?
- Yes. The SmartTronic is available in 4 pressure variants: 7.5 / 8.5 / 10 / 13 bar (selected at production). At higher pressures, the displacement decreases in m³/min. For higher pressures of 14-25 bar, please inquire – ATMOS also supplies special variants.
- How does remote management ATMOS Plus work? ATMOS Plus is a cloud application for remote monitoring of compressors. Using a communication unit, the compressor connects to the internet (Profinet / Modbus). You can monitor pressure, operating hours, temperatures, and service intervals. It is possible to remotely set pressures and alarms.
- Included free with SmartTronic.
- What is 72% heat recovery and how is it suitable for production? The compressor produces heat (94% of the input electrical energy) during air compression. The ATMOS heat recovery exchanger captures this heat from the oil circuit and transfers it to the water circuit (heating, hot water preparation). Up to 72% of the input electrical energy is usable again.
- Investment payback typically within 1 year.
- What is ARCHON and when is it suitable? ARCHON is a master control system based on Siemens Simatic S7-1200 for coordinating 3, 5, or 9 compressors as a single source. Up to 10 weekly schedules, 3 control methods (priorities / operating hours / highest efficiency). Profinet / Modbus communication. It is suitable for central compressor stations with multiple units.
Additional parameters
| Category: | SMARTRONIC |
|---|---|
| Warranty: | 7 let |
| Version: | Screw compressor |
| Pressure: | 13 bar |
| Displacement: | 8 900 l/min |
| Pressure vessel volume: | bez nádoby |
| Connecting: | 1 1/4" |
| Motor power: | 55 kW |
| Mains voltage: | 400/50 V/Hz |
| Lubrication: | Oleic |
| Noise: | 71 dB(A) |
| Engine: | Electric |
| Soundproofed: | Yes |
| Drive: | Direct |
| Air dryer: | Yes |
| Retrieved from: | Professional |
| Development: | Stationary |
| Frequency converter: | Yes |
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A domestic company of world quality
One of the leading companies operating in the field of compressed air not only in the Czech Republic, but also in the world, is the domestic manufacturer ATMOS Chrást s.r.o., which presents itself mainly by the production of screw and piston compressors, screw blocks and motor generators. The roots of the company go back to 1899, when foundries and machine shops were established in the West Bohemian village; during the communist regime, the machine shops belonged to the national company Škoda Plzeň. It was at the end of this era that the company began licensed production of screw blocks and screw compressors, which became very popular over the years due to their reliability. Since then, ATMOS has come up with more than 25 new compressor types - creating a range of mobile, locomotive or stationary compressors that are subject to the most stringent global standards, adding the hallmark of honest design that is so much a part of ATMOS even in today's consumer age.
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A product offer for everyone
ATMOS is constantly working on new compressors and the characteristics are subject to regular technological research. As a result, the company has already come up with innovative ideas on several occasions, such as when it extremely reduced the noise level of stationary compressors without losing their top performance parameters, thanks to which they have been widely exported abroad. However, in addition to large companies, ATMOS also meets the needs of private customers with smaller workshop machines. Another breakthrough was the creation of the small and compact Albert compressors, whose product range is constantly expanding and are suitable for hobby use. More than 60 of these types are currently in production, with outputs ranging from 3 to 22 kW. The company is the youngest to launch motor generators, filling one of the gaps in the domestic market.
An overview of the compressors offered by ATMOS at Air Compressors can be found below.