Atlas Copco ZR 75 VSD (FF) Oil-Free Rotary Screw Air Compressor

Description

The Atlas Copco ZR 75 VSD is the water-cooled variable speed drive machine of the ZR/ZT 55-90 oil-free family, rated at 75 kW of installed motor power and regulated continuously between 30 and 100 percent of its maximum capacity. The compression chambers run completely free of oil, and the package carries the ISO 8573-1 CLASS 0 (2010) certification verified by TÜV.

The integrated drive adjusts the motor speed to the air demand of the plant in real time, so the ZR 75 VSD delivers energy savings of up to 35 percent where the consumption profile fluctuates. Two pressure versions at 8.6 and 10.4 bar(e) cover free air delivery from 74 to 259 l/s at maximum working pressure, and the water-cooled circuit opens the full heat recovery potential of the platform.

Where the ZR 75 VSD Sits in the Oil-Free Range

The ZR/ZT 55-90 family serves the plants whose oil-free demand has outgrown the smaller packages but has not yet reached the ZR/ZT 110-275 class. Within the family, the ZR 75 VSD shares its rating with the fixed-speed ZR 75 and the air-cooled ZT 75 VSD, and 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.

Atlas Copco pioneered Variable Speed Drive technology in the compressed air industry and pioneered oil-free air over sixty years, becoming the first manufacturer awarded CLASS 0 certification. The ZR 75 VSD combines both lines in one package: an all-in-one installation that places on a flat floor, connects to the power line, the cooling water circuit and the air outlet, and starts with the push of a button.

Two Branches, One Platform

Two names describe the branches of the ZR 75 VSD, and each adds one fact:

• Standard — the compressor package delivers oil-free air for networks with external air treatment downstream, with the water-cooled design rejecting the heat of compression into the cooling water circuit.
• 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 working pressure of the Full Feature variant is confirmed with Atlas Copco for the specific order. The ZR 75 VSD carries both branches on one platform, so a plant can start with the Standard build and move to the Full Feature dryer without changing the machine room layout. Plants that run a steady load instead of a swinging profile pick the fixed-speed ZR 75 of the same rating.

How the Integrated VSD Works

Over 80 percent of the lifecycle cost of a compressor is taken up by the energy it consumes, and the generation of compressed air can account for more than 40 percent of the total electricity bill of a plant. The ZR 75 VSD attacks that share directly: the drive closely follows the air demand by automatically adjusting the motor speed, which results in energy savings of up to 35 percent.

What Is Unique About the Integrated Design

The integrated design differs from a bolt-on drive in several ways, and each one protects the performance of the package:

• The Elektronikon controller runs both the compressor and the integrated converter, ensuring maximum machine safety within parameters.
• Flexible pressure selection from 4 to 10.4 bar(e) reduces electricity use at the actual pressure the process needs.
• The converter and motor are designed as one unit, with protected bearings for the highest efficiency across the speed range.
• The electric motor is specifically designed for low operating speeds, with clear attention to motor cooling and compressor cooling requirements.
• All VSD compressors are EMC tested and certified, so compressor operation does not influence external sources and vice versa.
• Mechanical enhancements ensure that all components operate below critical vibration levels throughout the entire speed range.
• A highly efficient frequency converter sits in its own cubicle inside the package.

Full regulation between 30 and 100 percent of the maximum capacity eliminates the unload losses of a fixed-speed machine, and no compressed air is blown off to the atmosphere. The Life Cycle Cost of the installation drops by an average of 22 percent, and a lowered system pressure band trims the energy use across the production further. For a plant whose demand never stands still, the ZR 75 VSD turns those figures into a lower electricity bill from the first month of operation.

Technical Specifications of the ZR 75 VSD

The table below condenses the ZR 75 VSD into its headline figures:

Rated Data by Pressure Variant

Unit performance is measured according to ISO 1217, annex C, edition 4 (2009), and for VSD machines the free air delivery is measured at the maximum working pressure of each variant. The 8.6 bar(e) version spans the wide working band from 4 bar upward:

The 10.4 bar(e) version shifts the same regulation range up one band for processes that need the higher network pressure:

The sound pressure level reads 74 dB(A) at the work station on both variants, two decibels below the air-cooled ZT 75 VSD. The value is the A-weighted emission sound pressure level measured according to ISO 2151: 2004 using the ISO 9614/2 method, with a total uncertainty value of 3 dB(A).

Rated Data of the VSD+ Build

The VSD+ build extends the ZR 75 VSD in the 10.4 bar class with dual NEOS drives and a permanent magnet motor. The dual drive system regulates the machine from 28 to 100 percent of load without unloaded operation, and the unit performance follows the same ISO 1217 measurement basis:

The sound pressure level of the VSD+ build reads 66 dB(A) at the work station. In the Full Feature build with the integrated dryer, the rated data reads 79 to 243 l/s (167 to 514 cfm) at the minimum setting, 79 to 230 l/s at 7 bar, 79 to 204 l/s at 9 bar and 78 to 185 l/s (164 to 392 cfm) at 10.4 bar, with the same sound level of 66 dB(A).

The ZR branch adds a 13 bar VSD+ variant for high-pressure networks. From the minimum setting of 9 bar(e) it delivers 78.5 to 185.6 l/s (166.3 to 393.3 cfm), at the effective setting of 10.4 bar(e) it delivers 77.2 to 184.5 l/s, and at the maximum of 13 bar(e) it still delivers 75.6 to 148.6 l/s (160.2 to 314.8 cfm) at 67 dB(A).

Dimensions and Weight

The ZR 75 VSD keeps one footprint across both branches, and the water-cooled design leaves the heat rejection to the cooling water circuit:

Both branches measure 2,180 mm in length, and no foundations are required for either one. The package installs directly on the flat floor of the compressor room, with the cooling water connections at the rear of the frame.

Class 0 Air Purity, Verified by TÜV

The ZR 75 VSD 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 ZR 75 VSD the default choice where a single trace of oil spoils 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.

Water Cooling and Heat Recovery

Water cooling defines the ZR branch of the family. The closed heat exchange path keeps the sound pressure level of the ZR 75 VSD two decibels below the air-cooled sibling and holds the package stable in hot machine rooms, because the cooling water carries the heat of compression out of the frame instead of the room air.

That recovered heat is an asset: the water-cooled design turns the compression heat into a source for process water, washing water or space heating, which raises the total energy efficiency of the site again.

Full Feature: The Integrated IMD Adsorption Dryer

In the ZR 75 VSD 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, 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 converter from one control system, which is the first pillar of the integrated VSD design of the ZR 75 VSD. 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 ZR 75 VSD 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 ZR 75 VSD

Food and beverage plants run the ZR 75 VSD 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 ZR 75 VSD ability to run around the clock in extreme temperatures and humidity conditions.

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. Networks with several compressors add the ZR 75 VSD next to a fixed-speed base machine, and plants that need the larger frame step up to the ZR 90 VSD of the same platform.

Service and Support Around the ZR 75 VSD

The ZR 75 VSD 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 ZR 75 VSD and its Full Feature branch, and the parts coverage follows the same platform index as the fixed-speed ZR 75 and the larger ZR 90 VSD. 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 ZR 75 VSD deliver at 8.6 bar?

At the 8.6 bar(e) maximum working point the version delivers between 74 and 201 l/s, which equals 4.4 to 12.1 m³/min or 157 to 426 cfm, measured at the maximum working pressure according to ISO 1217 annex C, edition 4 (2009).

How much energy does the VSD save?

The drive adjusts the motor speed to the air demand, which results in energy savings of up to 35 percent, and the Life Cycle Cost of the installation drops by an average of 22 percent. Regulation runs continuously between 30 and 100 percent of the maximum capacity without unload losses or blow-off. The VSD+ build of the platform adds dual NEOS drives that regulate the machine from 28 to 100 percent of load.

Is the ZR 75 VSD water-cooled?

Yes. The ZR letter marks the water-cooled branch of the ZR/ZT family: the cooling water circuit carries the heat of compression out of the frame, which holds the sound level at 74 dB(A) and enables heat recovery. The air-cooled equivalent is the ZT 75 VSD.

How oil-free is the air?

The ZR 75 VSD 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 1,925 kg to 2,170 kg while the footprint stays at 2,180 × 1,450 × 2,184 mm.

How loud is the ZR 75 VSD?

The sound pressure level at the work station reads 74 dB(A) on both pressure variants. The value follows ISO 2151: 2004 with the ISO 9614/2 method and carries a total uncertainty value of 3 dB(A).