Oil-free screw compressor SCR-90 WG 90 kW motor power, FAD 960 Nm³/h at 7 bar, water cooling, fixed speed, pressure 7 / 8 / 10 bar
Code: SCR-90/7WG-IE4 SCR-90/8WG-IE4 SCR-90/10WG-IE4 Choose variant
Product detailed description
90 kW · class 0SCR-90 WG is an oil-free screw compressor with a 90 kW motor, water-cooled and running at fixed speed. It is supplied in three pressure versions: 960 Nm³/h at seven bar, 816 at eight and 780 at ten. The air is compressed by two screw blocks in two stages and the rotors are never lubricated — so the compressed air contains no oil, not filtered out, but none at all. The outlet is DN 65, the noise level 79 dB(A). The motor has IE4 efficiency class.
What the designation SCR-90 WG means
The number in the designation is the motor power in kilowatts, the letters after it say two things. W at the start means water cooling, and without a V the machine runs at fixed speed. The heat leaves through water-to-air exchangers, not into the room. The machine is quieter and lighter than its air-cooled counterpart, but it needs a cooling water circuit. Once the pressure is reached the machine switches to idle running — the motor keeps turning the block, but no air is produced. With steady demand that does not matter; with a fluctuating one it becomes a significant part of the electricity bill.
What is inside the SCR-90 WG
Two stages, two blocks
The air passes through two screw blocks one after the other. The first stage compresses it to roughly 2 bar, an intercooler cools it down and the second stage pushes it up to the outlet pressure. The rotors are never lubricated — the first stage is carbon steel, the second stainless, both with an MoS₂ based coating. The rotor space is separated from the gearbox by a labyrinth seal and a hermetic stainless one, and the shafts run in SKF bearings.
Why a coating instead of oil
Where a lubricated machine injects oil into the block, here the friction is cut by a molybdenum disulphide coating on the rotors and on the inner wall of the housing. According to the manufacturer this markedly extends the time between overhauls — and replacing the whole block is exactly the most expensive item an oil-free machine can bring.
Three pressure versions, three order numbers
The machine is ordered in one of three pressures and it is set at the factory — it is not a switch on the panel. A higher pressure is always paid for in air: between seven and ten bar it costs 19 % of the output with exactly the same 90 kW motor. So it is worth finding out what pressure the end use really needs instead of buying a reserve blindly.
| SCR-90 WG — three pressure versions | ||||
|---|---|---|---|---|
| Pressure | Order number | FAD output | Delivery | When to choose it |
| 7 bar | SCR-90/7WG-IE4 | 960 Nm³/h | 16,000 l/min | the most air out of the same motor; enough for most compressed air systems |
| 8 bar | SCR-90/8WG-IE4 | 816 Nm³/h | 13,600 l/min | the most common pressure in industrial systems, a reserve for pressure drops |
| 10 bar | SCR-90/10WG-IE4 | 780 Nm³/h | 13,000 l/min | only when some end use really demands it |
With fixed speed the control is two-state: the machine is either producing air or running idle.
What the machine will ask of the plant
How much space it takes and how loud it is
The machine measures 2,880 × 1,960 × 2,110 mm (L × W × H) and weighs 3,300 kg, so it takes up 5.64 m² of floor. Neither the dimensions nor the weight differ between the three pressure versions. At 79 dB(A) it belongs in a separate compressor room — this is industrial machinery, not a machine to stand beside a workstation. Besides electricity it needs a cooling water connection; in return it does not heat the room and you do not have to take the heat away with ventilation. The compressed air outlet is DN 65.
What the machine consumes
For every cubic metre of air per minute the seven-bar version draws roughly 5.6 kW of rated motor power (90 kW for 16,000 l/min). At the higher pressures it is worse, because the motor power stays the same and the air output drops. It is a figure worked out from the manufacturer table, so it can be compared directly with the machine you are weighing up alongside it. At partial demand, however, the consumption does not fall nearly as much — the machine goes into idle running and the motor keeps taking energy. If your demand fluctuates, take a look at the version with a drive.
SCR9000 control
A colour seven-inch touch display or eight navigation buttons. It shows the pressure, the temperature, the energy consumption and the hours run, keeps an eye on service intervals and returns to operation by itself after a power failure. Over Modbus RS485 the SCR-90 WG can be built into network control of up to sixteen compressors — with machines this size such sets are built routinely.
Where the air from the SCR-90 WG is used
An oil-free machine is not bought for comfort, but because nothing else will do. The manufacturer names six fields — in every one of them the air touches the product, the packaging or a person.
Equipment and accessories
What the SCR-90 WG does as standard
- Oil-free class 0 air to ISO 8573-1
- Two-stage compression, two screw blocks with an intercooler
- Rotors and housing wall with an MoS₂ based coating, double stainless steel seal
- Radial and axial SKF bearings
- Cooling by water through water-to-air exchangers
- Fixed speed, inlet valve
- A choice of 7, 8 or 10 bar, outlet DN 65
- SCR9000 controller with a colour display
- Energy consumption metering, four pressure bands, weekly run scheduling
- Modbus RS485 and network control of up to sixteen compressors
- Motor with IE4 efficiency class
What can be ordered on top
- Cyclone water separator integrated into the machine
- Heat recovery — a water-to-oil exchanger for heating service water
- HOC preparation for a loss-free heat-regenerated dryer
- Vibration diagnostics — sensors watching the condition of the bearings
How it differs from neighbouring machines
Water cooling pays off where a cooling circuit is at hand and the machine runs flat out — 960 Nm³/h at seven bar, 79 dB(A), 3,300 kg. Fluctuating demand suits SCR-90 WGV with a variable-speed drive better. Without a water circuit there is the air-cooled SCR-90 G, 80 dB(A) and 3,400 kg. A smaller plant is served by SCR-75 WG with 732 Nm³/h at seven bar, a larger one by SCR-110 WG with 1,170 Nm³/h.
Ventilek advises
Fixed speed is not a shortcoming — it is cheaper, and with steady demand a drive never pays for itself. Just watch one thing: how many hours a day SCR-90 WG would spend running idle. Above roughly a third of the time it is worth costing out the version with a drive.
The FAD output is measured to ISO 1217 and is given for each of the three pressures in which the machine is supplied; figures at other frequencies are available from the manufacturer in technical data sheets on request. The noise level is given at a distance of 1 m from the machine with a tolerance of ± 3 dB(A). The air purity class is defined by ISO 8573-1.
Additional parameters
| Category: | Air compressors |
|---|---|
| Compressor type: | Screw compressor |
| Pressure: | 7 bar, 8 bar, 10 bars |
| Air delivery: | 16,000 l/min |
| Pressure vessel volume: | It isn't |
| Connecting: | DN65 |
| Motor power: | 90 kW |
| Mains voltage: | 400/50 V/Hz |
| Lubrication: | Oil-free |
| Noise: | 79 dB(A) |
| Engine: | Electric |
| Soundproofed: | Yes |
| Drive: | Direct |
| Air dryer: | No |
| Retrieved from: | Professional |
| Development: | Stationary |
| Inverter: | No |
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SCR is the compressor brand of the Chinese company Shanghai Screw Compressor Co., Ltd, a joint venture with Japan’s ANEST IWATA since 2018. We offer series from 2.2 to 280 kW: oil-free scroll and screw machines, compact workshop compressors and two-stage machines for continuous operation.
Most SCR series come with a variable speed drive as standard and a permanent magnet motor coupled directly to the airend, without belts. The machine holds pressure by adjusting its speed and does not waste energy running unloaded. Where air comes into contact with food or medicine, choose the oil-free XA and G series.
Joint venture with ANEST IWATASCR compressor series
SCR-XA — oil-free scroll
Class 0 air in smaller volumes. Two scrolls compress the air without touching, so there is no lubricant in the compression chamber.
- 2.2–29.6 kW, 200–3,520 l/min
- from 55 dB(A) on the smallest model
- Class 0 verified by TÜV Rheinland
SCR-APM Mini — for the workshop
The smallest SCR screw machine. A permanent magnet motor drives the airend directly and the inverter matches speed to demand.
- 3.6–5.8 kW, up to 690 l/min
- stand-alone, 3-in-1 or with filtration
- 7″ IT7000 touch display
SCR-APM Maxi — workshop and production
The same technology, one size up. A stand-alone machine or a package on a 270 or 500 l air receiver with dryer and filtration.
- 7.5, 11 and 15 kW
- up to 2,000 l/min at 10 bar
- 4-in-1 and 8-in-1 packages
SCR-EPM — for shift work
Direct drive and inverter from 15 kW. One machine covers 7, 8 and 10 bar and holds pressure within ±0.1 bar.
- 15–45 kW in six sizes
- up to 9,500 l/min
- SCR9000 controller with weekly schedule
SCR-G and GV — oil-free screw
Oil-free air in large volumes. Two screw stages run dry, and the machine is air- or water-cooled.
- 37–280 kW, 7, 8 and 10 bar
- Class 0 to ISO 8573-1
- GV with variable speed drive
SCR-EPM2 — heavy industry
The main machine of the compressor room. Seven sizes with a permanent magnet motor, inverter and flanged outlet.
- 55–160 kW
- up to 33,500 l/min
- cascade of up to 16 machines without a master controller
SCR-H and HPM — two-stage
For plants that never stop. Air is compressed in two stages with intercooling, so each cubic metre takes less electricity.
- 132–280 kW
- pressure up to 12.5 bar
- less than 3 ppm oil in the air
SC Oil 46 M — SCR oil
Genuine lubricant for oil-injected machines. ISO VG 46 mineral oil for SCR screw compressors.
- change every 4,000 operating hours
- 5 and 20 l canisters
- drum for several machines
Not sure how much air you need, or whether a screw or piston compressor suits you better? The compressor selection calculator helps you find a machine for what you need the air for.
Choose a compressorSCR series side by side
| Power, air delivery, pressure and lubrication | |||||
|---|---|---|---|---|---|
| Series | Power | Max. air delivery | Pressure | Lubrication | Control |
| SCR-XA | 2.2–29.6 kW | 3,520 l/min | 7–10 bar | oil-free, Class 0 | modules switched in from SCR-7XA |
| SCR-APM Mini | 3.6–5.8 kW | 690 l/min | 10 bar | oil-injected | variable speed drive |
| SCR-APM Maxi | 7.5–15 kW | 2,000 l/min | 10 bar | oil-injected | variable speed drive |
| SCR-EPM | 15–45 kW | 9,500 l/min | 7, 8 and 10 bar | oil-injected | variable speed drive |
| SCR-G / GV | 37–280 kW | 47,000 l/min | 7, 8 and 10 bar | oil-free, Class 0 | G fixed speed, GV variable speed |
| SCR-EPM2 | 55–160 kW | 33,500 l/min | 7, 8 and 10 bar | oil-injected | variable speed drive |
| SCR-H / HPM | 132–280 kW | 60,000 l/min | 7–12.5 bar | oil-injected, under 3 ppm | H fixed speed, HPM variable speed |
The maximum air delivery is that of the largest machine in the series at the lowest pressure, measured to ISO 1217. It falls as pressure rises.
How to choose an SCR compressor
1. Work out consumption
Add up the consumption of tools and machines that run at the same time, plus a margin for leaks in the pipework. Choose the compressor by litres per minute, not by kilowatts.
2. Choose the pressure
Most tools need 7 or 8 bar. Each extra bar costs about 7% more energy, so do not buy pressure “just in case”.
3. Decide on oil
Food, pharmaceuticals, electronics or paint shops need oil-free air: the XA or G series. Other plants are fine with an oil-injected machine and filtration.
4. Add a receiver and drying
An air receiver evens out peaks and drying removes water from the pipework. The APM series combine both with the compressor on one frame.
Frequently asked questions
- Who makes SCR compressors?
- Shanghai Screw Compressor Co., Ltd, founded in Shanghai in 2000. It employs more than 250 people, over 10% of them engineers, and its factory covers more than 80,000 m². Production is certified to ISO 9001, the machines carry CE marking for Europe and UL for the US market, the oil-free machines hold a Class 0 certificate, and there is an SGS efficiency certificate as well.
- What does SCR have to do with ANEST IWATA?
- In 2018 SCR formed a joint venture with Japan’s ANEST IWATA. ANEST IWATA dates back to 1926, has been listed on the Tokyo Stock Exchange since 1973 and makes compressors, vacuum equipment and coating equipment. The SCR-XA scroll compressors use ANEST IWATA airends.
- How has the SCR range developed?
- SCR has built screw compressors since 2000. It added oil-free screw machines in 2008, a series with permanent magnet motors in 2015, and magnetic bearing centrifugal compressors in 2020.
- Oil-free or oil-injected?
- In an oil-injected machine the oil is in the compression chamber, and filtration downstream only reduces what is left. There is no oil in the compression chamber of the oil-free XA and G series, so the air meets Class 0 to ISO 8573-1. The two-stage H series is oil-injected but lets less than 3 ppm of oil into the air.
- What do the letters in the model name mean?
- For example SCR-15/10APM-500FF: 15 kW, 10 bar, APM series, 500 l air receiver and FF equipment with dryer and filtration. The suffix D stands for a package with air receiver and dryer. In the G series, W means water cooling and V a variable speed drive; in the H series, HPM is the version with an inverter.
- Which oil goes into an SCR compressor?
- Oil-injected SCR screw compressors take SC Oil 46 M mineral oil, viscosity grade ISO VG 46. It is changed every 4,000 operating hours, and we sell it in 5 and 20 l canisters and in a drum. The XA scroll compressors need no oil.
Technical data are based on the manufacturer’s documentation. SCR® is a registered trademark of Shanghai Screw Compressor Co., Ltd.