MZB-15A Screw Compressor – 11 kW, Direct Drive, No Inverter

1. Purpose and Operating Principle

How it works: the electric motor turns the screw airend rotors directly through a flexible coupling; air is compressed in the presence of oil, passes through the oil separator, and is delivered to the user through the G3/4 outlet. Pressure is maintained by “load — unload” control without changing motor speed (version without a variable frequency drive).

The compressor is supplied without an air receiver and without a dryer — this lets you choose the receiver volume and air treatment system to match your consumption and air quality requirements. If you need a ready-made station, see the MZB 15A-400 with a 400 L receiver and dryer.

2. Technical Specifications

⚠️ Needs confirmation: the product page lists dimensions of 1080 × 750 × 1000 mm, while the manufacturer’s catalog for the MZB-15A shows 950 × 750 × 1250 mm. Before planning the installation space, confirm the actual dimensions with our manager.

Output flow rate by working pressure:

3. Design Features

1. Direct drive instead of belts. Torque is transmitted from the motor to the airend through a flexible coupling: no slippage losses, no belt tension to monitor or belts to replace, and the motor and airend bearings carry no radial load from a tensioned belt.
2. Long-life screw airend. The screw design is more efficient than a piston design in prolonged operation and is built for continuous duty. The MZB-A line uses BAOSI airends ⚠️ (confirm the airend brand for this version with our manager).
3. Energy-efficient IP55 motor, insulation class F. Stated energy efficiency is 5% above standard, and dust/moisture protection suits workshop conditions.
4. Oil tank with immersed separator. Reduces residual oil content in the air, lowers wear, and extends maintenance intervals.
5. Reinforced cooling system. The larger-area radiator maintains stable temperature in demanding conditions.
6. Inlet valve with automatic adjustment. Air intake varies with load; the design offers high flow capacity and simple operation.
7. Multilingual controller (Russian and English). Star-delta starting, load and unload modes, automatic shutdown after prolonged lack of air demand, protections against air-oil mixture overheating, motor overload, phase sequence error, and low oil pressure; operating hours counter, reminders for oil, filter, and separator replacement, error log, and remote cloud monitoring.
8. Compact design. No special foundation is required for installation.

4. Installation Recommendations

• Power supply. Three-phase connection, 380 V / 50 Hz. Cable cross-section and circuit breaker rating should be determined by an electrician based on the motor’s rated current in the datasheet; always verify correct phase sequence — the controller blocks starting on a phase error.
• Installation location. A dry, clean, well-ventilated room; air temperature no lower than +5 °C (at lower temperatures, thickened oil makes starting and condensate separation harder). Leave free space around the unit for cooling air intake and maintenance access.
• Air receiver. The compressor is supplied without a receiver: connect it to a receiver whose volume is selected to match your air consumption profile (we’ll help you choose).
• Air treatment. For paint shops, food production, and other moisture- and oil-sensitive applications, provide a refrigerated dryer and filters after the receiver.
• Startup. Before first start, check the oil level (the system holds 18 L), the tightness of electrical and pneumatic connections, and the rotation direction; after starting, make sure there are no oil or air leaks.
• Maintenance. Follow the operating hours counter and the controller’s reminders for oil, air and oil filter, and separator replacement; intervals are set by the manufacturer’s schedule and operating conditions ⚠️ (exact intervals — ask our manager).

5. Analogues and Comparison

Comparison within the MZB-A line (direct drive, no receiver), flow rate at 10 bar:

Configuration options around this model:

• With receiver and dryer — MZB 15A-400: the same 11 kW power, a 400 L receiver, and an integrated refrigerated dryer — a complete turnkey station.
• With a variable frequency drive — inverter models in the line pay off when air demand fluctuates strongly: the motor adjusts its speed to consumption. The MZB-15A without an inverter suits sites where demand is steady and the compressor spends most of its time under load.
• With belt drive — for example, the Airpol K11 (11 kW, with a 500 L receiver): a belt drive requires tension checks and belt replacement, while direct drive does not.

When comparing with other compressors, check the output flow rate at your working pressure (not the maximum datasheet figure), the drive type and control method, whether a receiver and dryer are included, the noise level, and the availability of consumables.

6. Common Mistakes

• Choosing by power rather than by demand. Flow rate drops as pressure rises (1650 L/min at 7 bar versus 1100 L/min at 12 bar) — size the unit by flow at your working pressure.
• Operating without an air receiver. Without a receiver, the motor switches between load and unload more often and network pressure is unstable — connect a receiver of suitable volume.
• No dryer where dry air is needed. Moisture in the network causes pipe corrosion, condensate freezing in winter, and pneumatic tool failures.
• Installing in an unheated room at temperatures below +5 °C.
• Ignoring the controller’s maintenance reminders. Timely replacement of oil, filters, and separator is the key to the screw airend’s service life.
• Connecting without checking phase sequence — the controller will block starting, and bypassing the protection can damage the motor.

7. Practical Applications

A compressor delivering 1.3–1.5 m³/min (10–8 bar) at 11 kW is an optimal solution for small and medium-sized businesses and larger workshops:

• Auto repair shops and tire fitting — impact wrenches, ratchets, grinders, tire inflation, blow-off, spray guns.
• Woodworking and furniture manufacturing — nailers and staplers, pneumatic actuators and clamps on machines, edge processing, sanding and varnish preparation.
• Mechanical engineering and metalworking — assembly lines and conveyors with pneumatic cylinders, CNC machines, small to medium sandblasting guns.
• Plastics and packaging production — blow molding of small and medium PET containers, packaging lines and machines.
• Paint shops — spray guns and pneumatic sanding (with dryer and filters).
• Construction (workshop tasks) — blow-off and cleaning, plastering stations where pressure and flow requirements are met.
• Food and pharmaceutical industries — process control, with additional air purification and drying systems installed.

8. Expert Opinion

Vitali Boluchevski, Lead Engineer at Acvatron SRL (18 years of experience):

“The MZB-15A is a ‘golden mean’ for businesses moving from piston compressors to continuous production: 11 kW and direct drive deliver a stable airflow without belt hassles. The no-inverter version is a deliberate choice for those whose compressor spends most of its time under load: it’s simpler and cheaper to maintain. What I advise customers is not to buy a compressor ‘separately from the system’: decide on the receiver, dryer, and filters for your application in advance. This is especially important for paint shops and food production — moisture and oil in the air cancel out any savings on equipment. And, of course, don’t skip maintenance: the controller itself will remind you when to replace the oil, filters, and separator.”

9. Frequently Asked Questions

1. What flow rate does the MZB-15A deliver? It depends on working pressure: 1650 L/min at 7 bar, 1500 L/min at 8 bar, 1300 L/min at 10 bar, and 1100 L/min at 12 bar.

2. Are an air receiver and dryer included? No, the compressor is supplied without a receiver and without a dryer — they are chosen to match your consumption and air quality requirements. The ready-made solution with a 400 L receiver and dryer is the MZB 15A-400.

3. What power supply is needed for connection? Three-phase, 380 V, 50 Hz. Starting is star–delta; the controller monitors phase sequence and blocks starting on an error.

4. Can the compressor run without stopping? Yes, the unit is designed for continuous operation 24/7 or in 2–3 shifts, provided the maintenance schedule is followed.

5. How does the no-inverter version differ from the variable frequency drive version? Without an inverter, the motor runs at constant speed and pressure is maintained by switching between load and unload. An inverter smoothly adjusts speed to air demand and pays off when consumption varies a lot; with steady, near-maximum demand, the no-inverter version is simpler and cheaper.

6. How much oil needs to be filled? The system holds 18 liters. Choose the oil brand and viscosity according to the manufacturer’s schedule — we can help you select.

7. Is the compressor suitable for car painting? Yes, provided a receiver, refrigerated dryer, and air purification filters are installed after the compressor — moisture and oil in the air are unacceptable when applying paint and coatings.

8. What is the noise level? 68 ± 2 dB — considerably quieter than piston equivalents; the unit can be placed close to the points of use.