Water and wastewater
treatment

Improve electrical reliability in water and wastewater treatment plants with advanced harmonic mitigation. Merus® A2 Active Harmonic Filters reduce harmonic distortion from VFD-controlled pumps and aeration blowers, helping prevent electrical disturbances and meet power quality requirements.

Reliable water treatment starts with power quality

Water and wastewater treatment plants rely on Variable Frequency Drives (VFDs) to control pumps, aeration blowers, and other essential equipment. While VFDs improve process control and energy efficiency, they also generate harmonic currents that can affect the electrical network.

Without proper harmonic mitigation, these disturbances can lead to pump trips, equipment overheating, increased electrical losses and interruptions to critical treatment processes.

Did you know? Aeration is often the largest electricity consumer in wastewater treatment plants. Variable-speed blowers help optimize energy consumption, but their VFDs also introduce harmonic distortion that needs to be managed.

Common power quality challenges in water and wastewater treatment

Water and wastewater facilities operate under changing loads and demanding conditions. Electrical disturbances can affect individual equipment or compromise the reliability of entire treatment processes.

Unexpected pump and blower trips → Harmonics can cause nuisance tripping and process interruptions.
Equipment overheating → Harmonic currents increase heating in transformers and cables.
Higher maintenance costs → Electrical stress accelerates equipment aging.
Reduced electrical system efficiency → Harmonics increase losses and reduce available capacity.
Power quality compliance challenges → Excessive harmonics can exceed IEEE 519 and local network limits.
Changing electrical loads → Varying pump and blower speeds affect harmonic levels.

Where harmonics occur in water and wastewater treatment

Influent and lift station pumps → VFDs regulate wastewater flow and generate harmonic currents.
Aeration blowers → VFDs control oxygen supply during biological treatment.
Sludge handling systems → VFD-controlled sludge pumps and dewatering equipment contribute to harmonic loading.
Water intake and distribution pumps → High-capacity drives introduce harmonics into electrical distribution systems.
Electrical distribution → Harmonic currents from multiple drives affect transformers, cables and switchgear.

Tailored power quality solutions for water and wastewater facilities

Every water and wastewater treatment installation has different electrical requirements. The number of pumps, VFD capacities, operating conditions and applicable harmonic limits all influence the design of the electrical system.

Merus^® A2 Active Harmonic Filters provide flexible harmonic mitigation for both new projects and existing facilities. Their modular design allows compensation capacity to be adapted to the installation, while dynamic filtering responds to changes in electrical loads.

Quick summary

⚡ Challenge

VFD-controlled pumps and aeration blowers generate harmonic distortion that can disrupt treatment processes, increase electrical losses, and create compliance challenges.

🛡️ Solution

Merus^® A2 Active Harmonic Filters dynamically compensate harmonics from multiple VFDs, helping maintain reliable electrical operation as pumping and treatment loads change.

📈 Key benefits

Reduce pump and blower trips related to harmonic distortion
Support reliable treatment processes
Meet applicable harmonic limits
Reduce electrical losses
Protect transformers and electrical equipment

🏢 Applications

Wastewater treatment plants
Drinking water treatment plants
Pumping and lift stations
Sludge treatment facilities
Desalination plants

🗣️ Let’s talk!

We offer a comprehensive analysis of your power quality needs and provide tailored compensation solutions to seamlessly integrate into your system.

Power quality measurement

Planning a new pumping installation or experiencing harmonic distortion in an existing treatment plant? Our experts can help identify the source and find the right harmonic mitigation solution.

Viktoria Mansikkala

Sales Manager, Active Harmonic Filter
Partners, Europe

+358 44 9 735 737 viktoria.mansikkala@meruspower.com

Why is Merus^® A2 the smart choice?

Optimize your investment → Optimize your investment → Cost-effective harmonic mitigation for multiple VFD-driven pumps and blowers. Read more
Designed for flexibility → Centralized or decentralized filtering for pumping and treatment systems.
Dynamic performance → Real-time harmonic mitigation as pump and blower loads change.
Ready for any project → Suitable for new and existing water and wastewater treatment facilities.
Certified for confidence → UL508 & CSA C22.2-listed and CE-marked modules.
Built to grow → Modular, scalable design for plant expansions and upgrades.
Beyond harmonic filtering → Reactive power compensation and load balancing for improved electrical performance.

Merus^® A2 Active Harmonic Filters continuously monitor harmonic currents and inject equal but opposite currents to cancel harmonic distortion, much like noise-canceling headphones eliminate unwanted sound. Unlike passive solutions, active harmonic filters respond dynamically to changing loads. In addition to harmonic mitigation, they compensate reactive power and help balance electrical currents, improving overall system stability and power factor.

Merus^® A2
Active Harmonic Filter

A scalable, versatile, and durable active harmonic filtering solution designed and manufactured in Finland using innovative Merus^® Technology.

Power quality beyond water treatment: Water-based cooling systems

Water also plays an important role in cooling systems used in data centers, industrial facilities and commercial buildings. Cooling water pumps, chilled-water systems and cooling towers often rely on VFD-controlled equipment to optimize energy consumption and respond to changing cooling demands.

Like pumps and blowers in water treatment facilities, these systems can generate harmonic distortion that affects electrical performance and reliability. Merus Power provides active harmonic filtering solutions for water-based cooling applications, helping maintain reliable operation in facilities where cooling is essential.