EMI Filters

EMI Filters – Your Shield Against Electromagnetic Interference

At PurityElec, we engineer high-performance EMI filters designed to eliminate unwanted electromagnetic interference and radio frequency noise from AC and DC power lines. Our filters ensure smooth, compliant, and interference-free operation for sensitive electronics in industrial, commercial, and defense applications.
Whether you need single-phase, three-phase, or custom EMI solutions, PurityElec's EMI Filters deliver exceptional performance, durability, and reliability
emifilter

Key Features

• Broad Frequency Attenuation – Suppresses both common-mode and differential-mode noise.
• High Performance – Stable filtering across a wide frequency range (150kHz – 30MHz).
• Rugged Construction – Built to withstand harsh industrial and environmental conditions.
• Wide Voltage & Current Range – From compact filters for small electronics to heavy-duty models for industrial equipment.
• Global Compliance – Meets EMC regulations including CE, RoHS, REACH.

Applications

• Industrial automation & control systems
• Renewable energy inverters & battery storage
• Medical devices & laboratory equipment
• Telecommunications & data centers
• Railway, aerospace, and defense electronics
• Household appliances and consumer electronics

Technical Specifications
Voltage Rating Up to 1000V AC/DC
Current Ratings 1A – 600A
Attenuation ≥ 60dB (150kHz – 30MHz)
Operating Temperature –40°C to +85°C
Compliance CE, UL, RoHS, REACH

Why PurityElec?

Our EMI suppression expertise ensures you get the perfect filter for your application — from off-the-shelf units to fully custom solutions. Choosing PurityElec means:
✔ EMC compliance made simple
✔ Extended equipment life through cleaner power
✔ Reduced downtime with reliable performance

Frequently Asked Questions

  • Q1. What is an EMI Filter?
    An EMI (Electromagnetic Interference) Filter is a device that reduces unwanted electromagnetic noise in electrical systems to protect equipment, improve power quality, and ensure compliance with EMC regulations.
  • Q2. Why are EMI filters important?
    • • Prevents malfunction of sensitive electronic equipment
    • • Reduces electromagnetic noise in power lines
    • • Ensures compliance with international EMC standards
    • • Improves overall system reliability and lifespan of devices
  • Q3. Who requires EMI filters?
    • • Industrial automation systems and machinery
    • • Data centers, servers, and IT equipment
    • • Medical devices and hospital equipment
    • • Power electronics (inverters, drives, UPS)
    • • Consumer electronics and renewable energy systems
  • Q4. How does an EMI filter work?
    EMI filters use capacitors, inductors, and sometimes ferrite cores to block high-frequency noise while allowing the desired power frequency to pass.
  • Q5. What types of EMI filters are there?
    • • Differential Mode (DM) filters: Suppress noise between line and neutral
    • • Common Mode (CM) filters: Suppress noise between line/neutral and ground
    • • Hybrid filters: Combine DM and CM suppression
  • Q6. Can EMI filters remove harmonics?
    EMI filters are mainly designed for high-frequency noise (kHz–MHz range). They do not significantly remove low-order harmonics (50/60 Hz); harmonic filters or active harmonic filters are required for that.
  • Q7. Where are EMI filters typically installed?
    • • At the input of variable frequency drives (VFDs)
    • • Before UPS systems and power supplies
    • • In industrial automation panels
    • • On medical and sensitive electronic equipment
    • • Renewable energy inverters and chargers
  • Q8. Can EMI filters protect equipment from surges or spikes?
    EMI filters mainly suppress high-frequency noise. For surges and spikes, surge protection devices (SPD) are used alongside EMI filters.
  • Q9. Are EMI filters suitable for both AC and DC systems?
    Yes. EMI filters can be designed for AC mains as well as DC buses in power electronics systems.
  • Q10. Which standards govern EMI filter design?
    • • IEC 61000 series (Electromagnetic Compatibility)
    • • CISPR 11 / 22 / 32 (Industrial and consumer EMC standards)
    • • Local utility and equipment EMC regulations
  • Q11. How do we know if an EMI filter is needed?
    • • Equipment experiences malfunctions due to electromagnetic noise
    • • EMC compliance testing fails
    • • High-frequency noise is observed on power lines or sensitive circuits
    • • Preventing interference with other nearby equipment
  • Q12. What are the key benefits of EMI filters?
    • • Protects sensitive equipment from electromagnetic noise
    • • Ensures compliance with EMC regulations
    • • Improves reliability and lifespan of devices
    • • Reduces interference in nearby communication or electronic systems
  • Q13. What are the limitations of EMI filters?
    • • Only effective for high-frequency noise, not low-order harmonics
    • • Requires proper sizing for voltage, current, and frequency range
    • • May add minor voltage drop or power loss if undersized or poorly designed