Active Filters


Loads operated by electronic devices are increasingly adopted in more and more industrial and commercial applications such as: variable speed drives, rectifiers, UPS, DC power supplies, TV, energy efficiency lamps, photocopies. These loads generate waveform distorsions that become threat for and network components.

Specifically voltage and current harmonics, where the latter is the more dangerous, generate a series of problems, examples:

  • Cable overheating.
  • Undue tripping of circuit breakers.
  • Capacitor overloading and network resonance.
  • Neutral cable overload.
  • Transformer premature ageing.
  • Electronic appliances disturbance.

AF is the new generation of active harmonic filters. It reliably mitigates harmonics and compensates voltage dips as well as reactive power. The AF analizes network disturbances and provides an opposite compensation curren. In doing so, AF actively adapts to fluctuations and responds in less than half a millisecond. Its compact dimensions, simple installation and digital intelligence allow for a quick and straight forward integration in most different applications.


  • Building automation
  • Data centers
  • Machines and automation ship propulsion
  • Tunnel ventilation
  • UPS
  • Motor drives
  • Welding equipment
  • Water treatments
  • Automotive

Technical specifications

  • Rated voltage: 380V to 480V
  • Frequency: 47 to 63 Hz
  • Rated compensation current: 30 to 100A @ 40°C
  • Total harmonic current distorsion: THID: <5%
  • Compensation until al 50° harmonic
  • Responce time: <300 μS
  • Protection degree: IP20
  • Forced cooling
  • Overload capability: 2.5xIn per 10ms
  • Ambient temperature: 40°C
  • Altitude: 1000m
  • Parallel operation up to 5 AF filters
  • Communication interfaces: ethernet, RS485, ModBus
  • Digital controller with FFT
  • Current limitation: rated current
  • Standards UL508,
  • Complaince CE (LVD 2006/95/EC)
Type Dimensions
W x D x H mm
Rated phase
A rms
Rated neutral line
A rms
AF3W-30 360x590x290 30 <900 47
AF3W-50 360x590x290 50 <1300 47
AF3W-100 468x970x412 100 <2200 105
AF3W-120 468x970x412 120 <2500 105
AF4W-30 415x840x300 30 90 <950 70
AF4W-60 415x840x300 60 180 <1800 70
AF4W-100 468x1460x412 100 300 <3000 145
AF4W-120 468x1460x412 120 300 <3000 145