EPA Filters

Harmonic filters enhance power quality and protect electrical loads from adverse effects by mitigating harmonic distortion at the input stage of variable frequency drives (VFDs). These filters serve several vital purposes:

• Filtering Out Harmonics: By removing unwanted harmonic frequencies, these filters preserve the integrity of the power supply and provide a clean sinusoidal waveform.
• Maintaining Power Quality: Reducing harmonic distortion helps maintain the power quality in the electrical system, preventing interference, overheating, and potential equipment failures.
• Compliance with Standards: Harmonic filters allow systems to comply with standards like IEEE519-2014, which specify permissible levels of harmonic content to ensure safety and compatibility in industrial settings.
• Enhancing Efficiency and Reliability: By alleviating harmonic effects, these filters boost the efficiency and reliability of electrical equipment, thereby extending their operational lifespan and stability.

Line reactors are electromagnetic inductors that protect VFDs and motor control devices from voltage surges, spikes, and transients. Line reactors are installed between the VFD and the power source, while load reactors are installed between the VFD and the motor. Line reactors and load reactors limit current flow, electrical noise, and harmonic distortion to enhance power quality. Thus, line reactors and load reactors improve the stability and efficiency of the motor system.

EPA GmbH offers a range of line reactors designed to increase power quality. The following products are ideal for electrical systems that require interference immunity and harmonic limitation:

• EPA1N (Single Phase, uk 8%) : Available from 7A to 32A, EPA1N minimizes harmonics, improves interference immunity, and decreases voltage drops/current peaks in unchoked systems and line-operating motors.
• EPA2N (Three Phase, uk 2%) : Available from 7A to 400A, EPA2N offers similar benefits as EPA1N but is designed for three-phase supplies.
• EPA3N (Three Phase, uk 4%) : Available from 2A to 1100A, EPA3N has similar features as EPA2N but supports a wider range of current ratings.

Sinusoidal or sine-wave filters convert the pulse width modulated (PWM) outputs from VFDs or inverters into near-perfect sine waves. As a result, sinusoidal filters smooth the rapid switching signals that can cause electromagnetic interference (EMI). They also protect motors and cable insulation from damage by getting rid of high voltage spikes.

EPA GmbH’s sinusoidal filters SFAF2-400 and SFAF2-500 are designed for systems with long motor cables. These filters cover current ranges from 2A to 1200A and voltages of 400V, 500V, and 690V. The sine-wave filters reduce motor noise, decrease leakage currents and voltage spikes, protect bearings and windings, and enhance electromagnetic compatibility with UL-approved insulation.

RFI filters manage radiofrequency interference (RFI) by blocking unwanted internal and external RF signals that can disrupt electronic devices. By containing passive components and blocking radiated and conducted RFI, RFI filters selectively reject interference frequencies within power lines or signals.

RFI filters from EPA include the following:

• Single-Phase Filters: Single-phase filters are available in 115V or 230V AC voltage and rated currents from 1A to 55A. Compact, universal models have DIN rail options and specialized filters for electrical drives. For specialized applications, select single-phase RFI filters offer surge voltage protection and earth-line chokes.
• Three-Phase Filters: Three-phase RFI filters are available in 400V to 690V AC voltage and currents from 4A to 2500A. Compact DIN rail models are rated at 5-50A for smaller installations. Universal, compact, and high-performance models are rated 7-180A, with options for high attenuation and low leakage. High current, specialized models are rated from 300-1600A for high-emission applications.
• Three-Phase Filters (with Neutral) : EPA’s three-phase filters with neutral have voltages from 400V to 520V AC and rated currents from 6A to 1000A. The NF-4-BFG model is rated for 10-50A and is compact for DIN rails. The NF-4 Series is a high-performance, low-leakage model rated for 6-1000A and designed for industrial applications. These models are also available in compact housing.