LV-AFB™ - Low Voltage Automatic Harmonic Filters

Product Features

• Most compact low voltage automatic filter design available in the market
• Reduced installation time with single enclosure system
• Programmable digital power factor controller with control up to 16 steps
• Automatic C/K Calibration
• Multi-Ratio Split-Core Current Transformer Supplied
• Blown fuse indicating lights
• Reactive power ratings from 150 kvar to 1000 kvar at 480 and 600 volts (75 kvar to 300 kvar at 240 volts). 
• Custom control packages available
• Indoor/Outdoor Design as standard
• UL Listed as Industrial Control Panel (508A)
• Engineered to meet customer performance specifications when required

Application  

NEPSI’s LV-AFB™ are designed for low voltage systems requiring power factor correction, harmonic voltage and current attenuation, IEEE 519 compliance, reduced system capacity, and improved voltage regulation.  They are typically installed on or near service equipment to automatically correct the total plant load. On doubled-ended substations with normally open ties, or systems will multiple service entrances, multiple banks are utilized.  These banks can be inter-connected so that proper operation can occur when a tie is closed.

For further application assistance, contact the factory or one of NEPSI’s factory trained sales representatives.

Specification

NEPSI’s LV-AFB™ is designed to endure the harsh electrical and environmental conditions that are typically found in industrial process facilities.

Enclosure

NEPSI’s LV-AFB™ is housed in an enclosure with  NEMA 1 construction (NEMA 3R and 4X are available on request) that is suitably supported, constructed, and assembled so that it has the strength and rigidity necessary to meet the requirements of ANSI/IEEE C37 and UL Standards. All fastening hardware inside and out is stainless steel. To maximize corrosion resistance, the outside of the enclosure is coated with an ANSI 61 light gray enamel finish. 

The front of the enclosure is equipped with hinged doors for easy access. The doors are mounted on stainless steel hinges and are held shut with 3-point latching handles. The handles are stainless steel and are lockable.

Reactor and capacitor supports consist of welded C4 structural steel channel. Reactors are mounted adjacent to the capacitors for thermal optimization.  Fans are not required on indoor units.  Outdoor units should be equipped with fans due to solar radiation.

Capacitors
The LV-AFB™ consists of low loss, triple bushing, self-healing capacitors, with integral discharge resistors mounted in a single steel tank. The capacitors are finished with a UL listed ANSI #61 light-gray finish and meet or exceed the latest applicable ANSI and IEEE standards.

The capacitor’s are designed and chosen with the following considerations:

• Harmonic current peaks have a 100% coincidence.
• Nominal System over-voltage of 5%.
• Ambient voltage distortion equal to the limits set forth by IEEE 519.
• Adherence to IEEE/ANSI peak and RMS voltage ratings.

Discharge Resistors: Each capacitor cell incorporates discharge resistors designed to reduce capacitor voltage to 50 volts or less within one minute after removal from the circuit.

Environmental Parameters: Capacitors are designed to operate between -40°C and +46°C (-40°F to +115°F).

Reactors

NEPSI’s low voltage harmonic filters are equipped with three-phase iron-core dry-type reactors. They have Copper windings and an H220 °C insulation system. The reactor current ratings are based on the following considerations.

• The reactor core will not saturate for currents less than 250% of the fundamental current rating of the filter bank.
• Peak flux density of the core will be less than 1.2 – 1.4 Tesla assuming all harmonic current peaks are 100% coincident.

Power Factor Controller

The LV-AFB™  is controlled by a digital power controller with the following features:

• Automatic self adjustment to any capacitor step value
• Digital indication of power factor, preset parameters and specified installation data
• No-Volt release feature to immediately disconnect all capacitors in the event of a power failure.
• Facility to connect mini-printer
• Plug-in terminal connection
• Automatic elimination of defective capacitor steps, and their indication (i.e. Welded contacts, failed capacitor, etc.)
• Visual display of target power factor alarm
• Visual display of harmonic overload alarm

Protection 

NEPSI’s harmonic filters are equipped with overload and short circuit protection.  Protection features are as follows:

Fusing: Each stage is protected from harmonic overload and faults by 600 volt 200,000 AIC, UL rated, (amps interrupting current) bus mounted fuses.  Fuses are located on the line side of reactors, capacitors, and contactors.

Blown Fuse Lights:  Blown fuse lights monitor each fuse and provide external indication of a blown capacitor fuse.

Contactors

Each step of the LV-AFB™ is switched with a NEMA rated 600 Volt contactor that is UL listed for capacitor switching.  The contacts, coils, and auxiliary contacts can be changed without disturbing other components within the bank.

Warranty

• 12 month system warranty

Optional Accessories
 

Main Disconnecting Devices: (MC__) NEPSI’s automatic harmonic filters may be equipped with either a main disconnect, main fusible disconnect or a molded case circuit breaker that is externally operated through a rotary handle. 

On/Off/Auto Switches: (H) On/Off/Auto Switches may be added to NEPSI’s standard automatic filter banks to provide complete individual control of each stage.

Ammeter: (A) A three phase ammeter can be provided to show the operating current of each filter bank stage.

Voltmeters: (V) A three phase volt meter can be provided to show the system voltage.

Keyed Interlock System: (KK) A keyed interlock system can be provided that will prevent access into the filter bank until the bank has been shut down by an upstream disconnecting device.

Out of KVAR Alarm: (KA or KL)  An out of kvar alarm can be provide to give visual and/or audible indication of not having the capability to meet the target power factor.

Dust Proofing: (D) Can be provided where location require filtering over louvers.