B35 series automatic capacitor banks

B35 series THDi ≤ 35%

Industrial plants where the load varies greatly throughout normal operation will require automatic P.F. equipment in order to connect the necessary capacitive power. 

More details

Technical characteristics

  • Rated voltage: 400Vac
  • Rated frequency: 50Hz (60Hz on request)
  • Voltage of auxiliary circuits: 110Vac
  • Working temperature range: -10°C/+50°C
  • Cubicle: 20/10mm sheet steel, protected against corrosion by a phosphating treatment. Epoxy powder painted, RAL 7035 color (other colors on request) External Protection Degree: IP30 (type S-M), IP40 (Type L) Locking system: by screw for cubicle type S and type M by key for cubicle type L
  • Ventilation: Forced
  • Isolating switch: Three-pole with door interlocking device
  • Supply: Type S: entry of the cable from the top/bottom Type M: entry of the cable from the top Type L: entry of the cable from the bottom
  • Wiring: By N07VK CEI 20-22 flame retardant cables. Auxiliary circuits are identified as in the electrical drawing
  • Contactors: Each bank of capacitors is controlled by a three-pole contactor. To limit the overcurrent peaks , each contactor is provided with insertion resistors. Rated voltage of auxiliary circuits: 110 Vac, 50 Hz.
  • Fuses: Each bank of capacitors is protected by a set of three fuses (NH00 type) with high breaking capacity. Also the auxiliary circuits are protected by fuses.
  • Capacitors B35 500 Vac Series Single phase of type self-healing, made up of metalized polypropylene, equipped with overpressure safety device and discharge resistor. Filling: biodegradable non toxic dry type, PCB free. Manufactured using new technologies of metallization. Delta connection. Capacitance tolerance: -5% +10% Dielectric losses: <0.3W/kvar Temperature class: -25°C (55°C)
  • Regulators: Varmetric measurement by means of a C.T. (Current Transformer) (secondary 5A) not supplied
  • Reference Standards: Comply with L.V. 73/23 (93/68) EEC Directive Capacitors: CEI EN 60831-1/2 Equipment: CEI EN 60439-1, CEI EN 61921-1
  • Options (on request): Automatic switch Isolator with fuses Protection degree : IP55 Type M: entry of the cable from bottom Type L: entry of the cable from the top

Power Factor Correction in presence of harmonics

In recent years, Power Factor Correction has evolved greatly due to the presence of generated harmonics by the loads. These loads produce harmonic currents and voltage which distorts the network waveforms. The main sources of harmonics are generated by AC/DC static converters and UPS systems. For these reasons it is essential that any installation of Power Factor Correction equipment must be carefully evaluated. The possible presence of harmonic currents in the network could create conditions of parallel resonance between the inductance of the network and the capacitors, generating overcurrents and overvoltages, which would cause premature failure of the power factor correction capacitors. The ideal power factor correction solution for any system must be determined by examination of the system parameters and harmonic spectrum.

Power factor correction

Level of current harmonic distortion allowed in the equipment

THDiC % on the capacitorsTHDIi % on the networkCapacitor banks
≤ 25≤ 10*B25PF/R
≤ 35≤ 15*B35PF/S
≤ 50  ≤ 20*B50PF/XS
≤ 85≤ 50**AR180PF/A
≤ 100  ≤ 100**AR140PF/HA

The new RAUNI regulators are equipped with alarm threshold, which disconnects the equipment if the ALARM THDi is exceeded. Equipments with blocking inductance have this threshold detection disconnected because there is no resonance risk. * Resonance not allowed ** THDv max 6%

Network: 400Vac 50Hz THDi ≤15%.

Resonance non allowed

Capacitors: 500Vac 50Hz, THDi ≤35%


WxDxH, mm


kVAR at


Power of banks kVAR












kVAR at


B35PFSS-10.5 460x215x48010,51,5-3-6763RAUNI96151211
B35PFSS-15 460x215x480153-6-6563RAUNI96211316
B35PFSS-21 460x215x480213-6-12763RAUNI96301422
B35PFSS-24 460x215x480246-6-12463RAUNI96341525
B35PFSS-28.5 610x215x48028,51,5-3-6-6-121980RAUNI96412230
B35PFSS-30 460x215x480306-12-125100RAUNI96431632
B35PFSS-36 610x215x480366-6-12-126100RAUNI96522338
B35PFSS-42 610x215x480426-12-12-127100RAUNI96602445
B35PFSS-48 610x215x480486-6-12-248100RAUNI96692751
B35PFSS-54 610x215x480546-12-12-249125RAUNI96782958
B35PFSS-60 610x215x4806012-12-12-245160RAUNI96863165
B35PFMS-84 420x380x920846-12-18-24-2414250RAUNI961214791
B35PFMS-102 420x380x9201026-12-18-24-4217400RAUNI9614751110
B35PFMS-120 420x380x92012012-24-36-4810400RAUNI9617354130
B35PFMS-144 420x380x114014412-24-48-6012400RAUNI9620760155
B35PFMS-156 420x380x114015612-24-48-7213400RAUNI9622565168
B35PFMS-180 420x380x114018012-24-42-9615400RAUNI9625969194
B35PFMS-204 420x380x136020424-48-48-848500RAUNI9629474220
B35PFLS-240 610x610x176024024-24-48-48-48-8410630RAUNI144345260258
B35PFLS-300 610x610x176030030-30-60-60-60-6010800RAUNI144432280322
B35PFLS-360 610x610x176036036-36-72-72-72-7210800RAUNI144518300388
B35PFLS-420 610x610x196042042-42-84-84-84-84101250RAUNI144605320452
B35PFLS-480 610x610x196048048-48-96-96-96-96101250RAUNI144691340517
B35PFLS-540 610x610x216054054-54-108-108-108-108101250RAUNI144777380582
B35PFLS-600 1220x610x176060060-60-120-120-120-120102x800RAUNI144864552646
B35PFLS-660 1220x610x176066066-66-132-132-132-132102x800RAUNI144950574711
B35PFLS-720 1220x610x176072072-72-144-144-144-144102x800RAUNI1441036600775
B35PFLS-780 1220x610x196078078-78-156-156-156-156102x1250RAUNI1441123620840
B35PFLS-840 1220x610x196084084-84-168-168-168-168102x1250RAUNI1441209640904
B35PFLS-900 1220x610x196090090-90-180-180-180-180102x1250RAUNI1441296660969
B35PFLS-960 1220x610x196096096-96-192-192-192-192102x1250RAUNI14413826801033
B35PFLS-1020 1220x610x21601020102-102-204-204-204-204102x1250RAUNI14414687001098
B35PFLS-1080 1220x610x21601080108-108-216-216-216-216102x1250RAUNI14415557201163