P.F.C.

AUTOMATIC

 

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

 

WHY SHOULD POWER FACTOR BE IMPROVED? 

THE BENEFITS ARE THE FOLLOWING:

REDUCED UTILITY CHARGES

INCREASED SYSTEM CAPACITY

IMPROVED VOLTAGE

REDUCED CIRCUIT LOSSES

 

REDUCED UTILITY CHARGES

Thermal capacity considerations force the Utilities to overbuild its distribution system in order to serve a facility with low power factor. The Utilities force the customer to install capacitors for reducing the reactive energy.

INCREASED SYSTEM CAPACITY

The thermal capacity of generators, transformers and cables limit the kVA that can be supplied by the system. Reducing the KVAR demand from existing load by installing capacitors, allows additional load to be added to the system.

IMPROVED VOLTAGE

High demand of reactive power increases the voltage drops across transformers, cables and other system components. The result is a decreased utilization voltage.

The voltage drops can be limited by increasing the power factor.

REDUCED CIRCUIT LOSSES

Since current is reduced in direct proportion to the increase in power factor, the resistive losses, in the circuit, are inversely proportional to the power factor. The increase of power factor allows a losses reduction with substantial benefits for the system.

SPECIAL AMBIENT CONDITIONS

Standard Power Factor Correction Equipment are not suitable to be used in places where the following special conditions occur:

Quick formation of mildew

Corrosive and saline atmosphere

Presence of explosive or highly flammable materials

Vibrations

In such cases, please, contact the Technical Department of ITALFARAD.    

POWER FACTOR CORRECTION

AUTOMATIC EQUIPMENT

R

PFS/R  PFM/R  PFL/R Series

Main 400 Vac  50 Hz  THDIL ≤10% (Resonance not allowed)

Capacitors VRC 440 Vac 50 Hz THDIC ≤50% 

S

PFS/S  PFM/S  PFL/S  Series

Main 400 Vac  50 Hz  THDIL  ≤15% (Resonance not allowed)

 Capacitors VRC 500 Vac 50 Hz  THDIC ≤70%

XS

PFS/XS  PFM/XS  PFL/XS  Series

Main 400 Vac  50 Hz  THDIL ≤20% (Resonance not allowed)

Capacitors VRC 550 Vac 50 Hz  THDIC ≤85%

40HC

PFS/40HC QA-RMF/40HC

 QA-RIF/40HC QA-RGF/40HC  Series

Main 400 Vac  50 Hz  THDIL ≤20% (Resonance not allowed)
Capacitors MFHC 400 Vac 3 In 50 Hz  THDIC ≤85%

46HC

PFS/46HC QA-RMF/46HC

 QA-RIF/46HC QA-RGF/46HC  Series

Main 400 Vac  50 Hz  THDIL ≤25% (Resonance not allowed)
Capacitors MFHC 460 Vac 3 In 50 Hz  THDIC ≤90%

A

PFM/A PFL/A Series

Main 400 Vac  50 Hz  THDIL ≤50% THDVmax 6%

180 Hz Blocking reactors

Capacitors VRC 550 Vac 50 Hz  THDIC ≤85%

HA

PFM/HA PFL/HA Series

Main 400 Vac  50 Hz  THDIL ≤100% THDVmax 6%

140 Hz Blocking reactors

Capacitors VRC 550 Vac 50 Hz  THDIC ≤100%

RATED VOLTAGE

Rated voltage of Power Factor Correction Equipment is the voltage for which the equipment has been designed.

To ensure that premature failure of the equipment is eliminated, the operating voltage should not be greater than the rated voltage.

The overvoltage limits allowed are shown in the following table in accordance to CEI EN 60831-1 Standards:

 

Type

Voltage factor x Un

(r.m.s.)

Maximum duration

Observation

Power frequency

1,00

Continuous

Highest average value during any period of capacitor energization.

For energization period less than 24 h, exceptions apply.

Power frequency

1,10

8 h in every 24 h

System voltage regulation and fluctuations.

Power frequency

1,15

30 min. in every 24 h

System voltage regulation and fluctuations.

Power frequency

1,20

5 min.

Voltage rise at light load.

Power frequency

1,30

1 min.

- - -

Anyhow, the use of  P.F.C. Equipment in conditions of overvoltage causes a reduction of the life.

WORKING TEMPERATURE

Working temperature is a fundamental parameter for the safe functioning of Power Factor Correction Equipment. Consequently, it is very important to have sufficient heat dissipation inside the Power Factor Correction Equipment cubicle. Ventilation should be adequate to prevent the temperature rise exceeding the limits of the capacitor design.

The capacitors are designed in accordance to CEI EN 60831-1 Standards and the limits of temperature rise are prescribed within this document:

Symbol

Ambient Temperature

Maximum

Highest mean over any period of:

24 h

1 year

A 40C 30C 20C
B 45C 35C 25C
C 50C 40C 30C
D 55C 45C 35C

In hot weather, it is advisable that ventilation and/or air-conditioning are fitted where the Power Factor Correction Equipment is installed. Exceeding of the temperature limits prescribed could reduce the life of the  Power Factor Correction Equipment.

Choice of P.F.C. equipment in presence of non-linear loads

The ever-increasing use of static converters, rectifiers and other generators of harmonic current and voltage distortion on the supply network make it essential to carefully evaluate the installation of Power Factor Correction equipment in order not to create a resonance condition, which amplifies overcurrent and overvoltage, becoming dangerous for the capacitors and other connected loads.

The choice of the right Power Factor Correction equipment is related to the power of the non-linear loads and the power rating of the transformer.

ITALFARAD proposes a complete range of Power Factor Correction  equipment which can meet all these demands. Our experienced Technical Department is at the disposal of the customers for advising about the best possible solution.

 

ITALFARAD S.p.A.  via IV novembre, 1   40061 Minerbio   Bologna   Italy

Telefono: ++39 051 6618311   Fax: ++39 051 6605594   E-mail: italfarad@italfarad.com

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