Automatic Power Factor Correction (APFC) Banks

Q: How many capacitor steps are recommended for my factory?

We generally design banks with 6 to 12 steps using a binary or progressive step ratio (e.g. 25 + 25 + 50 + 50 + 100 kvar). This allows fine step resolution under light loads while providing rapid bulk kvar response during peak demand.

Q: What maintenance is required for an APFC bank?

We recommend annual capacitance testing, thermal imaging of contactor terminations, and cleaning of ventilation intake filters. Our service contracts include complete annual APFC health checks.

Overview

Automatic Power Factor Correction (APFC)

Nairobi Power Engineers designs and builds custom Automatic Power Factor Correction (APFC) panelboards from 25 kvar to 1200 kvar. Our systems monitor instantaneous reactive power demand and automatically switch capacitor stages in and out to maintain a stable, compliant power factor (typically 0.98 – 0.99 lagging).

Built around the industry-leading Lovato Electric DCRG/DCRL controller family and Lovato BF...K damping contactors, our APFC banks feature self-healing metallized polypropylene capacitors, internal discharge resistors, step indicator lamps, and forced cooling.

Product Lineup

Equipment & Range Highlights

Lovato Electric • Controller

Lovato DCRG8 Advanced APFC Controller

Microprocessor power factor controller with graphic backlit LCD, 8 to 16 relay step outputs, temperature sensing, and THD monitoring.

Steps8 Standard (Expandable to 16)

AccuracyTrue RMS Class 0.5

AlarmsOver-Temp, Over-Current, THD

Lovato BF...K • Inrush Damping

Lovato Dedicated Capacitor Switching Contactors

Heavy-duty contactors with quick-break auxiliary contacts and pre-insertion damping resistors to suppress destructive capacitor inrush currents.

RatingUp to 100 kvar per step

Inrush Limit< 30 × In Peak

Endurance> 200,000 Switching Cycles

Technical Specifications

APFC Bank Technical Data

Parameter	Specification Details
Total Bank Capacity Range	25 kvar to 1200 kvar (modular step sizing: 5, 10, 25, 50, 100 kvar)
Capacitor Voltage Rating	440 V / 480 V / 525 V continuous (50 Hz)
Discharge Resistors	Integral safety resistors discharge capacitors to < 50V within 60 seconds
Switching Technology	Lovato BF...K damping contactors or Thyristor Solid-State (for fast welding loads)
Target Power Factor	Programmable from 0.80 inductive to 0.80 capacitive (default 0.98 ind.)
Enclosure Construction	IP31 / IP43 / IP54 Sheet Steel RAL 7035 with thermostat exhaust fans

Key Features

Engineering & Build Highlights

Microprocessor step balancing algorithms rotate step duty evenly to extend overall bank lifespan
Lovato DCRG controller logs kvar step health and alerts when individual capacitor stages degrade
Internal MCCB or switch-disconnector incomer with door interlocking for safe servicing
Individual HRC fuse or MCB protection for each capacitor step ensures isolated fault clearance
Thermostatically controlled forced ventilation prevents heat accumulation during full load duty
External current transformer (CT) input (5A secondary) compatible with standard switchboard CTs

Applications

Target Applications & Sectors

Agro-processing grain mills & tea factoriesCommercial office buildings & shopping mallsPlastic injection & extrusion manufacturing plantsMetal fabrication & machining workshopsWater supply booster & sewage pumping stationsHotel resorts & large laundry facilities

FAQs