Automatic power factor correction · APFC
APFC panels
Keeps your power factor close to unity as the load changes. An APFC panel measures reactive power continuously and switches capacitor steps in and out to cancel it, lowering your electricity bill and freeing up transformer and cable capacity.
- Capacity
- 50 to 1000 kVAr
- Target PF
- 0.95 to unity
- Steps
- Up to 12
- Switching
- Contactor or thyristor
Overview
Many Indian utilities bill on kVAh or charge penalties for low power factor, so reactive power shows up directly on the bill. We size the APFC panel from your maximum demand, existing power factor and load profile, and split it into steps small enough to track your load closely.
Where your load includes VFDs, UPS systems or other non-linear equipment, plain capacitors can resonate with the network and fail early. For these sites we fit detuned reactors, chosen after a harmonic check, so the capacitors are protected and harmonics are not amplified.
Technical specifications
| Rated voltage | 415 V AC, 3-phase, 50 Hz |
|---|---|
| Capacity | 50 to 1000 kVAr |
| Controller | Microprocessor APFC relay, 6 to 12 steps, with display and alarm contacts |
| Capacitors | Heavy-duty MPP or APP, rated 440, 480 or 525 V depending on reactor and harmonics |
| Switching | Capacitor-duty contactors with pre-charge resistors, or thyristor switches for fast-changing loads |
| Detuned reactors | 7% (189 Hz) or 14% (134 Hz), copper or aluminium wound |
| Step protection | MCCB or HRC fuses on each step |
| Incomer | MCCB or ACB with metering |
| Cooling | Thermostat-controlled exhaust fans and louvered doors |
| Target power factor | Adjustable, typically 0.95 to unity |
| Enclosure | CRCA sheet steel, 2 mm structure and 1.6 mm doors |
| Degree of protection | IP42, indoor |
| Finish | Powder coat, RAL 7035 or your shade |
| Standards | IS 8623; capacitors to IS 13340 / IEC 60831 |
What's inside
- Incomer with multifunction meter showing PF, kVAr and harmonics
- APFC relay that measures and switches steps in sequence
- Capacitor banks sized in steps, for example 25 + 50 + 50 + 100 kVAr
- Capacitor-duty contactors or thyristor switches per step
- Detuned reactors where the network carries harmonics
- Exhaust fans, thermostats and step-wise fuses or MCCBs
Applications
- Factories with induction motors
- Commercial buildings on kVAh tariffs
- Plants with VFD and UPS loads (detuned)
- Welding, cranes and presses (thyristor switched)
- Hospitals and hotels
- Pumping and irrigation stations
Options
- Thyristor switching for real-time correction
- Detuned or tuned harmonic filters
- Communication-enabled relay (Modbus)
- Temperature and over-voltage step lockout
- Outdoor IP54 enclosure
- Combined PCC + APFC lineup
Built and tested in-house
We cut, bend, weld and powder-coat the enclosures in our own workshop, then assemble and wire every panel to drawings you approve before fabrication starts. Before dispatch each panel goes through high-voltage, insulation resistance and functional tests, and your team is welcome to witness them.
Frequently asked questions
How do I know what kVAr rating I need?
Share your electricity bills or load data. We calculate kVAr from your maximum demand and the change from your current power factor to the target, then add margin for future load. A quick rule is roughly 30 to 40 percent of your kW load, but we always size from real data.
What is a detuned APFC panel?
It adds a reactor in series with each capacitor step, tuning the step below the 5th harmonic. This stops the capacitors from resonating with harmonics from VFDs and UPS systems, which would otherwise overheat and damage them.
Contactor or thyristor switching?
Contactors suit loads that change over minutes. Thyristor switching responds within a cycle and suits welding machines, cranes and presses, where load swings too fast for contactors and frequent switching would wear them out.
How much can an APFC panel save?
It depends on your tariff and present power factor. On kVAh billing, raising the power factor from 0.85 to 0.99 cuts the billed kVAh for the same kWh by about 14 percent.
Other panels in the range
Need an APFC panel?
Share your single-line diagram, load list or specification and we'll come back with a GA drawing, a bill of materials and a price. Most enquiries get a first response within two working days.
- sales@indway.in
- Phone
- +91 98705 97616