Switchboard Services (Pty) Ltd

Low Voltage Switchboard Manufacturing & Field services


What is Power Factor?

In AC circuits, the power factor is the ratio of the real power that is used to do work and the apparent power that is supplied to the circuit. The power factor can get values in the range from 0 to 1. When all the power is reactive power with no real power (usually inductive load) - the power factor is 0.

In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. The higher currents increase the energy lost in the distribution system, and require larger wires and other equipment. Because of the costs of larger equipment and wasted energy, electrical utilities will usually charge a higher cost to industrial or commercial customers where there is a low power factor.

Power Factor correction

A high power factor is generally desirable in a transmission system to reduce transmission losses and improve voltage regulation at the load. It is often desirable to adjust the power factor of a system to near 1.0. When reactive elements supply or absorb reactive power near the load, the apparent power is reduced. Power factor correction may be applied by an electric power transmission utility to improve the stability and efficiency of the transmission network. Individual electrical customers who are charged by their utility for low power factor may install correction equipment to reduce those costs. Power factor correction brings the power factor of an AC power circuit closer to 1 by supplying reactive power of opposite sign, adding capacitors or inductors that act to cancel the inductive or capacitive effects of the load, respectively

We do Power Factor recordings & provide a full report of values received from the recording, with the values received we can work out the correct size Power Factor Correction Panel needed to suit your current load, changing your Power Factor closer to 1, Thus saving you money!

Power factor systems (automatic) 400/440V
For applications with changing capacitor requirements an automatic reactive controller monitors the network and
only switches required capacitor banks as and when they are required.
FM series floor standing systems (137 - 900 kvar - 400V)
Complete ready-to-install, suitably ventilated floor standing system comprising:
• Mains isolator, door interlocking (with early make/late break auxiliary contact)
• Automatic reactive control relay (incorporating digital display of all important network parameters)
• Suitably rated “special” capacitor switching contactors

FM series floor standing complete power factor systems (440V capacitors)
• Reverse-flow roof mounted exhaust fan (for improved cooling and ventilation)
• Bottom cable entry (top entry on request)
• RC series racks - heavy duty capacitors
- “special” capacitor switching contactors
- fusegear and busbars per capacitor bank