POWER FACTOR

Phasetech Limited Industry Park, Cricketts Lane Chippenham, Wiltshire SN15 3EQ Tel:  +44 (0)1249 651436 Fax: +44 (0)1249 462356 sales@phasetech.co.uk

POWER FACTOR CORRECTION

Any industrial process using electric motors (to drive pumps, fans, conveyors, refrigeration plant etc.) introduces inefficiencies into the electricity supply network by drawing additional currents, called "inductive reactive currents".

Although these currents produce no useful power, they increase the load on the electricity company's switchgear and distribution network and on the consumer's switchgear and cabling. The inefficiency is expressed as the ratio of useful power to total power (KW/KVA), known as Power Factor. This can be shown vectorially as:-

where KVAr represents inductive reactive power 0 is lagging phase angle and cos 0 is power factor.

Typical uncorrected industrial power factor is 0.8. This means that a 1MVA transformer can only supply 800KW or that a consumer can only draw 80 useful Amps from a 100Amp supply. To put it the other way, a 3-phase 100KW load would draw 172A per phase instead of the 139A expected.

To discourage these inefficiencies the electricity companies charge for this wasted power. These charges appear on electricity bills as "reactive power charges", "KVA maximum demand" or "KVA availability charges".

These excess currents and associated charges can be removed by a well established technology called "POWER FACTOR CORRECTION". Simply put, this technology offsets the inductive reactive currents by introducing equal and opposite capacitive reactive currents.

Typically this can reduce electricity bills by 5-8%, with a payback period of 12 to 18 months. Or, if a consumer is at the limit of his supply availability it can release up to 20% more power.

Phasetech Ltd supply, install, commission and maintain Power Factor Correction Equipment. We can offer free surveys to tell you what improvements are available, how much could be saved and what it would cost.