Power Factor Correction is a device that is installed on an electrical system to improve the overall electrical efficiency known as power factor of an electrical supply that operates machines or motors.
All motors which can come in the form of a machine, conveyor, mixer, compressor, HVAC, refrigeration, elevator or escalator etc all have an efficiency rating known as power factor.
The ultimate desired power factor is 1.00pf (100% efficient) although most motors operate at a much lower efficiency or power factor which when the effects are accumulated on an electrical supply, the results can be as low at 0.50 power factor and commonly around 0.80 power factor on a typical uncorrected industrial electrical supply.
The solution is to install a power factor correction system which works by switching capacitors in and out of circuit on an electrical supply to counteract the negative inefficient effects of motors automatically.
A typical uncorrected industrial electrical supply operating in the region of 0.80 power factor (80% efficient) would consume 20% more power and operate with a demand 20% higher than need be resulting in higher energy bills.
Other electrical supplies operating on much lower uncorrected power factors could be consuming in excess of 50% more power and risk potential overload and loss of electrical supply through brownout.
Savings & Benefits of Power Factor Correction
The financial savings & benefits of power factor correction can by substantial and generally are achievable from the following areas:
- Reduction in power consumption kw/h losses
- Removal of penalties on electricity bill in the form of reactive power charges
- Reduction in capacity charges / authorised supply capacity
- Removal or reduction of excess charges
- Reduction in carbon emissions
- Reduction in maximum demand and demand based charges
- Reduction in circuit currents
- Improvement in power quality
The payback period of power factor correction is typically between 1 – 3 years dependant mainly on three things:
- The degree of inefficiency to be corrected
- The structure and type of the electricity bill
- Type of power factor correction required
Types of Power Factor Correction
There are many different types of power factor correction and although the principals remain the same, it is vital that expert advice is sought to ensure the correct solution is implemented.
How is Power Factor Correction Installed
Installation of power factor correction is carried out in parallel with the main electrical supply like most common electrical devices and via a suitably rated form of protective device like MCCB or fused switch although individual “local” power factor correction capacitors can also be installed on individual motor loads.
In addition to the automatic power factor correction capacitor bank supply, a CT (Current Transformer) should be installed onto the main incoming cables to the power supply to be corrected (normally main incoming supply to the site) in order to “see” and monitor the total load including the capacitor load (power factor correction) and report this to the power factor controller.
When installing power factor correction on individual motor loads it is important to ensure over compensation cannot occur and that any associated controls will allow for the capacitor to discharge between energization periods.
For more information or help to specify the correct power factor correction for your site, contact our offices on 01695 559785 or email firstname.lastname@example.org
For more information on power factor correction click on this link
For more information on the EnergyAce power factor correction system specification click on this link
For independent information on power factor correction from the Carbon Trust, click on this link