Industrial service upgrade

[mtnmod]

I have some questions caused by connecting a PV array to our service. First currently our utility service has two separate incoming 3ph voltages 208v and 480v, the utility is requiring us to change to 480v only. We will be required to transform down to 208v. We have two 208v panels and one 480v panel thus requiring two transformers for our 208v. The PV will interface our 480v panel. Our 480v power factor is currently below 90% thus I was wondering if the transformers will have any effect on our power factor after the change to 480v only. Also our 208v PF is 95% now. We realize a capacitor bank may be required anyway.

 

[lielec11]

What type of loads do you have on each service (lighting, motors, UPS, etc.???), this is usually the biggest factor for lower power factor. The utility could also be the cause of a lower power factor as well.

However, how much lower than 0.9 is it? Anything above 0.8 is typically considered good. What type of facility is it?

 

[beanland]

Power Factor

Power Factor

Good choice to feed each 208Y/120V panel from an appropriately sized step-down fed from 480V panel. Power factor for composite load will be based on total real and reactive power from 480V added to real and reactive power in 208V load, not the PF of each. Each step-down transformer will add some reactive power losses tending to lower overall power factor. Load flow calculations will be needed.

Some PV systems can supply reactive power, depends on inverter design. You might be able to improve power factor.