What is Power Factor?
Power Protection Products, Inc.
What is Power Factor
White Paper
by Dan Maxcy l 2013 Update
877-393-1223 I www.p3-inc.com
What is Power Factor?
P3 Whitepaper
WHAT IS POWER FACTOR?
By Dan Maxcy
1993 I Revised 2013
Power Factor is the ratio of Active Power to Total Power:
Active Power = Power Factor
Total Power
Active power is what we normally see as the electricity used in our facility. It is measured in kW
(Kilowatts). This is normally what the power company charges against.
Total power is what our equipment needs to be sized for in our facility. It is measured in KVA (Kilovoltamps). The Power Company may charge extra money (penalties) for a large KVA. The large KVA is
usually stated in Power Factor. Total Power is a combination of Active Power and Reactive Power.
Reactive Power takes into consideration the energy needed to build all the magnetic fields in a facility.
Your facility’s equipment must be sized large enough to handle the extra energy needed to produce these
magnetic fields. Magnetic fields are produced in ALL current-carrying equipment in a facility. This includes
Switchboards, Panelboards, Busway, wiring, all equipment, and especially MOTORS. Motors have
thousands of feet of wire, which add greatly to a facility’s Reactive Power.
Let me take a minute and talk about these magnetic fields. In an AC (Alternating Current) system, current
flow changes direction 60 times every second. This is called 60 Hertz (Hz). Each time the current changes
direction, a magnetic field is developed around ALL current-carrying parts of a circuit. This includes all the
wire in your facility and all motors. The energy needed to produce this Magnetic Field is real. You don’t see
it on your energy bill because the power is given back to the circuit in each quarter cycle. The extra current
flow is there. Therefore, you and your power company must size equipment large enough to handle the
extra energy needed to produce these magnetic fields. This is why many power companies add an extra
charge (penalty) to facilities with a large amount of reactive power.
1
©2013 Power Protection Products, Inc. All rights reserved. No part of this publication may be used, photocopied,
transmitted, or stored in any retrieval system of any nature, without the written permission of the copyright owner.
www.p3-inc.com
Rev 2013
P3 Whitepaper
What is Power Factor?
What is a good Power Factor?
Power Factor is the ratio of Active Power to Total Power. When Reactive Power is large, Total Power
increases. With the formula below, we now see that when Total Power increases, the Power Factor
decreases.
Active Power
Total Power
Example:
1000 kW
= Power Factor
= .9 Power Factor
1100 kVA
.9 to 1 is considered a good power factor.
What is a bad Power Factor?
If we increase our Total Power.
Example:
1000 kW
1500 kVA
= .6 Power Factor
Anything less than .9 can be considered a bad power factor. Your Power Company may charge you or you
may have internal problems in your facility with Power Factors less than .9.
How do I correct for a bad Power Factor?
The best way solve a low Power Factor problem is to install Power Factor Correction Capacitors. These
Power Factor Correction Capacitors capture the energy from the collapsing magnetic field and give the
energy back on the next quarter cycle.
In summary
With these capacitors storing the energy from the magnetic fields the Power Company does not have to
supply extra power; therefore, you do not get penalized. With proper placement of these Power Factor
Correction capacitors you can control your facility’s power needs and reduce the costs of equipment to
handle large Reactive Power Loads.
©2013 Power Protection Products, Inc. All rights reserved. No part of this publication may be used, photocopied,
transmitted, or stored in any retrieval system of any nature, without the written permission of the copyright owner.
www.p3-inc.com
Rev 2013
2
P3 & PQU
Power Protection Products, Inc. (P3)
P3 specializes in representing only the best products and services that
enhance power quality. By specializing the power quality, we can
provide our customers with in-depth analysis, service and solutions that
will meet the needs of our customers and end users. P3 works closely
with your local market suppliers and vendors in order to provide you
with convenient purchasing options, sales channels and follow-up
service. We act as an extension of your current vendor base and work
closely with your local market leaders in the power quality and electrical
equipment area. In today's world of sensitive electronic equipment,
power protection is no longer an option; it's a necessity.
Power Protection Products, Inc. provides the highest quality products
and services available today that will protect and maintain your power
supply as well as reduce your downtime, equipment failure and
maintenance costs.
Learn more at PQU!
www.powerqualityuniversity.com
Power Protection Products, Inc. is "showing
you how" with Power Quality University
(PQU). Power Quality University brings real
world electrical knowledge into the
classrooms. Students are taught the importance
of power quality and the many factors which go into ensuring and
providing good power quality. The instructors who teach at PQU are
highly qualified professionals and are all experts in the field. Upon
completion of a PQU program, students can obtain Continuing
Education Credits (CEU's). PQU is just one more way that Power
Protection Products, Inc. is affecting the electrical community in a
positive way.
For more information about our service
plans and support services contact us at:
877-393-1223
1207 S. 75th Street, Omaha, NE 68124
www.p3-inc.com
