Product: Power Factor & Harmonics: StacoVAR: Let's Discuss Power Factor Correction

1. StacoVAR: Power Factor
Correction

2. POWER FACTOR
CORRECTION (PFC)
Power Factor (PF):
Term used in regard to the efficiency of
an electrical power distribution system.
Power factor is a measurement
between the current and voltage phase
shift waveforms.

3. PF COMPONENTS
Power factor consist of 3 components:
• KW, which is the working, or real, power
(does the actual work)
• KVA, which is called the apparent power
(relationship between KW and KVAR)
• KVAR, or reactive power
(does not do any beneficial work)

4. DETERMINE YOUR PF
Divide the working power (KW) by the
apparent power (KVA)
PF of 1, or unity, being the highest (or best)
power factor possible.
When correcting PF, in general, a measurement
of .9 or higher is considered good.

5. INDUSTRIES KNOWN TO
HAVE POOR PF
Industries where power factor problems
are common:
o Steel/Foundries
o Chemicals
o Textiles
o Pulp and paper processing
o Automotive and other automated assembly
o Rubber and plastics processing
o Breweries
o Electroplating

6. CAUSES OF PF PROBLEMS
Loads that cause power factor problems:
o Induction motors
o Electric arc furnaces
o Machining
o Stamping
o Welding
o Variable Frequency Drives (VFDs)
o Fluorescent lights with magnetic ballasts
o Computers
o Computer controlled equipment

7. BENEFITS OF IMPROVING
PF
Improving PF:
o Lowers your electrical cost
o Increases KVA capacity (increase the
KW used for the same KVA)
o Improves voltage regulation
o Allows for the size reductions in
cables, transformers and switchgear
o Allows for expansion without additional
electrical improvements

8. UTILITY COMPANY’S POINT
OF VIEW
Raising the average operating
PF of the entire grid network
from .70 to .90 means:
oReduced costs from inefficiencies
oIncreased generation and distribution
potential
oLower demand on the grid

9. BETTER PF MEANS
Utilities can save hundreds of thousands of tons of
fuel (and produce fewer emissions), have more
transformers available, and reduce building new
power plants and their support systems.
This is why more utility companies are starting to
charge a “Power Factor Penalty” so they can
recover additional cost they incur from
supporting an inefficient system.

10. PF IMPROVEMENT
EXAMPLE
Assume you have a load of 100kVA with a PF
of .80, then you have enough power to light 800
100-wattlight bulbs. If you improve the PF to .95,
you now have enough power to light 950 100-watt
light bulbs.

11. PF IMPROVEMENTS CAN
SAVE $
Because power factor correction
capacitors:
o Use less energy
o Lengthen the life of equipment
o Reduce electrical requirements for any new or future
equipment that is installed

12. UTILITY KVA BILLING
Most utilities use the kVA billing method
therefore:
o You are charged for the current your system draws from the grid
o Many utilities add a surcharge or adjustment for PF.
o Special tariffs applied
o Interruptible rates applied
o Off-peak rates
Some utilities give credits or bonuses for higher than average
PF, or one that is above a predetermined level

13. EXAMPLE
Most utilities use the kVA billing method therefore:
o You are charged for the current your system draws from the grid
o Many utilities add a surcharge or adjustment for PF.
o Special tariffs applied
o Interruptible rates applied
o Off-peak rates
Some utilities give credits or bonuses for higher than average
PF, or one that is above a predetermined level

14. RETURN ON INVESTMENT
(ROI)
Using the previous example, if you
are billed at $11.22 per kVA:
o100kW @ .70 PF = 142 kVA,
or $1,593
o100kW @ .95 PF = 105 kVA,
or $1,178
This represents a monthly savings of $415, or
$4,980 annually. Assuming the equipment cost
was $5,600 the ROI would be about 14 months.
After this period there can be an ongoing 26%
savings.

15. PF CORRECTION
CAPACITORS
A capacitor’s function is to:
o Provide kilovars to a system at the point of
connection
o Improve PF
o Reduce lagging components on the circuit
o Reduce power losses
o Reduce kVA load.
o Provide reactive power to replace the
VARs wasted by an inefficient load

16. PF CORRECTION
CAPACITORS
Are the most economical means
of improving PF because of
their:
oRelative Low Cost
oEasy Installation
oLow Installation Cost
oMinimal Maintenance
oHigh Efficiency and Low Losses

17. DETERMINING THE PF
Find poor PF problems by:
oMonitoring at the incoming service entrance
or at specific loads can identify problems
within a facility
o Conduct a Facility Power Study and have
reviewed by a power analyst / consultant
Some utilities offer analysis for businesses
wanting to improve their efficiency.

18. TYPES OF CAPACITOR
SYSTEMS
oSimple small fixed capacitors can be
installed at a single motor to be switched on
and off with the load, this is ideal.
• However, this can be expensive, and
can create technical problems, since it
may require a large number of low-
power units at several points throughout
the facility, making it difficult to monitor
and maintain over time

19. TYPES OF CAPACITOR
SYSTEMS
oAutomatic capacitor bank installed on the
bus bars of the distribution panel. This
method provides centralized PF
correction for an entire facility.
• It also allows for fixed capacitors to be added
to correct the power of any piece of
equipment that causes a significant problem.

20. INSTALLATIONS LOCATIONS

21. NEXT STEP - DETERMINE
THE KVAR
After you have determined what type capacitor
system you need, the next step is to determine
the size or amount of kVAR, you need to correct
the PF.
Staco Energy Products Co. has easy to use
tables that will assist you in determining the
required kVAR you need to add to your system
to improve the PF.

22. NEXT STEP
Example: If your existing PF is .71 and you want to bring it
up to .95, the number in the table is .663 (kW multiplier).
Multiply .663 by the number of kW your system uses (say
590). The total kVAR would require 390 kVAR, which would
be rounded up to 400 kVAR. Therefore a 400kVAr rated unit
would be used.

23. FINAL STEP
Purchase a Staco
Automatic Switched
400 kVAR StacoVAR
System,
OF COURSE!

24. FIXED CAPACITOR
ASSEMBLIES
Fixed capacitor assemblies, also called motor load
capacitors, are ideal for improving PF where
induction motors are located. They are also used
anywhere there are small kVAR requirements.
You can achieve maximum benefits from capacitors
when located at the load. Because the capacitor is
Usually switched on and off with the load, over
correction is also avoided

25. SIZING FIXED CAPACITORS
Capacitors must be carefully sized when switched
with the motor as a unit, because:
o Dangerous over voltages and transient torques can
occur if the kVAR exceeds the motor’s magnetizing
current

26. WHAT YOU NEED TO KNOW!
When sizing fixed capacitors you
need the following
Motor information:
oU-Frame (U, T etc.)
oNEMA Class (B, 2B, C, D etc.)
oA or B Normal Starting Torque – Normal
Running Current

27. INSTALLATION LOCATIONS
1. Motor Side of Overload Relay
o Use this for new motor installations where overloads
can be sized in reference to reduced current draw
o Existing motors where no overload change is needed
2. Motor Side of Starter
o Use this for existing motors when the overload rating
exceeds code
3. Line Side of Starter
o Use this for Multi-speed motors
o Motors that are jogged or reversed
o Motors that star frequently
o Starters that disconnect/reconnect capacitors during
cycle and starters with open transitions
o High inertia loads, when disconnecting the motor with
the capacitor turns the motor into a self-exciting
generator

28. INSTALLATION LOCATIONS

29. MOTOR REFERENCE
TABLES
Staco Energy Products Co. has
all the reference tables
available to make it easier to
select and size the correct
StacoVAR Motor Load
Capacitor for your application.

30. STACOVAR SOLUTIONS
Staco Energy provides various solutions,
specific to correction of poor power
factor and/or harmonics. Equipment
available:
o Fixed capacitors from 2 to 400kvar.
o Automatically switched type from 75 to
600kvar (240vac) and 100 to 2400kvar (480
and 600vac).

31. STACOVAR FIXED MODELS
Fixed Power Factor Correction: PF
Model
o Wall mounted/freestanding motor load “ML”
products include liquid filled long life three phase
power capacitors and freestanding (larger kvar)
products with heavy duty, dry type three phase
power capacitors, and both types include
discharge resistors and over pressure protection.
o Fixed only, no switching, no control, located at
individual motor loads.

32. STACOVAR STANDARD
FEATURES
Automatic Power Factor Correction Standard Features:
o NEMA 1 enclosure, with bottom entry access and modular
design allowing for easy future expansion.
o UL 508A listed, complete assembly.
o Heavy duty, dry type three phase power capacitors, with
discharge resistors and over pressure protection.
o PA units accommodate up to 10% THD environment.
o (PH, PT, and PR units use 480 volt rated capacitors for 240 volt
system and 690 volt rated capacitors for 480 volt system, for
even higher harmonic level protection).
o 5-year warranty on the capacitors.
o Individual step fuse protection (200kaic) with blown fuse
indication.
o Control power transformer with fused primary & secondary, and
nickel-plated electrical grade cooper bus bar system.

33. STACOVAR AUTOMATIC PA
MODELS
Automatic Power Factor Correction:
PA Model
Additional features:
o Type of Switching: Electro-mechanical contactors with
damping resistors to reduce switching inrush currents.
o Controller: adjustable (0.5 to 300) second response
microprocessor based power factor controller (twelve-step
regulation) with front panel LED display.
o Automatically switched (contactors), basic, economical.
Product accommodates most requirements.

34. STACOVAR AUTOMATIC PH
MODELS
Automatic Power Factor Correction:
PH Model
Additional features:
o Type of Switching: Electro-mechanical, heavy duty contactors.
o Controller: adjustable (0.5 to 300) second response
microprocessor based power factor controller (twelve-step
regulation) with front panel LED display.
o Reactor: Three phase 5TH order, iron-core reactors with a
227hz tuning frequency.
o Automatically switched (contactors), for a harmonic
environment where capacitors may be damaged. Use of iron-
core reactors necessary for a detuning - majority of
requirements for the 5th order. Product accommodates many
applications and is cost effective.

35. STACOVAR OPTIONS
Automatic Power Factor Correction
Options:
o Circuit Breakers: Circuit breakers are three-pole molded
case type, with a thermal-magnetic trip. Amperes are
based upon breaker frame size. Circuit Breaker option
may increase standard cabinet dimensions, consult
factory for sizing.
o TVSS – Surge Protection.
o CT – Current Transformer: multi-tap, (3000:5, 2500:5,
2200:5, 2000:5, 1500:5, 1200:5, 1000:5, 800:5, 500:5,
300:5), split core type for ease of installation. CT’s
shipped loose. 1-5% accuracy depending on ratio.

36. QUESTIONS?
Toll Free: 866.261.1191 | sales@stacoenergy.com | www.stacoenergy.com