Electrical Industry Canada Power Quality Issue - 18

POWER QUALITY:
WHEN YOU ONLY WANT WHAT YOU NEED
BY MARK PETERSEN

Over many years of experience in the
electrical industry, I have learned that my
colleagues are a " get it done " group of
professionals. So, when it comes to the issues
around the power quality of electricity coming
into buildings from today's challenged grid, I
know there is frustration with the lack of
effective options. It's led to a " work around it "
approach from this group of skilled people;
they find as good a solution as is available and
they get it done.
For building owners, it has become standard
to see the sometimes significant costs of poor
power quality as " baked-in costs, " and this
gets budgeted as such, year after year. The
ELECTRICAL INDUSTRY CANADA

good news is that it doesn't have to be like
this. Today, there are effective power quality
management solutions for the commercial and
light-industrial building segments.
The fact is, electrical pros know that
electricity isn't one-dimensional, but is made
up of a number of power parameters. These
get captured under the umbrella term of
" power quality. " Technically, most power
quality issues can be categorized as a
deviation of voltage, frequency or waveforms.
The possible permutations of these in multiple
phases make for a lot of potential issues.
Here is a quick summary of key power
quality parameters and some of the building
issues that they cause:
* Sag: A short-term (less than one min)
reduction in voltage to a level less than 90% of
the nominal voltage. (Example: Less than 108V
for a 120V system.) Potential Effects:
Malfunction of IT equipment, tripping of
contactors and electromechanical relays,
disconnection and loss of efficiency in electric
rotating machines.
* Swell: A short-term (less than one min)
increase in voltage to a level greater than 110%
of the nominal voltage. (Example: Greater
than 132V for a 120V system.) Potential
Effects: Data loss, flickering of lighting and

screens, stoppage or damage of sensitive
equipment.
* Undervoltage: A long-term (greater than
one min) reduction in voltage to a level less
than 90% of the nominal voltage. (Example:
Less than 108V for a 120V system.) Potential
Effects: Elevator/escalator failure (due to
motor/controls failure), tripping of fire alarms,
etc.
* Overvoltage: A long-term (greater than one
min) increase in voltage to a level greater than
110% of the nominal voltage. (Example:
Greater than 132V for a 120V system.)
Potential Effects: Wasted excess energy
above nominal is paid for. All electrical systems
and components (motors, lighting, etc.)
receive more voltage than required/designed
for, leading to breakdowns and shortened
lifespan.
* Unbalance: A measure of the difference in
magnitude and angle of the three phases of
voltage.
Potential Effects: Decrease in
system efficiency; tripping of, or permanent
damage to, electrical equipment.
ª Transients: A very fast voltage disturbance.
Potential Effects: Tripping of protection
devices, loss of information and malfunction of
data processing equipment, stoppage of
sensitive equipment.
VOLUME 1, ISSUE 2

18
https://legendpower.com/
Electrical Industry Canada Power Quality Issue

Table of Contents for the Digital Edition of Electrical Industry Canada Power Quality Issue
