Business
and Industry, Good Business Sense
Guarding Power Quality...
When your business depends upon equipment reliability,
even minute disruptions of power can have major consequences: down
time, data loss, and even equipment damage. In the past, this was
much less of a problem, as older electrical equipment was more tolerant
of power quality. Motors, solenoids, and electromechanical controls
simply don't notice minor disturbances. But today's electronics
are much more demanding. Computers, micro processors, telecommunications
equipment, process controls, and robotics and automation demand
"clean" power...
The power that comes to your BHP meter meets
ANSI guidelines for power quality. Unfortunately, there are occurrences
outside the control of BHP that can cause your power supply to be
disrupted, or deviate from normal. Also, factors within your business
can cause power deviations that could disrupt sensitive electronic
equipment. Some types of power deviations are shown in the following
table:
| Problem |
Definition |
Duration |
Cause |
Effect |
| Outage |
Planned or accidental total loss of
power in a localized area. A blackout is a wide-ranging outage. |
Minutes to a few days. |
Catastrophic system failure, weather,
small animals, human error (auto accidents, kites, etc.). |
System shutdowns. |
| Dropout |
A very short planned or accidental
power loss. |
1 millisecond to 1 second. |
Utility switching operations attempting
to maintain power to your area despite a failure somewhere
else on the system. |
Equipment resets, data loss. |
| Sag/Surge |
A decrease or increase in voltage
above or below the normal voltage level (also called an over-
or under-voltage). |
Less than 2.5 seconds. |
Heavy load switching, air conditioning,
disk drives, transformers, and other equipment drawing large
amounts of power. |
Memory loss, data errors, flickering
or dimming lights, shrinking display screen, equipment shutdown. |
| Spike |
A sharp, sudden increase or decrease
in voltage of up to several thousand volts. Also called an
impulse, transient or notch. |
1 microsecond to 1 millisecond. |
Utility switching operations, on-and-off
switching of heavy equipment/office machinery, SCR's firing,
elevators, welding equipment, static discharges, lightning. |
Loss of data, burned circuit boards.
|
| Noise |
A high frequency interference from
7,000 Hz to 50 MHz. |
Usually of constant duration. |
Electromagnetic interference, microwave,
radar, radio and TV transmissions, arc welding, heaters, printers,
thermostats, electric typewriters, loose wiring, improper
grounds. |
Although generally not destructive,
it can garble or wipe out stored data. |
There are steps you can take to protect power
quality. Some of them are simple, some are not so simple. The degree
of protection you choose should be based upon what you stand to
lose in the event of power deviation. A BHP technical advisor can
recommend the power quality assurances that fit your needs: These
include:
- Proper Wiring and Ground:
The most common causes of power quality problems are the simplest.
The importance of a good, low-resistance ground cannot be overemphasized.
Inadequate wire sizing, loose connections, or dust and dirt from
poor maintenance are also problem-causers. Checking these things
are the lower-cost way to prevent or cure power quality problems.
- Dedicated Circuits: Critical
and sensitive electronics should be located on their own independent
circuit. This isolates them from power quality problems arising
within your business. A dedicated circuit also prevent overloads...
- Spike Suppressors: These
help eliminate many sudden changes in voltage, but beware: You
get what you pay for! Their capability depends upon the quality
of the device purchased.
- Major Steps: If uninterrupted,
clean power is vital to your business. You should consider taking
major steps toward power quality control. These can range from
fairly simple isolation transformers and voltage regulators all
the way up to uninterruptible power supplies or generator sets.
A BHP Representative
can help you explore your options.
SurgeGuard
Power Quality Solution: BHP offers customized programs including
surge suppressors, UPS systems, and cable/telephone protection for
small businesses who are BHP customers. For more information, contact
a BHP Representative.
|