Download Don`t Be Left In The Dark - Maryland Public Service Commission

Power
outages are inconvenient for customers and
costly to the utility. Electric customers must make do
without lights, cooling and heating until service is
restored. Restoration efforts can be very costly to the
utility and can sometimes take several days to complete
if the damage is widespread.
There are many causes for power interruptions – some
preventable and some not. The most common causes
are:
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Lightning
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Automobile accidents
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Wildlife
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Excavation
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Storms
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High winds
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Snow or ice
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Vandalism
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Equipment failure
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Overgrown trees
Abnormal conditions (such as lightning) can cause an
open circuit, a ground, or a short circuit. These are called
“faults.” An open circuit occurs when one or more
conductors are broken and the broken ends separate.
A conductor which contacts the earth causes a ground;
the electricity flows out of the circuit into the earth. A
short circuit occurs when a connection is accidentally
established between two conductors, causing an
overload on one or more conductors.
REPORTING OUTAGES
Outages should be reported directly to the utility.
However, you should first check with neighbors to
determine if the outage has already been reported
before making your call. By reducing duplication of
reports, the utility’s telephone lines can be kept open to
receive emergency reports of downed power lines and
outage reports from other areas.
Utility customers often call the PSC to request help in
expediting restoration of their electric service during a
power outage. Unfortunately, the PSC does not direct
the utilities’ field crews and cannot expedite restoration.
However, customers reporting extreme medical
emergencies (such as life support equipment on
premisis) are reported to the utility. Customers with
medical concerns should submit medical certification to
the utility so that the account can be noted that a
medical condition exists.
If someone in your home has a medical condition that
could be aggravated by a power outage, you should
develop a plan for relocating the patient during an
outage or have battery or generator backup available.
PREVENTIVE MEASURES
Code of Maryland Regulations 20.50.02.01 requires utilities
to provide safe, reliable, and adequate service. The
regulation specifically requires that “the electric plant of
the utility shall be constructed, installed, maintained
and operated in accordance with accepted good
engineering practice in the electric industry to assure, as
far as reasonably possible, continuity of service,
uniformity in the quality of service furnished, and the
safety of persons and property.”
It is impossible to prevent outages entirely. However,
utilities use preventive measures, such as those listed
below, to improve reliability of service:
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Lightning arrestors
Grounded shield wire
Tree-trimming
Tree wire and fully insulated aerial cable or
partially insulated cable in heavily treed areas.
Wildlife protection (squirrel guards)
Regular inspections using ground and aerial
patrols
A recloser, which is another type of switch located on
main lines, opens the circuit in case of a fault as would
a fuse or circuit breaker. However, reclosers open the
circuit temporarily and then reclose it several times,
thus maintaining the circuit in the event of a temporary
fault. (A tree limb brushing against a conductor is an
example of a temporary fault).
Although the
momentary outages that result can be annoying,
causing the need for resetting digital clocks, etc.,
reclosers are effective in reducing outages of longer
duration.
Other devices, called sectionalizers, are used to isolate the
location of permanent faults on distribution circuits,
keeping the number of customers out of service to a
minimum. These devices are usually installed on lines
off the main circuit.
TREE TRIMMING
While there are no Public Service Commission
guidelines or regulations specifically concerning a
utility’s tree trimming practices, tree trimming is one of
the accepted methods used by a utility to maintain its
equipment. In past years, tree trimming was primarily
done only when utilities received reports of trees
causing outages or safety hazards. However, in the last
few years, most utilities have begun “Vegetation
Maintenance Programs,” which involve trimming back
growth near the utility’s lines according to a regular
maintenance schedule. Tree trimming is also
performed, as needed to correct existing tree
interference or safety hazards.
BE PREPARED
PROTECTIVE DEVICES
In addition to the preventive measures listed above, an
additional system of protective devices helps to limit
outages to localized areas.
Circuit breakers are switches located in substations,
which automatically interrupt the flow of electricity
during overloads or short circuits. Fuses perform the
same function on distribution lines.
Whether or not you experience frequent power
outages, you should be prepared in the event an outage
occurs. The following items can help you prepare for a
loss of power:
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Flashlights and/or battery-powered lanterns with
fresh batteries
Candles and matches (use with extreme caution)
Bottled water
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Non-perishable food (such as canned food) and a
manual can opener
Battery-operated radio with fresh batteries
First aid kit
Propane grill, charcoal grill or camp stove
SURGE PROTECTION
Most homes and businesses have an array of electronic
equipment that is sensitive to power surges. Solid State
technologies using microchips have made home and
office equipment sensitive to electrical spikes, surges
and fluctuations in voltage. Such interference can both
damage and affect the performance of valuable
equipment such as TVs, VCRs, computers and major
appliances.
Electric utilities install special equipment (lightning
arrestors and wild life protections) to minimize the
number of occurrences to its primary equipment.
While these are efficient, some fluctuations in voltage
are simply unavoidable. The utility is NOT required
to replace or repair equipment damaged as a result
of a fluctuation in voltage, such as a surge.
Therefore, you should consider high quality surge
protectors to reduce the risk of surge damage. Some
utilities provide surge protection for an additional cost.
(This service is not regulated by the PSC). In addition, surge
protection equipment is available at most retail stores
or through an electrical contractor.
If surge
protection is not available or not affordable,
sensitive equipment should be unplugged during
electrical storms or outages to avoid possible surge
damage when power returns.
LOSSES DUE TO OUTAGES/SURGES
Generally, utility companies are not liable for damages
due to power outages/surges unless damage resulted
from willful neglect by the utility. However, allegations
of willful neglect can only be decided by a court of law.
The PSC cannot adjudicate damage claims. You
should consult with your insurance agent to find out if
your homeowner or renter’s policy covers losses due to
power outages.
RELIABILITY OF SERVICE
No utility can guarantee uninterrupted service. Code of
Maryland Regulations 20.50.07.05 provides that “[e]ach
utility shall make reasonable efforts to avoid
interruptions of service, but when interruptions occur,
service shall be re-established within the shortest time
practicable, consistent with safety.”
Utilities are required to report any major and sustained
outage to the Commission including information
regarding the cause, date and time and duration of the
outage. The PSC monitors the restoration efforts of
the utility during widespread power outages.
Additionally, the PSC monitors the reliability and safety
of the electric system and ensures that appropriate
system improvements are performed. Our Engineering
Division performs site inspections and work with the
utilities to ensure that the least reliable feeders that are
not performing well one year improve over the next
several years.
FREQUENT OUTAGES
When the PSC receives complaints about frequent
power outages in a community, we request a thorough
investigation by the utility. The utility provides the
PSC with the dates, duration, and cause (if known) of
the outages, and any efforts already undertaken by the
utility to improve reliability, as well as any
improvements planned for the future. If necessary, the
PSC’s Engineering Division is consulted to determine
whether the utility’s efforts are adequate and
appropriate to improve service reliability. Remember, the
utility does not guarantee uninterrupted service and the PSC
cannot assist you in obtaining compensation for losses resulting
from a power outage. The PSC’s role in examining
complaints of frequent outages is focused on quick
restoration and prevention of future outages.
MD Public Service Commission
William Donald Schaefer Tower
6 St. Paul Street
Baltimore, MD 21202-6806
1(800) 492-0474
or (410) 767-8028
Fax: (410) 333-6844
Internet: www.psc.state.md.us/psc
about power outages
Causes, Prevention & Restoration