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EDZ engineers and technical teams are significantly experienced in the installation, distribution and
maintenance of Medium Voltage and Low Voltage (MV/LV) networks and distribution
transformer stations.
During the past 6 years and by utilizing the GIS technology, EDZ has been able to reduce the over all
technical and non-technical losses for both MV and LV lines from 30% to less
than 9% of the total energy, which is the lowest in Lebanon and probably the
region.
EDZ engineers and technical teams insure a 24hrs/24 and 7days/week presence for trouble call services. All
operation and maintenance works are carried out entirely by EDZ teams, whom are
equipped with all necessary and latest testing tools for electrical works to be
carried in conformance with international standards.
To
take a look at some general
tabular and geographic
information about EDZ MV lines,
follow the link provided below:
-
Feeder Statistics
Section Contents
- Operation
- Maintenance
Operation
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EDZ
installation methods for medium
and low Voltage distribution
basically follow the
international standards and
norms. At EDZ we emphasize on
following procedures to limit
energy losses some of which are
listed below:
· Installation of surge voltage devices and
overhead earth continuity
conductors to tremendously
reduce MV lines outages
associated with bad weather
conditions.
· Utilization of the Remote Medium Voltage Lines
Fault Indication system to
quickly react to any fault
condition.
· Utilization of powerful GIS load flow calculations to assure a voltage drop of less than 4% at the
furthest end of any LV network.
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· Utilization
of
Medium Voltage lines change over
technique, bouclage, by
installing MV switch gears in
critical locations on the
network so that any MV line
under cutout could be recovered
by another line following
predetermined procedures.
· Reduction of the over heating of connections by installing pressure type cable lugs.
·
Decrease of transformer burn outs by installing on every unit:
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Surges protection devices.
- Disconnection switches.
- Drop out fuses at the transformer primary side.
- Calibrated Thermal and Magnetic circuit breakers at the transformer secondary side with adequate
breaking capacity.
· Monitoring of all MV/LV substations output by sequentially installing a special apparatus called
"Analyzer" that records minute by minute substation information such as
voltage, current, power factor, max. Volt, max. Amp etc… for later analysis.
·
Reduction of fraud by applying:
- Monthly calculation of technical energy losses value by using an advanced load flow technique
developed on top of our GIS system.
- Around the clock surveillance of low voltage network.
- Consecutive on site inspection of meters by the use of a special portable apparatus "Etalon MTE".
- Replacement of most LV overhead bare conductors with twisted and isolated type cables (Torsade).
- Reallocation of all energy meters by installing them at the customers' residences entrances where
they can be easily inspected.
- Issuing directions to our customers in order to restrain tampering and illegal hook ups to the grid
and guiding them to efficiently use power supply.
Maintenance
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One of EDZ main and most important tasks is the term maintenance schedule of all MV/LV networks and
transformers substations.
During the years we were able to achieve fewer incidents of line faults and transformer burning outs by applying the following yearly maintenance schedule.
Following is EDZ yearly maintenance schedule and main activities:
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A-
MV
lines Maintenance Schedule
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Duration
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Activity
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3-month period
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Porcelain isolators cleaning
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Tightening of all MV connectors
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Sept - Nov
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Checking overhead line sags
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Cleaning of all MV switching and protection devices
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Checking and repairing all moving parts mechanisms
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Calibration of spark gaps of surge protection devices
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Re-alignment of network poles
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Checking earth resistance of the grounding system at selected location of the network
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Checking and changing burned out conductors
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Repainting of metal structures if necessary
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B-
Transformers
Maintenance Schedule
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Duration
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Activity
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3-month period
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Transformer isolators cleaning
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Tightening of all MV/LV connectors
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Sept - Nov
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Checking transformer oil levels
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Tightening of all connections at protection devices
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Cleaning of LV compartment
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Checking earth resistance of the grounding system of neutral and carcass connections
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C-
LV lines Maintenance Schedule
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Duration
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Activity
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Regular basis
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Tightening of all LV connectors an service points
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Checking overhead line sags
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Re-alignment of network poles
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Checking earth resistance of the grounding system at selected location of the network
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Load balancing at the substation secondary
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Checking and reporting illegal connections
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Checking and changing burned out conductors
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Repainting of metal structures if necessary
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