Introduction
Prevention and minimization of distribution network faults impact on users
Network voltage
Conditions for safe electricity
consumption
Characteristics
of safe products
Recommendations when buying electrical
appliances
Introduction
Electricity is generated in power stations according
to prescribed quality standards in force and then is transferred through
transmission and distribution networks to end-users. A series of external factors usually influences the quality of supplied electricity.
Such factors include:
- Atmospheric conditions (for example lightning);
- Consequences due to use of specific electricity units (electronic adjusters supplying blocks of electricity units and other);
- Manipulations in the energy supply network;
- Activation of protection and automated units, produced in view of decreasing network faults;
- Frequent switching on and off of big customers.
The above mentioned factors may cause:
- Variations in supplied voltage (impulse
voltage, drop in
voltage and power cuts).
Note:
In order to avoid damages to electricity units caused by hit of lightning, we recommend to equip both internal and external new electricity distribution installations with protection from impulse over-tension. We do as well recommend to switch off units from supply network in cases of active lightning activity.
- Curve voltage disturbance;
- Non-symmetrical supply of electricity.
Prevention and minimization of distribution network failures impact on users
In case of faults on the distribution network our main concern is to limit the impact of unforeseeable conditions to end-user as much as possible. There are many automated systems (for example systems for switching off) and protective units, serving to locate the fault and switch off the defaulting place from the distribution network
as soon as possible, so that only the defaulting part of the network remains without electricity supply. According
to the provisions set forth
in the General Terms and Conditions for Sale of Electricity of, the company may temporarily discontinue the supply of electricity, without previous notice to users, in case of:
- Prevention of immediate danger for the health and security of people, property and equipment;
- Failures in the electricity network or equipment, which are caused by
reasons beyond the control of the electricity distribution company;
- Finding out a non-coordinated change in the connection
diagram of users;
- In case of using electricity which is not accounted or
measured, be it partially or in total, by meters,
as well as in case of finding incorrect measurement;
- Where users fail to provide compulsory engineering conditions for installation of own source for reserve supply, where such conditions are prescribed by
the Supplier (in such cases Supplier shall not be liable for any damages caused –
please refer to General Terms and Conditions for Sale of Electricity);
E.ON Bulgaria sells electricity
to customers with nominal
voltage and with quality specifications adopted by the State
Energy and Water Regulation Commission, with
compulsory indicators concerning level of
reliability of supply, as defined by the Minister
of Energy and Energy Resources and with power and category of security of
electrical supply in accordance with the connection contract and its implementation.
Network voltage
Deviations from ideal characteristics of network voltage are due mostly to
the qualities of corresponding electricity customers. In order to limit such
influences our company has established constant control over the network and
undertakes follow-up engineering corrections.
Units with three phases or units with higher requirements to electricity
quality may be connected only provided that they are protected with suitable
engineering equipment designed with view to limiting the negative impact of
the following effects:
- Presence of supply
voltage only in one of the phases in three phase supply network;
- Fluctuations in
voltage;
- Changes in frequency.
The following units are extremely sensitive to sudden increase in
voltage:
Computers, control units, audio and video equipment, light adjusters, video
units, satellite receivers, fax machines, etc.
The following electricity consumption units are significantly sensitive to low tension:
Fridges, washing machines, etc.
Where you need to use units and installations which need better quality of electricity than supplied (especially concerning increase of tension), we recommend that before purchase you check with the supplier of specific unit for its sensitivity and stability, as well as
potential protective measures.
Conditions for safe electricity consumption:
- 1. When using safe connection corresponding to the standards and equipment
meeting safety requirements, the electricity supplied shall allow for the
operation of many units without posing a risk to health and property.
- Repair and maintenance of installations and units, including flexible and extension connections should be assigned only to
a specialized company.
- Please protect units and installations from people with limited ability to recognize dangers (children, mentally handicapped persons and similar), by placing protective covers on plugs. Pets should be protected as well from electricity caused damages.
- Purchase and switch on only safe units.
- Use the units only in accordance with their purpose and their
use manuals.
- Electrical appliances and connection cables should be protected in a
suitable way. The protection should correspond to engineering standards in
force. The standard protective elements of installations are not suitable for
appliances with higher requirements to electricity quality.
- You should not change
fuses with such intended for other application,
nor repair them
yourselves.
You may by such
actions expose at risk your life and the life of other people.
- ATTENTION!
When passing through human body electricity may cause harm or death. Observe all recommendations listed above strictly.
Safe products characteristics
- The product must be complete. Neither package, nor control items must be missing, damaged or loose.
- Flexible and extension cables must correspond to established standards. Never use hand made extensions!
- No part of the product must be damaged by heat, sharp objects, chemical
aggressive materials and other, which may harm insulation;
- The product’s electrical parts must not interfere or have contact with water,
except in case where according to the producer instruction their purpose is
such.
- You must be sure that conductors are not overloaded and that wires are checked regularly.
Recommendations when buying electricity consuming units
- You must make sure that:
- The appliance label contains explicit mention of operative voltage of 220 V (230 V) or 220/380 V (230/400 V) and 50 Hz;
- The label of the appliance must indicate details of the producer (name
or trade mark);
- On the label of the appliance there must be a notice of conformity with
European standards;
- Producer supplies the appliance with plug. If not, connection must be undertaken by specialized company.
- Keep all documents concerning purchase, connection and maintenance of unit and connectors.
What you should do if you find out or suspect problems in electricity supply
- If the appliance is not operating according your expectations, the cause may not be electricity related fault. Check connection and usage by consulting the instruction for appliance use.
- If however your unit is not operating, check if other appliances are not operative. If you consider that the appliance is defective, please consult specialized service office for the appliance. Do not repair the appliance or the installation by yourself.
- If the appliance and the wires are operating normally, please contact us. (refer to section Contacts).
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