ABB Power Distribution 5
Your safety first – always!
1 Summary
1.1 General
The vacuum circuit-breakers of type VD4 for 36 kV
rated voltage are intended for indoor installation in
air-insulated switchgear systems. Their switching
capacity is sufficient to handle any conditions
arising from switching of equipment and system
components under normal operating and fault
conditions, particularly short-circuits, within the
parameters of their technical data.
Vacuum circuit-breakers have particular ad-
vantages for use in networks where there is a high
switching frequency in the working current range
and/or where a certain number of short-circuit
breaking operations are expected. Type VD4
vacuum circuit-breakers are suitable for auto-
reclosing, and have exceptionally high operating
reliability and long life.
The vacuum circuit-breakers in column design are
intended for permanent mounting. These devices
also have trucks. Their basic structure is shown in
figures 3/1 to 3/3.
1.2 Standards and specifications
1.2.1 Switchgear manufacture
The switchgear complies with the following
specifications in accordance with DIN VDE/the
relevant IEC publications:
• VDE 0670, part 1000/IEC 60694.
1.2.2 Installation and operation
The relevant specifications are to be taken into
account during installation and operation, particu-
larly:
• DIN VDE 0101, Power installations exceeding
AC 1 kV
• VDE 0105, Operation of electrical installations
• DIN VDE 0141, Earthing systems for special
power installations with rated voltages above 1 kV
• Accident prevention regulations issued by the
appropriate professional bodies or comparable
organisations.
In Germany, these comprise the following safety
regulations:
– Health and Safety at Work Standards VBG 1
and VBG 4
• Safety guidelines for auxiliary and operating
materials
•
Order related details provided by ABB Calor Emag.
1.3 Operating conditions
1.3.1 Normal operating conditions
Design to VDE 0670, part 1000, "Common
specifications for high-voltage switchgear and
controlgear standards" and IEC publication 60694,
with the following limit values:
• Ambient temperature:
– Maximum:
•• Rated current 1250 A + 55 °C
•• Rated current 1600 A + 40 °C
•• Rated current 2000 A + 55 °C
•• Rated current 2500 A + 40 °C
– Minimum (according to
"minus 5 indoor class") – 5 °C
• Humidity:
– the average value of the relative
humidity, measured over a period
of 24 h, does not exceed 95 %
– the average value of the water
vapour pressure, over a period
of 24 h, does not exceed 2,2 kPa
– the average value of the
relative humidity, over aperiod
of one month, does not exceed 90 %
– the average value of the water
vapour pressure, over a period
of one month, does not exceed 1,8 kPa
• Maximum site altitude:
≤ 1000 m above sea level.
1.3.2 Special operating conditions
Special operating conditions are to be agreed on
by the manufacturer and user. The manufacturer
must be consulted in advance about each special
operating condition:
• Site altitude over 1000 m:
– Allow for the reduction in the dielectric
strength of the air.
• Increased ambient temperature:
– Current carrying capacity is reduced.
– Provide additional ventilation for heat
dissipation.
• Climate:
– Avoid the risk of corrosion or other damage
in areas:
•• with high humidity and/or
•• with major rapid temperature fluctuations.
– Implement preventive measures (e.g. electric
heaters) to preclude condensation pheno-
mena.
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