28
Current transformer data
The current transformer has a ratio of
800 A:1 A. The accuracy is 0.5 VA 5P20 to IEC
60044-1.
Voltage sensor data (optional)
The ratio of the voltage sensors is adapted to
operation with the control and protection
relay and provides a 110 V/√3 secondary
signal when the recloser is energized at rated
maximum voltage.
Ambient conditions
The type SDR vacuum recloser is suitable for
use under “usual service conditions” as given
in IEEE standard C37.60/
IEC 62271-111, as follows:
Ambient temperature -40° C to 55° C
Solar radiation <1,120 W/m
2
Altitude <1,000 m or less
Altitude correction factor
The insulating capability of insulation in air
decreases as the altitude increases due to the
reduced air density. The rated lightning
impulse withstand voltage values (see Table
5) are valid according to IEC 62271-1 and
IEEE C37.60 up to an installation height of
1,000 m above sea level. Above a height of
1,000 m, the insulation level must be
corrected in line with Figure 29.
Example:
At 2,500 m altitude, a unit rated
110 kV BIL under “usual service conditions”
will have a lightning impulse withstand
capability of:
110
K
=
110
e
m(h-1000)/8150
=
110
1.2
= 91.5 kV
Table 9: Power consumption
Auxiliary system
Unit
Power consumption
Auxiliary power requirement, controller
W
<15, typically <10
Auxiliary power requirements, heating
(controller and switch unit)
W
Control cubicle = 37.5,
switch unit = 50
Auxiliary power requirement, communication
(dependent on modem or radio used)
W
<15 typical
External requirements
(external user, for instance, laptop)
A
2 (if supplied by auxiliary transformer);
10 (if connection to low-voltage network)
Figure 29: Altitude correction factor
K
U ≥ U0 x K
U Rated withstand voltage U under standard
reference atmospheric conditions
U0 Required rated withstand voltage for the
installation location
K Altitude correction factor K = e
m (h-1000)/8150
H Installation height in meters
m 1.0 for alternating-current voltage, lightning
impulse voltage (among the conductors,
conductor-ground, longitudinal stress)
1.5
1.4
1.3
1.2
1.1
1.0
1.0 1.5
2.0
2.5
3.0
3.5
4.0
Altitude cor
rection fact
or
Site altitude in thousands of meters
Summary of Contents for SDR 15.5 kV
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