VD4/R - VD4/L - VD4/R-SEC - VD4/L-SEC
- INSTALLATION AND OPERATING INSTRUCTIONS
30
—
10. Application of the X-ray emission Standards
One of the physical properties of vacuum
insulation is that Xrays could be emitted when the
interrupter contacts are open.
The specific tests conducted at the PTB
laboratories (Physikalisch-Technische
Bundesanstalt, in Brunswick - Germany) show that
local emission at a distance of 10 cm from the
interrupter or pole surface, does not exceed
1 μSv/h.
This means that:
•
use of vacuum interrupters is absolutely safe at
the rated service voltage;
•
application of the withstand voltage at power
frequency, according to the IEC 62271-100 and
VDE 0670 Standards, is safe;
•
application of a voltage higher than the
withstand voltage at power frequency or of a
test voltage in direct current, specified in the
IEC and VDE Standards, cannot be used;
•
limitation of the above-mentioned local
phenomena, with interrupters with open
contacts, depends on maintaining the specific
distance between the contacts.
This condition is intrinsically guaranteed by
correct operation of the operating mechanism
and by the adjustments of the transmission
system.
