ABB VD4 12 - 10 Application of the Standards for X-Ray Emission; 11 Spare Parts and Accessories

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10. Application of the X-ray
emission Standards
One of the physical properties of vacuum insu-
lation is the possibility of X-ray emission when
the interrupter contacts are open.
The specific tests carried out at the PTB labora-
tories (Physikalisch-Technische Bundesanstalt,
in Brunswick - Germany) show that local emis-
sion at a distance of 10 cm from the interrupter
or pole surface, does not exceed 1 mSv/h.
It follows that:
– at the rated service voltage of vacuum inter-
rupters it is absolutely safe;
– application of the withstand voltage at indus-
trial frequency, according to the IEC 62271-
100 and VDE 0670 Standards, is safe;
– application of a voltage higher than the with-
stand voltage at industrial 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 phenom-
ena, with interrupters with open contacts, de-
pends on keeping the specific distance between
the contacts.
This condition is intrinsically guaranteed by
correct operation of the operating mechanism
and by adjustments of the transmission sys-
tem.
11. Spare parts and accesso-
ries
All assembly operations of spare parts/
accessories must be carried out
following the instructions enclosed with
the spare parts, by ABB personnel or
by suitably qualified customer person-
nel with in-depth knowledge of the
apparatus (IEC 60694) and all the Stan-
dards aimed at carrying out these
interventions in safe conditions).
Should the maintenance be carried out
by the customer’s personnel, respon-
sability for the interventions remains
with the customer.
Before carrying out any operation,
always make sure that the circuit-
breaker is open, the springs discharged
and that it is not supplied (medium
voltage circuit and auxiliary circuits).
To order circuit-breaker spare parts/accessories,
refer to the commercial ordering codes indicated
in the technical catalogue and always state the
following:
– type of circuit-breaker
– rated voltage of the circuit-breaker
– rated normal current of the circuit-breaker
– breaking capacity of the circuit-breaker
– serial number of the circuit-breaker
– rated voltage of any electrical accessories.
For availability and to order spare parts, please
contact our Service office.
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