| 1. |
Rated current of fuse to correspond
with selection schedule given by the manufactuer.
|
| 2. |
Fuse must withstand the transformer magnetizing
inrush current (10 Times transformer full load current
for 0.1 second).
|
| 3. |
Time current characteristic of high voltage fuse
must be located to the right of that of the low
voltage characteristic curve converted to the high
voltage side Any point of intersection between the
two curves may only occur where currents are higher
than the maximum short circuit current on the low
voltage side .
|
| 4. |
For melting times smaller than 0.1 second pre-arcing
l2t-values of high voltage fuse must be at least
50% higher than total operating l2t-value of low
voltage fuse.
|
| 5. |
Fuse shall withstand periodic overloads as specified
in ESI Standard 41/42.
|
| 6. |
It must be stressed that ”°over fusing”± of high
voltage fuse links may be dangerous!(This may cause
deterioration of high voltage fuse in case of short
circuits on the low voltage side).
|
| 7. |
For higher ambient temperatures or when fuses
are used in small enclosures derating factors have
to be considered.
|
| 8. |
For proper coordination between fuse and load
break switch IEC 420 publication has to be observed.
This means in brief that the time between triggering
of the striker pin and are extinguishing of the
melting element must not be higher than 50 milliseconds. |
