abb
SafeLink
SF
6
Insulated Ring Main Unit
Installation and Operating Instructions
SLMIO ver 2.12
ABB Ltd, Switchgear Division, Auckland, New Zealand
10
2.4 Fuse Link Selection
Fuse links must have a barrel length of 292mm and dimensional compliance to
DIN 43625. Fuse links are to comply to IEC 60282-1 with ‘medium’ striker energy, e.g.
ABB CEF range or equivalent.
The SafeLink has been heat run tested to IEC 60298 under two conditions: with 400A
and 630A maximum ring circuit currents. Under these conditions the maximum
continuous heat dissipation from each fuse canister is 58W and 47W respectively.
The table below, based on ABB CEF backup fuses, gives maximum continuous fuse
current values which are valid for ambient temperatures up to 40°C. Fuse links from
other manufacturers may have markedly different heat generation figures. Where
SafeLink is installed in high ambient temperature environments (over 40°C) please seek
further advice from your local ABB agent; this may apply where the unit is installed in
a padmount enclosure or similar.
Ring current of 400A
Ring current of 630A
Fuse Link
Rating (A)
Fuse Power
Loss (W)
Max. Current (A), 58W Max. Current (A), 47W
16
32
16
16
25
47
25
25
40
52
40
39
63
78
57
52
80
82
71
65
100
103
78
71
125
*
125
85
79
*
Switch-fuse combination not covered by IEC 60420 type-test certificate for fuse links
greater than 100A.
For example:
If a 1000kVA, transformer with full load current of 52A is to be protected in an 11 kV,
630A ring circuit. Then a 63A fuse link can be used. Alternatively if a 130% overload
of the transformer is required, then a 100A fuse link should be selected.
The figures quoted below are reproduced from the ABB CEF catalogue for line voltages
of 10-12 kV.
Transformer
Rating (kVA)
100-
125
160
200-
250
315
400
500
630-
800
1000
1250
1500
Fuse Link (A)
16
16-25
25
25-40
40
40-63
63
63-80
80-100
100