IG-284-EN version 03; 06/05/2020
52
Recommended sequence
of operations
General Instructions
cgm
.800: Medium-voltage switchgear with integrated insulation in SF
6
gas
up to 36 kV in accordance with IEC Standard with rated current up to 800 A
5.6.1. Selection of recommended fuses
The fuses recommended for use in the fuse protection
functional unit are defined according to tests carried
out by the manufacturers. The following table shows the
recommended fuse ratings according to the U
r
/P
transf.
ratio:
U
r
network
[kV]
U
r
cubicle
[kV]
Ur
fuse
[kV]
Rated power of the transformer WITHOUT OVERLOAD [kVA]
25 50 75 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000
Rated fuse current (A) IEC 60282-1
10
24
6/12*
6.3 10
16
16
20
20
25
31.5
40
50
63
63 80*** 100*** 125*** 200***
-
13.5
24
10/24** 6.3 6.3
10
16
16
20
20
25
31.5
40
50
63
63
80*** 80***
-
-
15
24
10/24** 6.3 6.3
10
16
16
16
20
20
25
31.5
40
50
63
80*** 80*** 125***
-
20
24
10/24** 6.3 6.3 6.3
10
16
16
16
20
20
25
31.5
40
50
50
63
80*** 100***
* Fuses measuring 292 mm long.
** Fuses measuring 537 mm long. For fuses measuring 442 mm long, check with
Ormazabal
.
*** For cubicles with associated fuses
Table 5.1.
Fuse calibres for 24 kV cubicles
U
r
[kV]
Transformer rated power [kVA]
Network
Cubicle 100 125 160 200 250 315 400 500
630
800
1000 1250 1600 2000
Rated fuse current (A) IEC 60282-1
25
36
6.3
10
16
16
16
20
20
31.5
31.5
40
40
50
63
80
30
36
6.3
6.3
10
16
16
16
20
20
31.5
31.5
40
40
63
63
Table 5.1.
Fuse calibres for 36 kV cubicles
Considerations:
• General operating conditions: without overload and
temperature < 40 ºC.
• The values marked with an (*) correspond to SSK-type
fuses.
• Recommended fuses: SIBA 20/36 kV, HHD type, medium
type striker, for functional units up to 36 kV (according
to IEC 60282-1).
• For other makes and overcharge protection, check with
Ormazabal
.
• If any of the fuses blows, we recommend changing all
three.
• Temperature-rise testing of the fuse switch assembly,
according to IEC 62271-105.
Transfer currents according to IEC 62271-105:
The transfer currents have been tested in accordance with
the following parameters:
Ur fuse
[kV]
U
r
cubicle
[kV]
I
r
fuse
[A]
I
transfer
[A]
36
36
Type SSK 80
820
Table 5.2.
Transfer currents
Summary of Contents for velatia cgm.800
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