G&W Electric Company
3500 W. 127th Street
Blue Island, IL 60406 USA
Tel: 708.388.5010
Fax: 708.388.0755
www.gwelec.com
ISO 9001:2008 Certified
ISO 14001:2004 Certified
G&W Fused Switch Information Sheet
Important information regarding G&W switches equipped with 21.1V dry well
fuse canisters
G&W switches can be equipped with 21.1kV rated air insulated, non-load break dry well fuse
canisters welded into an SF6 insulated tank. Switches can be equipped with a single fuse
canister per phase or two fuse canisters per phase connected in parallel. The information
below can be used for both of these switch types.



Continuous Current Ratings: The continuous current rating for each fuse canister, with
solid links (G&W part number A1952 0019 C00) installed in place of fuses, is 160A. The
current ratings provided by the fuse manufacturers assume the fuse canisters are
installed in oil. SF6 cannot transfer heat as efficiently as oil and, because of this, some
fuse designs may have their continuous current rating de-rated. The allowable
continuous current with the fuse installed in an SF6 insulated fuse canister is provided
for many commercially available fuses in the tables below.
Parallel Fuse Canisters: Designs with parallel fuse canisters are used for applications
where a higher continuous current is required. It is important to install fuses with the
same voltage and current ratings into each canister. Doing so will effectively double the
current rating per phase as compared to a switch equipped with one fuse canister per
phase.
Fuse Criteria: The following pages include a list of fuses that can be used with G&W
switches equipped with 21.1kV dry well fuse canisters. Other fuses are useable
provided they meet the criteria outlined below:
- Maximum fuse length: 17.21” to end of mounting stud
- Non-gassing type
- Non-indicator style fuses
- Nominal fuse diameter is 2.15” or less
- Stud on each end of fuse is .623” in diameter and 1” long
- Some fuse designs will have reduced current ratings because the fuse canister is
installed inside an SF6 insulated tank. The equation below can be used to
determine whether the fuse will have a reduced current rating.
𝐷𝑒 − 𝑅𝑎𝑡𝑒𝑑 𝐶𝑜𝑛𝑡𝑖𝑛𝑢𝑜𝑢𝑠 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝑜𝑓 𝑎 𝑓𝑢𝑠𝑒 = √
32 𝑊𝑎𝑡𝑡𝑠
1.5 𝑋 𝐹𝑢𝑠𝑒 𝑅𝑒𝑠𝑖𝑠𝑡𝑎𝑛𝑐𝑒
The continuous current of the fuse installed in an SF6 insulated fuse canister is
the lesser of the current rating of the fuse or the result of the above equation.
2
The fuse resistance in the above equation must come from the fuse
manufacturer.

Explanation of the notes used in the tables below
Note 1: Each fuse has a range of resistances considered acceptable by the
manufacturer. The range of de-rated continuous current in the tables below is
calculated from this resistance range. The fuse’s actual de-rating can be
determined by using the equation above and measuring its resistance in ohms.
Note 2: G&W switches can be equipped with one fuse canister per phase or two
(parallel) fuse canisters per phase. Designs with parallel fuse canisters are used
for applications where a higher continuous current is required.
Note 3: G&W switches can be equipped with one fuse canister per phase or two
(parallel) fuse canisters per phase. Designs with parallel fuse canisters are used
for applications where a higher continuous current is required. Each fuse has a
range of resistances considered acceptable by the manufacturer. The range of
de-rated continuous current in the tables below is calculated from this resistance
range. The fuse’s actual de-rating can be determined by using the equation
above and measuring its resistance in ohms.
Cooper Power Systems Fuses for G&W 21.1kV rated fuse canisters
Maximum
Voltage
Fuse
Type
ELX
23kV
NX
Catalog Number
Factory
labeled
current Rating
(Amps)
Approximate De
Rated Continuous
Current (Amps)
3565003M11M
3
No De Rating required
3565006M11M
6
No De Rating required
3565008M11M
8
No De Rating required
3565012M11M
10
No De Rating required
3565010M11M
12
No De Rating required
3565018M11M
18
No De Rating required
3565020M11M
20
19-20
1
3565025M11M
25
20-24
1
3565030M11M
30
27-30
1
3565040M11M
40
27-31
1
(2) 3565025M11M installed in parallel
50 (both fuses)
40-48 (both fuses)
3
(2) 3565030M11M installed in parallel
60 (both fuses)
54-60 (both fuses)
3
(2) 3565040M11M installed in parallel
80 (both fuses)
54-62 (both fuses)
3
FA5H6
6
No De Rating required
FA5H8
8
No De Rating required
FA5H10
10
No De Rating required
FA5H12
12
No De Rating required
FA5H18
18
14-16
1
FA5H20
20
15-17
1
Notes
3
X-Limiter
FA5H25
25
19-22
1
FA5H30
30
22-26
1
FA5H40
40
27-31
1
(2) FA5H25 installed in parallel
50 (both fuses)
38-44 (both fuses)
3
(2) FA5H30 installed in parallel
60 (both fuses)
44-52 (both fuses)
3
(2) FA5H40 installed in parallel
80 (both fuses)
54-62 (both fuses)
3
23F003-I
3
No De Rating required
23F006-I
6
No De Rating required
23F008-I
8
No De Rating required
23F010-I
10
No De Rating required
23F012-I
12
No De Rating required
23F018-I
18
16-18
1
23F020-I
20
16-18
1
23F025-I
25
20-22
1
23F030-I
30
23-26
1
23F040-I
40
28-31
1
23F050-DW
50
28-31
1
(2) 23F025-I installed in parallel
50 (both fuses)
40-44 (both fuses)
3
(2) 23F030-I installed in parallel
60 (both fuses)
46-52 (both fuses)
3
(2) 23F040-I installed in parallel
80 (both fuses)
56-62 (both fuses)
3
(2) 23F050-DW installed in parallel
100 (both fuses)
56-62 (both fuses)
3
Thomas and Betts Fuses for G&W 21.1kV rated fuse canisters
Rated
Max
Factory labeled
Fuse
Voltage
current Rating
Type
(kV)
Catalog Number
(Amps)
Approximate DeRated Continuous
Current (Amps)
HTFX250006
6
No De Rating required
HTFX250008
8
No De Rating required
HTFX250010
10
No De Rating required
HTFX250012
12
No De Rating required
HTFX250018
18
No De Rating required
HTFX250020
20
19-20
1
HTFX250025
25
24-25
1
HTFX250030
30
25-28
1
HTFX250040
40
29-32
1
HTFX250050
50
32-35
1
(2) HTFX250030 installed in parallel
60 (both fuses)
50-56 (both fuses)
3
(2) HTFX250040 installed in parallel
80 (both fuses)
58-64 (both fuses)
3
(2) HTFX250050 installed in parallel
100 (both fuses)
64-70 (both fuses)
3
FX
23
Notes