Fuses 2019-01-21T08:00:00+00:00

Power Fuse (Expulsion Type)

Features

◆ For protection of substation facility and extra-high voltage distribution line
◆ Suitable when COS and current limiting fuse is used/not used
◆ When station type power fuse is used, prevents accidents due to Arc/gas emission

This product is equipped with an excellent fuse unit in which the usable body is made up of nicke-chrome or silver wire. Therefore, its time-current characteristic is semi-permanently accurate, which makes it a reliable choice. It is also a perfect damage protection equipment that can interrupt fault current through its highly stable and sturdy fuse mouting.

  • For protection of extra-high voltage distribution line and cable
  • For protection of high-capacity transformer and MOF
  • For protection of phase compensation condenser bank
  • For use as backup fuse for cutout switch
  • When surge current-susceptible current limiting fuse cannot be used
  • When cooperative operation and protection with other over-current protective equipment is difficult.
  • When use of current limiting fuse cannot be used due to the environment, difficulties in installation or handling.
Inquiry

Ratings

Type JFM-20(Indoor) JFD-20(Outdoor) SM-40(Indoor) SMD-40(Outdoor)
Opening style Station Drop-out Station
Fuse JEU-20 1K~200K SMU-40 *300E~400E
Ratings kV Nom. 25.8 25
Max. Des. 27 29
BIL 125 150
Ampere (rms) Max. 200K 400E
Interrupting Sym 12,500 20,000
Asym 20,000 32,000

* American S&c product
* The specification of this product may be altered without prior warning in order to improve its quality.

Reference data

Application Standard(Rated uninterrupted current and selection of current)
The following has to be considered when selecting a rated current for a current fuse.

  • Should not operate in the estimated over-current(Fuse unit must fuse within 300s in 200~240% level of the rated current)
  • Should not operate in transient surge current(Fuse unit must withstand 10 times the full-load current of a transformer for more than 0.1s)
  • Cooperation with other protective equipmentWhen installing a current fuse indoors, it is advisable to use a model with a silencer.

Transformers protection fuse application guide

Transformer rated capacity (kVA) Transformer rated full-load current
In[A]
Transformer exiting/inrush current
If=10ln
Symmetrical fault current Virtual value Is=[A] 100ln/%Z Range of fuse rated selection
Minimum Maximum
5 0.13 1.3 2.10 1K 3K
7.5 0.19 1.9 3.15 1K 3K
10 0.25 2.5 4.2 1K 3K
5 15 0.38 3.8 6.3 1K 3K
6.67 20 0.50 5.0 8.4 1K 3K
10 30 0.76 7.6 12.6 1K 3K
15 45 1.13 11.3 18.9 3K 6K
25 75 1.89 18.9 31.5 3K 6K
33 100 2.52 25.2 42.0 3K 6K
50 150 3.78 37.8 63.0 6K 6K
67 200 5.04 50.4 84.0 8K 10K
75 225 5.67 56.7 94.5 8K 10K
100 300 7.56 75.6 126.1 10K 12K
167 500 12.6 126 210.1 15K 20K
250 750 18.9 189 315.1 25K 30K
333 1,000 25.2 252 420.2 30K 40K
500 1,500 37.8 378 630.3 50K 65K
667 2,000 50.4 504 840.4 65K 80K
1,000 3,000 75.6 756 1,260.6 100K 140K
1,333 4,000 100.8 1,008 1,680.8 140K 200K
1,667 5,000 126.0 1,260 2,101.0 200K 300E
2,000 6,000 151.2 1,512 2,521.2 200K 300E
2,500 7,000 189.0 1,890 3,151.5 300E 400E
3,333 10,000 252.0 2,520 4,202.0 300E 400E

Considering the electric/mechanical characteristics of power fuse (current fuse), it is advised to use a fuse unit that is manufactured by the same company.