Download document () of 20
Clear selection
Download selection
We make what matters work*
Submit form in new Tab
Products
eaton-made-in-canada-primary-seal-reverse-red.png
Made in Canada >
Discover our deep Canadian roots.
Digital
Services
Markets
digital transformation
Markets
Customer success stories
Eaton helps 3E Power with an extensive distribution equipment lineup, 03/03/2022
Support
eaton-mississauga-building.jpg
Eaton Distributors
Locate a distributor in Canada
Company
MyEaton
Utility fuses

Capacitor fusing

Eaton’s Cooper Power series fuses are available in a wide variety of kV and amp ratings for use on both horizontal and vertical capacitor block bank configurations. The bus-mounted expulsion-type capacitor fuse provides highly reliable, economical protection for capacitor banks where medium energy-interrupting ability is required. In the event of a capacitor fault, excess current will flow through the fuse of the faulted unit. The NXC capacitor fuse is a current-limiting, non-expulsion, full-range clearing device. 

Contact me about this solution
Back to search
Expulsion design
Cost-effective
Current-limiting design
Increased fault current protection
Capacitor protection
Improved reliability

Core features

  • Greater latitude in capacitor bank design is now possible with the NXC outdoor, current-limiting capacitor fus
  • Wide variety of expulsion fuse kV and amp ratings for use on both horizontal and vertical capacitor block bank configurations
  • The expulsion fuse tube is constructed of bone-grade fibre overwrapped with epoxy-bonded filament-wound fibreglass or grade XX phenolic
  • Expulsion fuse ejector springs are engineered to control lateral motion of the fuse leader during ejection. If lateral motion is not controlled the leader can strike adjacent capacitor units resulting in unnecessary fuse operation and possible capacitor failures

Expulsion fusing for reliable capacitor bank protection

Cooper Power series expulsion fusing offers highly reliable, economic protection for capacitor banks where medium energy interrupting ability is required.

Providing smaller, economical protection options

The use of Eaton’s Cooper Power series X-Limiter fuse as a direct-connected capacitor fuse (particularly for indoor and/or enclosed banks), provides a full-range current-limiting fuse requiring a minimum of mounting space for a smaller low cost package. These units are bus-mounted or mounted directly on the capacitor busing to minimise space requirements and mounting cost. The fuse incorporates a high view operation indicator to quickly locate failed capacitor units.

NXC fuses for capacitor protection

Greater latitude in capacitor bank design is now possible with Cooper Power Series NXC outdoor, current-limiting capacitor fuses.
Specifications

Capacitor expulsion fuse electrical ratings

    Catalogue number
        
    Capacitor mounting configuration
     Power prequency interrupting rating (amps
Fuse max voltage rating (kV)
 Capacitor voltage rating (kV)
 Vertical
 Horizontal
 Current rating (amps)
 Interrupting rating (joules)
 Symmetrical
 Asymmetrical
8.7
 2.4 - 8.32
 FN 5B1**
   50
 10000
 7100
 10000
8.7
 2.4 - 8.32
 FN10B5
 FN13B3
 50
 15000
 3600
 5000
8.7
 2.4 - 8.32
 FN20B1
 FN19B1
 80
 15000
 3600
 5000
15
 9.96 - 15.2
 FN11B1***
 FN14B1*** 
 50
 15000
 3600
 5000
23
 19.92 - 21.6
 FN11B1***
 FN14B1***
 50
 15000
 1800
 2500
**FN5B1 is the only unit using tin-plated bronze: all others use aluminium
***Both FN11B1 and FB14B1 expulsion fuses are dual rated for 15 and 23 kV

Direct-connected capacitor fuse electrical characteristics

Fuse type
 Full-range
Maximum interrupting current
 50,000 A rms symmetrical

Direct-connected capacitor fuse recommended current ratings (Amperes)

Single-phase capacitor application recommendation
Capacitor voltage rating
 Fuse voltage rating (kV)
 50 kVAR
 100 kVAR
 150 kVAR
 200 kVAR
 300 kVAR
 400 kVAR
 500 kVAR
Fuse rating (A)
2400
 4.3
 35
 65
 100
 130*
 200*
 –
 –
2770
 35
 65
 100
 130*
 200*
 –
 –
4160
 18
 65
 65
 75
 130*
 150*
 200*
4800
 5.5
         125 (4) 
 125 (4)
 160 (4)* 
4800
 18
 40
 50
 65
 130*
 130*
 –
6640
 8.3
 12
 25 
 40
 50
 80
 100
 125 
7200
 12
 25 
 40
 50
 65
 100
 125 
7620
 12
 20
 30
 40
 65
 80
 100
7960
 10
 20
 30
 40
 65
 80
 100
8320
 10
 18
 30
 40
 65
 80
 100
9960
 15.5
 10
 18
 25
 40
 50
 65
 80
12470
 –
 12
 18
 25
 40
 50
 65
13280
 –
 12
 18
 25
 40
 50
 65
13800
 –
 12
 18
 25
 40
 50
 65
14400
 –
 12
 18
 25
 40
 50
 65
19920
 23.0
 –
 –
 12
 18
 25
 40
 40
21600
 –
 –
 12
 18
 25
 30
 40
1. All fuses meet “safe zone” tank rupture curves for medium voltage, Standard-Duty, Heavy-Duty, and Extreme-Duty capacitors or equal
2. Fuse application based on 150% of capacitor current
3. Fuses do not require derating for environment below 100 °C
4. Use 8.3 kV fuse
5. Asterisk (*) denotes parallel fuse assembly

NXC full-range current-limiting capacitor fusing recommendations

Capacitor or unit voltage rating
 Fuse voltage rating (kV)
 50 kVar*
 100 kVar
 150 kVar
 200 kVar
 300 kVar
 400 kVar
2400
 8.3
 30
 65
 90**
 –
 –
 – 
2770
 8.3
 25 
 65
 80**
 –
 –
 – 
4160
 8.3
 18
 40
 65
 65
 –
 – 
4800
 8.3
 18
 30
 45
 65
 –
 – 
6640
 8.3
 18
 25 
 40
 45
 65
 90**
7200
 8.3
 18
 25 
 30
 40
 65
 80** 
7620
 8.3
 18
 18
 30
 40
 65
 80** 
7960
 8.3
 18
 18
 30
 40
 65
 80** 
8320
 15.5
 10
 18
 25
 35
 50**
 70** 
9960
 15.5
 10
 18
 25
 30
 50**
 60**
12470
 15.5
 –
 12
 18
 25
 35
 50**
13280
 15.5
 –
 12
 18
 25
 35
 50**
13800
 15.5
 –
 10
 18
 25
 30
 50**
14400
 15.5
 –
 10
 18
 25
 30
 50**
19920
 23.0
 –
 12
 12
 18
 25
 36**
21600
 23.0
 –
 12
 12
 18
 25
 25
*For 50 kVar capacitors, it is difficult to choose reasonably sized fuses which will withstand the I2t outrush. This occurs due to the fact that I2t withstand goes down exponentially with fuse link rating rather than linearly. Consequently, the 50 kVar capacitor fusing recommendations only cover those units with voltages up to 9960 V
**Indicates 2 fuses in parallel
Download Links

Not finding the literature you need?

Visit this page for information on earlier models.

Additional literature

New to utility fusing?

Learn about the fundamentals of utility fuses

Learn more

Emergency and storm shipments

In the wake of a storm or disaster, Eaton understands that safety and speed of response is everything. You can rely on Eaton Care teams to plan, protect and connect.

Contact and process information
Eaton is an intelligent power management company dedicated to improving the quality of life and protecting the environment for people everywhere. We are guided by our commitment to do business right, to operate sustainably and to help our customers manage power ─ today and well into the future. By capitalizing on the global growth trends of electrification and digitalization, we’re accelerating the planet’s transition to renewable energy and helping to solve the world’s most urgent power management challenges.
SWE Toronto
Company
Quick links
© 2025 Eaton. All Rights Reserved.