EFI — epoxy fault interrupter (one-shot interrupter) for 25.8 kV overhead lines
EFI is a one-shot fault interrupter with solid epoxy insulation and vacuum interrupters for 25.8 kV overhead lines. It breaks a fault current of up to 12.5 kA on a tap and isolates the faulted section without multi-shot auto-reclosing.
- Rated voltage
- 25.8 kV
- Rated current
- 400 A
- Breaking current
- up to 12.5 kA
- Short-time withstand current
- 12.5 kA, 1 s
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
EFI (Epoxy Fault Interrupter) works as a one-shot automatic circuit breaker on 25.8 kV overhead lines. It is installed on taps and separate line sections. EFI breaks a fault current of up to 12.5 kA once, protecting the network upstream. There is no multi-shot auto-reclosing as in a recloser, so for branches the device is cheaper. The model was developed in 2010, and type tests were carried out by KERI.
The drive is spring-operated. The arc is extinguished by vacuum interrupters embedded in epoxy bushings made of hydrophobic cycloaliphatic resin HCEP. The bushings keep their insulation in polluted areas, resist tracking, ultraviolet radiation and vandalism, and the creepage distance meets ANSI requirements. The tank and the control cabinet are stainless steel. There is no oil or SF6 in the device. Mechanical life is 10,000 operations without maintenance.
Rated voltage is 25.8 kV, rated current 400 A, frequency 50/60 Hz. Short-time withstand current is 12.5 kA for 1 s, making capacity 32.5 kA (peak). The control circuits are rated for 110–220 V AC or 24 V DC, test voltage 2 kV, impulse 6 kV. Temperature range is −25…+70 °C. From a fully charged battery the device performs 50 operations or runs for 24 hours without external power, and a separate protection prevents deep discharge of the battery.
Operation is manual and automatic with digital control. The overcurrent protection 50P, 50G, 51P, 51G has IEC and ANSI/IEEE curves and 37 non-standard characteristics, with inrush current blocking and indication of line current and voltage presence. The ETMFC610 controller with a built-in or separate RTU adds sectionalizing and communication functions. A simpler option is the digital relay ETMFC50 with functions 51 and 50, a sectionalizer, overload blocking, contact wear monitoring and programmable SCADA ports. A multifunction controller ETMFC101-N2 is also available for EFI.
KERI tested the device to the KEPCO specification for 25.8 kV polymer fault interrupters, and it complies with IEC 62271-111 and ANSI C37.60. EFI protects branches and consumer taps of overhead lines and works in distribution network automation systems.
Technical specifications
| Rated voltage | 25.8 kV |
|---|---|
| Rated current | 400 A |
| Breaking current | up to 12.5 kA |
| Short-time withstand current | 12.5 kA, 1 s |
| Making capacity | 32.5 kA (peak) |
| Drive | spring-operated |
| Service life | 10,000 mechanical operations without maintenance |
| Backup power | 50 operations or 24 h from the battery |
| Controller | ETMFC610 / ETMFC50 |
| Temperature | −25…+70 °C |
| Standards | KEPCO specification, IEC 62271-111, ANSI C37.60 |
Request a price and lead time
EFI — epoxy fault interrupter (one-shot interrupter) for 25.8 kV overhead lines. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 21 00 00 |
|---|---|
| HS, 6 digits | 8535 21 |
| CN (EU) | 8535 21 00 |
| HTSUS (USA) | 8535 21 00 00 |
| China customs tariff | 8535 21 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
How does EFI differ from a recloser?
EFI breaks a fault current of up to 12.5 kA once and does not perform multi-shot auto-reclosing. That is why it is installed on branches and taps of 25.8 kV overhead lines.
How long does the device work without external power?
A fully charged battery is rated for 50 operations or 24 hours of operation. The battery has deep discharge protection.
What protection functions does EFI have?
Overcurrent protection 50P, 50G, 51P, 51G with IEC and ANSI/IEEE curves and 37 non-standard characteristics. Inrush current blocking is provided.
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