A new generation of dead tank circuit breakers

With a proven track record

Features & Benefits

  • Reduced life-time costs
  • Minimal maintenance required
  • Small footprint for distribution breakers from 25.8 kV and above
  • Internal arc tested in compliance with IEC 60298 featuring accessibility class A. Test has been performed with low voltage door in open and close position to ensure maximum operator protection
  • Out-of-phase switching for a decentralized generation (windfarms)
  • Suitable for high-speed auto-recloser switching
  • Suitable for capacitor bank switching Class C2 (Recommended for capacitor Bank switching).
  • ANSI/IEEE “rain tested” enclosure (ANSI/IEEE C37.20.2)
  • Polymer bushing with creepage distance of more than 31.5mm/kV
  • Build with 3 highly reliable vacuum interrupter assemblies mounted inside the SF6 filled tank
  • Moderate and high seismic qualification (zone 1 – 4)

If the name sounds familiar, it’s normal. The VOX has been commercialised for more than two decades by Areva and Schneider Electric.

VOX, medium voltage dead-tank outdoor breaker

We, at CO7 Technologies, purchased the intellectual properties and assets for the VOX. The intent for us is to focus our efforts in developing and expending the VOX family. In January 2021, we will then move the production line from Schneider, Germany to our state-of-the-art facility in Montreal.

VOX combines the best new and proven technology for outdoor distribution applications up to 38 kV.


CO7 Technologies’ latest range of vacuum interrupters are housed in a fully welded, sealed-for-life, stainless steel tank, providing a controlled gas insulated environment totally immune from external ambient conditions. A spring charged mechanism provides manual or motorized circuit breaker operation.


VOX has been designed and tested to meet the requirements of the relevant applicable IEC, BS, AS, ANSI, IEEE, GOST and GB standards.

Technical Characteristics

Technical characteristics IEC/BS/AS ANSI GOST/GB
Rated maximun voltage kV 36 38 40.5
Rated impulse withstand voltage kVp 170/200 200
(258 kVp
chopped wave)
Power frequency withstand voltage kV 70/80/95 80 95
Rated continuous current
Rated withstand current (3s)
Rated arc fault containment
1 200 / 2 000
25 / 31.5 / 40
25-1s / 31.5-0.5s
Rated short circuit breaking current
Closing and latching capability
25 / 31.5 / 40
65 / 82 / 100
Operating sequence OCO-15s-CO (IEC)
O-0.3s-CO-15s-CO (ANSI)
Number of operations at rated current
Number of operations at short circuit current
10 000
Gas fill pressure bar 0.5
Control voltage Vdc
24,48,125, 250
Operating temperature range °C - 40 to + 40 (option - 60 to + 55)
Relative humidity % 0-100
Altitude (maximum for quoted ratings) ft/m 10,000 / 3,000
Seismic withstand g 0.5

Optional equipment and custom solutions

  • Accommodation for additional current transformers
  • Gas density monitoring
  • Surge arresters
  • Recloser configuration with auxiliary voltage transformer and protection relay
  • All-in-one solution with disconnectors, earthing switch, VT’s, CT’s, SA…