Interrupter Overview

Standard Arcing Horn

High-speed, snap-out arcing horns are standard equipment on all transmission switching applications.  Fabricated from beryllium tube, the rod is tapered to achieve high tip speed during the first cycle after separation.  A black neoprene snubber  attached to two stainless steel support rods is provided to prevent recoil into the open gap during operation.  A copper hook acts as a catcher for the arcing horn during opening, allowing a suitable open gap to be developed before the horn releases with great speed.

Standard arcing horns are suitable for interruption of limited amounts of line charging and transformer magnetizing currents.  In performance, this horn is comparable to horns offered by other manufacturers.

High Velocity Whip

For interruption of substantially greater amounts of line charging current, SEECO has developed the High Velocity Whip (HVW), a spring loaded, stored energy arcing horn, which achieves a very large air gap within the first cycle after separation. The whip also employs a Delrin® tip, which assists in the dissipation of ionized gases.  Tested at NEETRAC, the HVW outperformed all other arcing horns in head to head competition.

The HVW is available for use with all SEECO side, center, center Vee and double end break switch configurations, at voltage ratings of 46-230 kV.

Single Bottle Interrupter

SEECO manufactures a single bottle interrupter for those applications where the recovery voltage does not exceed 30 kV peak and the maximum interrupting current is 3000 amps or less.  Less expensive than multi bottle interrupters, single bottle devices offer substantial cost savings but with reduced functionality and more limited switching applications.  An off-setting disadvantage can be the occasional confusion experienced by field personnel who often struggle with understanding the limitations of the single bottle device relative to the broader functionality of the multi bottle interrupter.   Single bottle interrupters can be installed initially with the switch or added later as a field retrofit or upgrade.

Common switching applications for single bottle interrupters include:

• Load dropping – 70% pf of load interruption up to 25 kV on ungrounded systems and 34.5 kV on solidly grounded systems
• Line dropping – to 25 kV or 72.5 kV with voltage limiter
• Loop splitting (parallel break) – to 230 kV if recovery voltage does not exceed 30 kV peak

This interrupter can be used with both SEECO and non-SEECO group operated switches, including side-break, center-break, center Vee and vertical-break configurations.  Please refer to product catalog section PC-007-02 and this webpage for additional information.

For two and three-way phase-over-phase switching applications, SEECO offers a single bottle interrupter that is shared by all ways of the switch.  Like the multi bottle interrupter below, the cost of the interrupter unit is spread across each way of the switch, making the cost ‘per way’ progressively less expensive; all ways of the switch participate in the full functionality of the device.  Please refer to product catalog section PC-007-01 and this webpage for additional information.

Multi Bottle Vacuum Interrupter

For maximum sectionalizing flexibility, SEECO manufactures multi-bottle vacuum interrupters that provide a broader range of interrupting capability, including load dropping, line dropping and loop splitting.  Multi-bottle interrupters simplify switching “rules” and reduce the confusion frequently experienced by operating personnel over the capability (device rating) and appropriate use of more limited devices.  Multi bottle interrupters can be installed initially with the switch or added later as a field retrofit or upgrade.

In transmission sectionalizing applications, the use of (multi bottle) interrupter switches helps extend the operating life of more expensive circuit breakers by reducing unnecessary operations and wear, allowing breakers to be reserved for their intended duty of fault interruption.  On a cost per operation basis, interrupter switches are substantially more economical and better suited for general line sectionalizing purposes.

When used in conjunction with two and three-way switches, the benefits of multi-bottle interrupter devices are significant.  One interrupter unit (column) is used per phase and is mounted on the stationary, non-rotating insulator; the interrupter unit is then shared by each way of the switch.  The shared interrupter increases the cost savings achieved by utilizing two and three-way switches and magnifies the ‘bundling’ effect.

Upright (vertical) Mounting

For two and three-way switches of any voltage and one-way switches rated 115 kV and up, the interrupter column is always mounted upright (vertical).  For one-way switches rated 46-69 kV, the interrupter column can be mounted either upright or cantilever.  For additional information on multi bottle devices mounted upright, please refer to product catalog section PC-007-01 and this webpage.

Cantilever (horizontal) Mounting

For SEECO one-way, phase-over-phase switches rated 46-115 kV, the interrupter column can be mounted cantilever which permits more compact phase spacing, reducing pole height and cost.  Cantilever mounting of the interrupter is not available on two and three-way switches, and on one-way switches rated 138 kV and up.  For additional information on multi bottle devices mounted cantilever, please refer to product catalog section PC-007-04 and this webpage.

Vertical Break Mounting

SEECO type VM multi bottle interrupters can also be supplied with SEECO vertical break switches as well as those offered by other manufacturers, with voltage ranges of 46-230 kV and current interruption ratings through 3000 amps.  For additional information on multi bottle devices mounted on vertical break switches, please refer to product catalog section PC-007-03 and this webpage.

Brand Compatibility

In response to very strong interest from our customers and the general market, SEECO has begun adaptation of our existing single and multi bottle interrupter products for use with other brands of group operated switches.  It is our intent to eventually offer vacuum interrupter devices for all major brands and switch configurations.  SEECO is currently working closely with Pascor Atlantic, USCO and Royal Switchgear.  Interrupter kits will also be developed for Southern States, S&C, Pascor, Turner and others as they are requested by customers.

For general questions about SEECO interrupters and compatibility with other brands and configurations of group operated switches, please contact the factory or your local SEECO representative.