Home/ Case Studies/ Distribution Network

Pole-Mounted Switchgear Metering

Three-phase combined current transformers fitted to pole-mounted switch assemblies on a medium-voltage feeder.

Pole-mounted switchgear and instrument transformers silhouetted against a dusk sky
Distribution Network

An industrial park feeder used pole-mounted reclosers with no metering at all. The operator wanted revenue metering and protection on the same assembly, without extending the outage or rebuilding the poles.

The challenge

The recloser bushings were the only mounting point available, and the switch enclosures left almost no room for a separate zero-sequence transformer. Any new hardware had to bolt onto the existing bushings and work within the tight clearances of the existing poles.

Our solution

We supplied three-phase combined current transformers designed to mount on the recloser bushings, providing metering, protection and zero-sequence functions from one compact unit. Each unit was vacuum-cast in epoxy with an integrated mounting collar matched to the bushing dimensions.

Products supplied

Three-phase combined current transformers for ZW-series pole-mounted reclosers, with 0.5S metering cores, 10P10 protection cores and zero-sequence output, plus secondary wiring kits and terminal enclosures.

Outcome

The feeders now bill accurately and trip selectively on phase and earth faults. Installation was completed within the scheduled outage, and the operator has ordered the same configuration for two further feeders.

Need help specifying a unit?

Our engineers can recommend the right accuracy class, ratio and insulation type for your site.