High voltage is generally identified as voltages upwards of 15001 volts, includes equipment such as oil circuit breakers, vacuum circuit breakers, SF6 circuit breakers, grounding switches along with their related metering and control components.

ESI performs various services to equipment of this type. These services include complete re-manufacturing, retrofitting, field conversions, retro-filling, upgrading and match and line up switchgear projects, as well as the supply of new, discontinued, or obsolete equipment.