The trend towards higher system voltage, increased load density, and larger substations has caused higher fault current potentials on the distribution system and the need to interrupt those higher currents when a fault exists. Current-limiting fusing provides both a high interrupting current rating and limits the peak value of current and the amount of energy to within acceptable levels for protection of the transformer.

Improved Design

Housing – The  dry-well  housing  consists  of  filament-wound  glass  tubing  with  a  resin-rich  outer. This outer surface serves as the barrier against oil permeation through the tubing wall.  

Dry-well fuseholder location – In padmounted transformer applications, the dry-well fuseholder is mounted on the transformer front plate, below the oil level. Because the current-limiting fuses that these fuse-holders are designed to accept will not function properly if exposed to transformer oil, the interior of the fuseholder must remain oil tight.

ECI manufactures two types of dry well fuse holders:

• Non-load break for use with both single and three phase padmount applications.
• Non-load break for use with both single and three phase submersible applications.