Compact dimensions, direct current paths, double-knife construction and cast resin insulators are common to all OJON -type disconnectors.
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| Ratings | |
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| Rated voltage (kV) | 1 - 24 |
| Normal current (A) | 630 - 4000 |
The high short-circuit strength of these disconnectors is a result of these features. Contact pressure is achieved by spiral springs which compress the knives.
Silver-plating prevents the contact area of the contact and knives from ageing, and keeps the temperature rise within the limits set by the standards.
Owing to the double-knife construction, forces needed to operate the disconnectors remain moderate even at high rated currents.
The contacts of the disconnectors are made of copper bar for 630 A and of cast copper for 1000 - 4000 A.
The disconnectors may be connected to copper or aluminium busbars.