Current transformer secondary voltage limiter
US4538202A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 1984 |
| Grant date | Aug 27, 1985 |
| Priority date | — |
| Expiry date | Feb 23, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T1/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for protecting the secondary winding of a current transformer against destructive or dangerous overvoltages when connected across the secondary, has a transparent tubular casing with a stud support and conductive stud within one end. The stud is threadably mounted in the stud support so it can be adjusted longitudinally and it has an arcing surface on its inner end. Within the other end a support member carries a longitudinally sliding conductive plunger. The plunger is biased inwardly towards the arcing surface of the stud but it is restrained from inward movement by a fusible element which engages it and restrains it. The fusible element forms another arcing surface spaced a predetermined distance from the arcing surface on the stud. One terminal is provided on the outer end of the conductive stud and another on the outer end of the support member connected to the plunger by a flexible braid. A small overvoltage of short duration causes an arc current to flow to limit the voltage. An overvoltage of longer duration fuses the fusible element allowing the plunger to move inwardly to short the terminals and the secondary windings. If desired an auxiliary contact arrangement …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.