Current limiting circuit breaker
US3946346A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1974 |
| Grant date | Mar 23, 1976 |
| Priority date | — |
| Expiry date | Apr 29, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H77/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor. An armature and armature pin are mounted for reciprocal movement when the electromagnet is energized. The armature pin is operatively connected to the auxiliary contact blades which are mounted for pivotal movement from a contact closed to a contact open position when the armature …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.