Current limiting circuit breaker
US4071836A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 1976 |
| Grant date | Jan 31, 1978 |
| Priority date | — |
| Expiry date | Sep 7, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H77/10
- 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. The auxiliary contacts are carried on a pair of minimum inertia movable contact blades to facilitate rapid separation of the auxiliary contacts. The minimum inertia contact blades are elongated between a pivot point and the point at which the contacts are mounted, where they termin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.