Field-installable heavy duty undervoltage release
US4947284A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Mar 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2083/203
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An undervoltage tripping unit for a power line circuit breaker features a holding solenoid and a boostig solenoid having their associated plungers coupled to move together so as to be retracted against the force of plunger biasing springs when both solenoids are energized. Release of the plungers from the retracted position is used to trip the associated power line circuit breaker when the line voltage falls below a tripping voltage level. The holding solenoid is continuously coupled to the circuit breaker power input terminals. The booster solenoid is energized through a plunger-actuated switch so as to be de-energized when the plungers are fully retracted or in a position proximate thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.