Methods and apparatus for calibrating a thermomagnetic trip unit of a circuit breaker
US9396899B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 2012 |
| Grant date | Jul 19, 2016 |
| Priority date | — |
| Expiry date | Mar 5, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H73/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Methods, apparatus, and systems are provided for calibrating a thermomagnetic trip unit in a circuit breaker base assembly. An apparatus for calibrating a trip unit includes a calibration nut, an extended armature guide pin having a threaded portion, a spring disposed on the calibration nut and coiled around the extended armature guide pin, and an armature disposed on the spring and adapted to be held by an electromagnet. The calibration nut is threaded on the threaded portion of the extended armature guide pin and adapted to translate up or down depending on rotation of the extended armature guide pin to compress or decompress the spring against the armature. The extended armature guide pin includes a slotted end that is accessible when the apparatus is installed in the circuit breaker base assembly. The calibration nut is also accessible when the apparatus is installed in the circuit breaker base assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.