Circuit breakers with PTC (Positive Temperature Coefficient resistivity
US5886860A · kind A · utility
38Cited by
39References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Aug 25, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/33
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A Positive Temperature Coefficient Resistivity (PTC) element has a resistivity that increases as the temperature increases. Circuit breakers having PTC elements can achieve better overload and short circuit protection than existing products. Breakers with PTC elements can also be combined with ground fault detection circuits to activate the circuit breaker under ground fault conditions that are less severe than the overcurrent conditions that would normally activate the circuit breaker. A shunt trip assembly incorporating a PTC resistor reduces the required power rating of the clearing switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.