发明名称 |
SAFETY DEVICE FOR DETECTING INSULATION FAULTS ON AN ELECTRICAL APPLIANCE |
摘要 |
The present invention relates to a security apparatus connected to the circuit of a machine in order to detect the presence of a fault therein such as a short circuit or loss of insulation between a power line and ground. The security apparatus comprises a tripping circuit having at least one transistor which is normally nonconductive and becomes conductive only when a fault current is fed to its base. The collector current activates a circuit breaking device and/or a signalling device which are continuously energized. The security apparatus operates, depending on its mode of connection, in response to a relatively small detected fault current resulting, for example, from defective insulation or from a short circuit. The security provided is irrespective of the state of the ground of the apparatus being protected. |
申请公布号 |
ZA7600589(B) |
申请公布日期 |
1977.01.26 |
申请号 |
ZA19760000589 |
申请日期 |
1976.02.02 |
申请人 |
PARRIER A;PARRIER H;PARRIER J |
发明人 |
PARRIER A;PARRIER H;PARRIER J |
分类号 |
G01R31/02;H02H3/14;H02H3/16 |
主分类号 |
G01R31/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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