Electric power distribution system including a Master Annunicator and Central Control Unit
US3983554A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1975 |
| Grant date | Sep 28, 1976 |
| Priority date | — |
| Expiry date | Mar 25, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/18
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An Electric Distribution system for hospital use includes a plurality of ungrounded remote Power Supplies. Each remote Power Supply is provided with a Line Isolation Monitor. A Master Annunciator and Central Control Unit is connected to the several Line Isolation Monitors. The Master Unit, located at a central point, emits an alarm signal whenever the ground leakage current of any Power Supply exceeds a preselected value. The Master Unit also identifies the faulty Supply. Means are provided to measure the magnitude of the ground leakage. In a check mode, the Master Unit will sequentially read the leakage current of each remote Power Supply. In a test mode, the Master Unit will sequentially place artificial ground faults in each remote Supply so as to check the operation of each remote Monitor. Further circuitry may be provided to give an alarm at the Master Unit in the event that any one of the Monitors becomes inoperative due to power failure or loss of ground connection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.