| 摘要 |
<p>Each phase (R, S, T) and the neutral(Mp) are connected to a common rail (28) through spark gaps (16, 18, 20, 56) and fuses (22, 24-26, 58). Should an over -voltage occur it is limited by the spark gaps and, dependant upon current, the associated fuse may operate. A system of indicating lamps (36, 38, 40, 52) shows the circuit state. All lamps ON indicates all circuits made and healthy. Loss of a lamp, when not due to lamp failure, indicates operation of a spark gap with power or loss of a main fuse (10, 12, 14). The neutral is also protected against over voltages.</p> |
