| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage detecting and grounding unit for preventing a short-circuit accident resulting from contact of small animals with resistors for voltage measurement, as well as protecting against breakage of the unit in case a short-circuit accident. SOLUTION: On a bottom plate 1a of a box-shaped body 1, an exhaust door 2 which is pushed open downward for burst prevention is installed. The exhaust door 2 is always locked by means of a stopper 3a of a solenoid 3, and is opened through releasing of the stopper 3a when a thermo sensor detects temperature rise inside the box-shaped body 1. A grounding device 6 that is a vacuum electromagnetic contactor is fixed in the box-shaped body 1. The grounding device 6 serves as a switching means between contact lines and rails. The grounding device 6 is usually open but can be closed when no-voltage condition on the contact lines is detected. Resistors 11a, 11b for detection of voltage on the contact lines are connected with a conductive bar 10b leading to the grounding device 6. The resistors 11a, 11b are housed in a tubular insulating case 12. On the periphery of the insulating case 12, an umbrella-shaped rib member 12a is installed.
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