Pressure-monitor for gas encased HV equipment - has thermostat suppressing manometers fault-signal for small temp-induced drops

摘要

The pressure monitor, for encased gas-filled h.v. equipment, has a contact manometer without temperature compensation and a contact thermostat both connected so that a fault-signal from the manometer is suppressed by the thermostat if the pressure inside the casing falls by only a small amount, typically as a result of a drop in temperature. If the pressure falls by a large amount the fault-signal is generated over a second pair of contacts belonging to the manometer independently of the condition of the thermostat. A pressure monitor may be used instead of the manometer's second contacts.