Abstract: The invention is directed to an arrangement for detecting deficient operational capability in a vacuum switching vessel. The arrangement can provide a signal if a fault occurs which affects the operability of the switching vessel. Instead of a signal, a protective device alone or together with the signal can also be caused to respond. The arrangement includes a body of a material which changes its physical characteristics substantially in a limited temperature interval and is attached in heat-conducting contact with a part of the vacuum switching vessel which has a temperature time constant as small as possible. This change of the characteristics of the body acts to initiate the above-mentioned signal or action of the protective device. The invention is suited particularly for application in switchgear with vacuum switching vessels.

Abstract: The invention is directed to an arrangement which serves to detect deficient operational capability of vacuum switching vessels and which causes a signal to be given if a fault affecting the operability occurs. Instead of the signal, a protective device alone or together with the signal can also be caused to respond. According to the arrangement of the invention, the electromagnetic radiation emanating from the vacuum switching vessel is gathered by means of a detector and evaluated for providing the signal or initiating the action of the protective device. The range of the electromagnetic radiation in the region of thermal radiation is especially suitable for use. The invention is suited particularly for application in switchgear equipped with vacuum switching vessels.