US 4,398,187 AGranted

Pressure monitoring system for a vacuum circuit interrupter

AssigneeMeidensha Corporation

InventorsTomio Fukushima, Shuzo Tanigaki

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Abstract

A pressure monitoring system for a high-voltage vacuum circuit interrupter including a plurality of capacitors connected in series located outside an evacuated housing and between two metallic end plates each attached to the electrode holder and an arc shielding member. The pressure monitoring system which monitors the deterioration of vacuum pressure within the evacuated housing of the interrupter by detecting the change in the electric field intensity of the capacitors dependent upon the change in vacuum pressure comprises a light source, at least one electric field detecting member having a Pockel's cell located on one of the capacitors, light receiving member and a vacuum pressure determining member, whereby an automatic monitoring of vacuum pressure within the evacuated housing of the vacuum circuit interrupter or within each of the evacuated envelopes of a plurality of vacuum circuit interrupters can be made.

Claims19

Dependent claims

A pressure monitoring system in a vacuum circuit interrupter including:

(a) a stationary electrode holder extending through a first metallic end plate into an evacuated housing and having a stationary electrode contact at an end thereof;
(b) a movable electrode holder extending through a second metallic end plate into the evacuated housing and having a movable electrode contact at an end thereof so as to be in contact with or separated from the stationary electrode contact;
(c) an arc shielding member surrounding the stationary and movable electrode contacts within the evacuated housing spaced between the first and second metallic end plates;
and
(d) a plurality of capacitors located outside the evacuated housing and connected between the first metallic end plate and the arc shielding member and between the arc shielding member and the second metallic end plate for dividing the voltage, applied to both stationary and movable electrode contacts, equally among each of said capacitors, the improvement comprising:
(e) a light source;
(f) an electric field detecting member located on one of the capacitors for detecting a change in the electric field intensity within the evacuated housing dependent upon change in pressure within the evacuated housing and controlling the light from said light source according to the detected change in the electric field intensity;
and
(g) a light receiving member for receiving the light from said electric field detecting member and converting it into an electrical signal according to the quantity of light received from said electric field detecting member.

6 more elements

Dependencies are inferred from the claim text.