Vacuum Relays Switching Characteristics
Vacuum relays are available in SPST normally open (N/O) and normally
closed (N/C) models, as well as SPDT, DPDT, and 4PDT configurations.
Latching relays are available in some models. These relays are available
in two main configurations: ground isolated designed for hot switching,
and non-isolated meant for cold switching. Ground isolated relays have
their operating elements insulated from the ground plane to provide
absolute voltage isolation between the housing and the high voltage
contacts...up to 15,000 V peak.
Non-isolated relays have the operating coil assembly outside the vacuum
for easy coil replacement, should that ever be necessary. Certain types
come with refractory metal contacts which will not stick or weld if
hot switched. Others have copper alloy contacts for use in circuits
where current will not be interrupted by the relay contacts. This alloy
offers minimum contact resistance and high current handling capability.
Mounting Jennings vacuum relays is accomplished either by a threaded
coil housing, a flange, or a clamp mounting. Heavier models have mounting
brackets. All models may be mounted and operated in any position.