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SINGLE POLE HV VACUUM
CONTACTORS / RELAYS
HA
Series
This series of vacuum contactors includes
heavy and very heavy duty types normally used at 400 to 2,000 amps
continuous and 4,000 to 28,000 amps AC interrupt. Some are also used in
conjunction with higher current shunt switches to give continuous duty as
high as 36,000 amps RMS where only moderate current is present during
interruption. Some types are also used for higher current DC interruption
aided by a counter-pulse system which creates artificial current zeros
across the contacts during contact parting. Up to 40,000 amps DC at 40,000
volts has been interrupted by this method. |
HA-73- |
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Units in this series have mechanical lives from 10,000
operations to over 3 million operations depending on contact spacing and
opening speed. Most of the HA series uses contacts made of copper alloy
with a refractory metal base to minimize erosion rate. This combination of
materials provides minimum welding, minimum current chopping and rapid
recovery rate of high dielectric strength after interruption.
Several units have a type of copper alloy without
refractory metal which provides lower contact resistance and high
interruption ratings but allows a higher erosion rate. Very high speed
crobarring and current interrupting models are also available with contact
parting time of 1 to 6 milliseconds and contact closing times as short as
2 to 8 milliseconds when used in conjunction with Ross Engineering SCR
controlled stored energy drivers.
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