Instruction Book
Effective: March 2007
Page 37
IB6513C80G
For more information visit:
www.EatonElectrical.com
Figure 6-2 Vacuum Interrupter Showing Contact Erosion
Indicator With Breaker Open (Shown here for clarity
purposes only)
Figure 6-3 Vacuum Interrupter Showing Contact Erosion
Indicator With Breaker Closed (Indicators are checked
only when breaker is closed)
WARNING
FAILURE TO REPLACE A VACUUM INTERRUPTER
ASSEMBLY WHEN CONTACT EROSION MARK IS
NOT VISIBLE OR WIPE IS UNSATISFACTORY, WILL
CAUSE THE BREAKER TO FAIL TO INTERRUPT AND
THEREBY CAUSE PROPERTY DAMAGE OR
PERSONAL INJURY.
6-6 INSULATION
In DHP-VR breakers, insulation maintenance primarily
consists of keeping all insulating surfaces clean. This
can be done by wiping off all insulating surfaces with a
dry lint free cloth or dry paper towel. In case there is any
tightly adhering dirt that will not come off by wiping, it
can be removed with a mild solvent or distilled water.
But be sure that the surfaces are dry before placing the
breaker in service. If a solvent is required to cut dirt, use
Stoddard
’
s Solvent Cutler-Hammer 558 12CA or
commercial equivalent. Secondary control wiring
requires inspection for tightness of all connections and
damage to insulation.
6-7 INSULATION INTEGRITY CHECK
PRIMARY CIRCUIT:
The integrity of primary insulation may be checked by
the AC high potential test. The test voltage depends
upon the maximum rated voltage of the breaker. For the
breakers rated 4.76 kV, 8.25 kV and 15 kV, the test volt-
ages are 15 kV, 27 kV and 27 kV RMS, 60 Hz
respectively. Conduct the test as follows:
Close the breaker. Connect the high potential lead of
the test machine to one of the poles of the breaker.
Connect the remaining poles and breaker frame to
ground. Start the machine with output potential at zero
and increase to the test voltage. Maintain the test volt-
age for one minute. Repeat for the remaining poles.
Successful withstand indicates satisfactory insulation
strength of the primary circuit.
If a DC high potential machine is used, make certain
that the peak voltage does not exceed the peak of the
corresponding AC RMS test voltage.
SECONDARY CIRCUIT:
Isolate the motor by pulling apart the two insulated quick
disconnecting terminals in the two motor leads provided
for this purpose. Connect all points of the secondary
disconnect pins with a shooting wire. Connect this wire
to the high potential lead of the test machine. Ground
the