Inspection Recommendations
On occasions when the transformer is
taken out of service for maintenance, the
Trans-Rupter II should be tripped, closed,
tripped a second time, and finally closed. To trip
the Trans-Rupter II, inject secondary current
into one of the relays. Also trip the Trans-Rupter
II using the manual-trip device. Follow the steps
in S&C Instruction Sheet 731-503, operating
instructions for tripping the Trans-Rupter II
when the transformer is de-energized.
If the optional test switch is furnished, make
sure its cover is securely in place before re-
energizing the transformer. Also make sure the
pins are removed from the CT shorting blocks.
See Figures 88 and 89.
Refer to the relay manufacturer’s instruc-
tions for recommendations on testing and
inspection of the relays.
Guidelines for
Interrupter Resistance Values
Trans-Rupter II interrupters should have resis-
tance values
under
200 micro-ohms for a new
unit, and
under
500 micro-ohms for a unit that
has been in service. If a Trans-Rupter II unit is
outside these values, contact your nearest S&C
Sales Office.
Inspection Recommendations
To ensure continued proper performance of the
bypass accessory, it should be inspected and
exercised on a five year schedule, or whenever
general substation maintenance occurs. S&C
recommends opening and closing each bypass
blade, checking for corrosion or wear on the
blades.
Figure 88. If furnished, make sure the test-switch cover is in place and
secure.
Test-switch cover
Figure 89. Make sure the pins are removed from the CT shorting blocks.
CT shorting
blocks
Pr
inted in U
.S
.A.
44
S&C Instruction Sheet 731-502
