With the contact closed, auto operation will be inhibited.
The CL-7 control will illuminate the Auto Tap Blocked LED
and display
Blockede: CL
or
Comm
on the Metering-PLUS
Load Current screen.
Untanking the regulator
CAUTION
Equipment Misoperation . Do not subject tap-changer
with phenolic contact boards to temperatures above
150 °F (66 °C) . To do so may cause damage to the
contact panels, resulting in misalignment of the
contacts, and can cause personal injury and equipment
damage .
CAUTION
Equipment Damage . Before untanking a regulator that
contains a thermometere: (1) Lower the insulating fluid
level below the thermometer, then; (2) Remove the
thermometer well . Failure to do so will result in damage
to the thermometer well and can cause spillage of the
insulating fluid when the internal assembly is lifted,
causing personal injury .
CAUTION
Equipment Damage . Do not suspend the control
box using the control cable . The control cable is not
designed to support the weight of the control box .
The control box can fall, causing personal injury and
equipment damage .
Before untanking a voltage regulator, remove it from
service following the instructions found in this manual
in
on page 11. Untanking is
performed in order to inspect the internal components and
perform maintenance. A voltage regulator can be partially
untanked for most routine maintenance and inspections. If
a more in-depth inspection or maintenance is needed, a full
untanking can also be performed.
Steps for untanking:
1. Manually run the tap-changer to neutral. If that tap
changer cannot be returned to neutral, record the
position indicator reading before proceeding so the
position indicator can be returned to the correct
position before retanking.
2. Disconnect the control cable from the bottom of the
junction box (see
).
3. Remove the series arrester to avoid damaging
the arrester and bushings while lifting the internal
components.
4. Release the tank pressure by pulling the ring on the
pressure-relief device located on the side of the tank.
5. Free the cover by removing the cover band or cover
bolts.
WARNING
The lifting eyes on the top of the voltage regulator are
to be used for untanking only . Attempting to lift the
entire voltage regulator using the lifting eyes could
cause the tank to separate from the cover and fall to
the ground . This could cause death, personal injury, or
property damage .
6. Attach lifting straps with a spreader bar to the lifting
eyes on top of the cover.
WARNING
Personal Injury . Do not rely on the lifting apparatus
when the internal assembly is lifted for inspection or
maintenance . Blocking should be placed between the
cover and the top of the tank when partially untanking
the voltage regulator to keep the assembly from falling,
which can cause death or severe personal injury and
equipment damage .
7. Lift the assembly:
a.
For partial untankinge:
lift the assembly until the
top of the coil is approximately one inch under the
insulating fluid (see
b.
For Full untankinge:
lift the assembly until the
bottom of the assembly clears the tank. The
assembly can be suspended for a period of time
until the oil dripping slows. The internal assembly
can then be placed on a drip tray. Make sure to
return the core and coil to oil within 4 hours.
27
VR-32 and EVER-Tap™ Voltage Regulator
InstallatIon, operatIon, and MaIntenance InstructIons
MN225008EN June 2020
