6. Measure the voltage between the top of the
V1
switch and the terminal strip ground marked
G
. The
expected voltage should equal the measured voltage.
A significant difference between the expected and
measured voltages indicates a problem with the PT or
PT connection.
Regulator dry-out procedure
Purpose
The purpose of this procedure is to remove moisture
from the paper insulation, coil, and other components of a
voltage regulator.
Required equipment and information
●
●
Impedance voltage value obtained from factory
●
●
120 V variable power supply
●
●
Cable lead jumper rated for nominal current
●
●
Clamp-on ammeter
●
●
Variable power supply sufficient to apply impedance voltage
●
●
New insulating fluid
●
●
Insulation power factor test equipment
Procedure
WARNING
Hazardous Voltage . This procedure must only be
performed on a regulator that has been removed from
service . Failure to comply can cause serious injury or
death .
1. Remove the unit from service as described in
WARNING
Hazardous Voltage . The regulator will be energized with
load current present for the duration of the procedure .
The regulator must be placed in a protected area,
preventing anyone from coming in contact with the
unit . Failure to do so could result in injury or possible
death .
2. Perform this procedure with the regulator located in
a protected area in the maintenance shop or other
suitable location.
3. Place regulator on the 16 Raise position using external
power. For instruction on connecting the control to an
external source, see Service Information MN225003EN,
CL-7 Voltage Regulator Control Installation, Operation,
and Maintenance Instructions
.
4. Place a jumper, rated for nominal current, between the
S (Source) and L (Load) bushings. A clamp-on ammeter
should be used to measure the current in the shorted
current path.
WARNING
Hazardous Voltage . The regulator tank must be solidly
earth grounded . Failure to comply can cause severe
personal injury and equipment damage .
5. Ground the regulator tank.
6. Using a variac apply impedance voltage at 16 Raise
between the S and L bushings. Raise the voltage until
rated current is read on the ammeter. Impedance
voltage values may be obtained from the factory.
Contact your Eaton representative for assistance.
7. Let the regulator set in this condition for approximately
24 hours. This will drive the moisture out of the coil into
the insulating fluid.
8. De-energize the regulator and drain the insulating fluid.
9. Refill with new insulating fluid.
10. Check the results of the procedure by performing
an insulation power factor test after the regulator
temperature has stabilized to the ambient temperature.
Voltage regulator current test
Purpose
The purpose of this test is to confirm operation of the
current transformer (CT) and voltage regulator control
current measurement.
otee:
N
When performing this test on units with a multi-
phase control, there will not be jumpers available,
as described in step 7, to facilitate connection of
an ammeter. To connect the ammeter, the green
control cable wires connected to the top of the
CCA, CCB, and CCC switches (for VR1, VR2, and
VR3 respectively) can be disconnected and then the
ammeter can be connected between the green wires
and the top of the switches.
Required equipment
●
●
2 - 120 V variable power supply
●
●
Cable lead jumper rated for nominal current
●
●
Clamp-on ammeter
●
●
Small needle-nose pliers
●
●
Milli-ammeter
Procedure
WARNING
Hazardous Voltage . This procedure must only be
performed on a regulator that has been removed from
service . Failure to comply can cause serious injury or
death .
1. Remove the unit from service as described in
32
VR-32 and EVER-Tap™ Voltage Regulator
InstallatIon, operatIon, and MaIntenance InstructIons
MN225008EN June 2020
