Pre-installation Inspection
Before connecting the regulator to the line, make the fol-
lowing inspection:
.
Check oil sight gauge. Look for visible signs of oil leak-
age.
2 .
Examine series arrester for damage. If damaged, install
a new arrester of same voltage rating.
3 .
Inspect porcelain bushings for damage or leaking
seals.
4 .
If there is a suspicion that moisture has entered the
unit, remove the hand-hole cover and inspect for evi-
dence of moisture such as rust or water tracks in oil. If
moisture has entered the tank, dry regulator and filter
oil before putting unit in service. See Tables 5 and 6 for
values that oil should meet. Be sure to properly replace
hand-hole cover.
5 .
Check position indicator for damage. When cleaning
the faceplate, do NOT use solvent or fuel.
6 .
If the regulator has been stored for some time, test the
dielectric strength of the oil according to Tables 5 and
6.
7 .
Regulator may be energized at rated voltage (with cau-
tion) and an operational check can be performed. (This
procedure is optional.)
8 .
A high-potential test may be done to ensure adequate
electrical clearances to ground. (This procedure is
optional.)
Systems Connections
A regulator can regulate a single-phase circuit or one
phase of a three-phase wye (star) or delta circuit. Two
regulators connected phase-to-phase in open delta or
three regulators connected phase-to-phase in closed delta
can regulate a three-phase, three-wire circuit. When con-
nected in wye, three regulators can regulate a three-phase,
four-wire, multi-grounded wye circuit. Three regulators
should not be connected directly in wye on three-phase,
three-wire circuits because of the probability of neutral
shift, unless the neutral is connected to the neutral of a
wye-connected bank of distribution transformers or to the
substation transformer secondary neutral. Typical connec-
tion diagrams are illustrated in Figures 4—8. Refer to the
Shunt Arresters section of this manual for information on
shunt arrester application.
NOTE:
Individual switches are shown for the bypass and dis-
connect functions. However, a regulator-bypass-discon-
nect switch can be used in each phase to perform the
bypassing and disconnecting operations in sequence.
Each of these switches replaces one bypass and two
disconnect switches shown in the diagrams.
VR-32 Voltage Regulator Installation, Operation, and Maintenance Instructions
6
Figure 4 .
Regulating a single-phase circuit .
Shunt
Arresters
Series
Arrester
Disconnects
Bypass Switch
Ø
N
SL
Load
Source
S
L
INSTALLATION
WARNING:
Hazardous Voltage. Connect the "S"
bushing to the source, the "L" bushing to the load.
For Wye connections, connect the "SL" bushing to neu-
tral. For Delta connections, connect the "SL" bushing
to the appropriate phase. Inaccurate connections may
cause excessively high or low voltage on the load side
of the regulator and can cause death or severe personal
injury and equipment damage.
VR-T219.0
