Installation
Pre-installation inspection
Before connecting the regulator to the line, make the
following inspection:
1. Check insulating fluid level sight gauge. Look for visible
signs of leaking insulating fluid.
otee:
N
The site gauge is at the 25 °C insulating
fluid level. Fluid may not be visible in cold
temperatures.
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
evidence of moisture such as rust or water tracks in the
insulating fluid. If moisture has entered the tank, dry
regulator and filter the insulating fluid before putting
unit in service. See
for insulating fluid test standards. 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 insulating fluid according to
7. Regulator may be energized at rated voltage (with
caution); you can then perform the
on page 25. 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
WARNING
Hazardous Voltage . Connect the “S” bushing to
the source, the “L” bushing to the load . For Wye
connections, connect the “SL” bushing to neutral .
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 .
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 connected 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 connection diagrams
are illustrated in
through
. Refer to
on page 13 for information on shunt
arrester application.
otee:
N
In the typical connection diagrams (
), individual switches are shown
for the bypass and disconnect functions. However,
a regulator-bypass-disconnect 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.
Ø
N
Source
Load
Control
Box
Figure 3 . Regulating a single-phase circuit
A
B
C
N
Source
Load
Control
Box
Figure 4 . Regulating one phase of a three-phase, four-
wire circuit regulator
4
VR-32 and EVER-Tap™ Voltage Regulator
InstallatIon, operatIon, and MaIntenance InstructIons
MN225008EN June 2020
