Removal from Service
determining Neutral Position
Return the regulator to neutral. Only a regulator in the neu-
tral position can be safely removed from service without
interrupting load continuity. It is recommended to use more
than one method to determine the neutral position.
Return the Regulator to Neutral
.
Use the
Raise/Lower
switch to bring the regulator to
neutral position.
2 .
When in neutral, the
Neutral Light
will be continuously
lit and the position indicator will point to zero (Neutral).
3 .
Verifying the neutral position of the regulator using four
methods:
A .
Verify that the neutral indicator light on the control
is indicating the neutral position. Neutral is indicat-
ed only when the light is continuously illuminated.
B .
Verify the tap position of the control indicates neu-
tral.
C .
Verify that the position indicator on the regulator is
in the neutral position.
D .
Using an acceptable method, verify that there is
no voltage difference between the source and load
bushings.
4 .
When the regulator has been placed in the neutral
position, but prior to bypassing, additional safety action
must be taken to ensure that the tap-changer will not
inadvertently switch to an off-neutral position. This can
be accomplished by doing the following:
A .
Place the
CONTROL FUNCTION
switch in the
Off
position.
B .
Remove the motor fuse.
C .
Place control
POWER
switch in the
Off
position.
D .
Open
V
knife switch (and
V
6
if present) located on
control back panel (see Figure 11).
De-energizing the Regulator
Once it has been established that the regulator is on neu-
tral, immediately proceed with the following steps:
.
Place
CONTROL FUNCTION
switch in the
Off
posi-
tion.
2 .
Place control
POWER
switch in the
Off
position.
3 .
Open
V
knife switch (and
V
6
if present) located on
control back panel (see Figure 11).
4 .
Remove the 6 A motor fuse.
5 .
Close bypass switch.
6 .
Open load (L) disconnect switch.
7 .
Open source (S) disconnect switch.
8 .
Open source-load (SL) disconnect switch, if available.
NOTE:
If a regulator bypass disconnect is used in place of three
separate switches, steps 5, 6 and 7 are carried out in one
operation.
3
S225-10-30
!
SAFETY
FOR LIFE
WARNING:
Explosion Hazard. To stop the reg-
ulator on the neutral position, the CONTROL
FUNCTION switch should be returned to Off during the
switching operation from positions 1R or 1L to position
Neutral. Switching to Off prior to reaching the neutral
position prevents overshoot. Failure to comply can result
in death or severe personal injury and equipment dam-
age.
VR-T208.0
WARNING:
Explosion Hazard. Always use the
CONTROL FUNCTION switch (labeled Auto/
Remote, Off, Manual and Raise or Lower) to operate the
regulator, not the power switch. Failure to comply can
result in the tap-changer stepping off of neutral immedi-
ately upon being energized, causing personal injury and
equipment damage.
VR-T207.0
DANGER:
Explosion Hazard. During bypass
switching, the regulator must be in the neutral
position. Prior to bypass switching: 1) The regulator
must be placed in the neutral position; 2) Tap-changer
operation must be disabled during the bypass switch-
ing. If the regulator is in any other position, part of the
series winding will be shorted when the bypass switch
is closed, resulting in high circulating current. Failure to
comply will result in death or severe personal injury and
equipment damage.
VR-T205.0
WARNING:
Explosion Hazard. After placing the
regulator in the neutral position for bypass switch-
ing, always disable the motor to prevent a tap change
during bypassing which can result in the tap-changer
stepping off of neutral. Failure to comply can cause
death or severe personal injury and equipment damage.
VR-T209.0
WARNING:
Explosion Hazard. Bypass a regula-
tor with the line energized only if both the position
indicator and the neutral light indicate neutral. If both do
not indicate neutral, the line should be de-energized to
avoid shorting part of the series winding and resultant
high circulating current. Failure to comply can result in
death or personal injury and equipment damage.
VR-T206.0
