Howard HI-104 Single-Phase Pad Transformer - Manual (Page 19)

Document 2.4.96, Revision 0
March, 2013
19
Single-Phase Pad-Mounted Compartmental-Type Distribution Transformers
1. Vent the transformer by operating the PRV. Keep
the valve open until the sound of air venting can
no longer be heard. Be careful to avoid contact
with any hot oil that might be expelled from the
PRV.
2. Stand to one side of the Bay-O-Net device being
operated.
3. Attach a live-line tool to the holder eye.
4. Twist the live-line tool to unlock the fuse holder.
5. Rotate the holder 90 degrees clockwise in the
housing to break the seal between the gasket
and the housing.
6. Firmly and quickly pull the fuse holder out about
8 to 10 inches to open the circuit. Wait a few
seconds while the fluid drains back into the tank,
and then completely withdraw the fuse holder.
Wipe the fuse holder and cartridge to remove
excess fluid.
7. If fluid continues to flow from the Bay-O-Net
device, operate the pressure relief valve again to
vent pressure from the tank.
Replace Fuse Link—Replace the fuse according to
the manufacturer’s instructions included with the
replacement fuse.
Re-Insert Fuse Holder—Re-insert the fuse holder us-
ing the following procedure.
1. Using a live-line tool attached to the eye of the
fuse holder, re-insert the holder firmly into the
Bay-O-Net housing.
2. Twist the locking handle, latching it to the shoul-
der of the Bay-O-Net housing. Make sure that
the metal washer is positioned tightly on the end
of the Bay-O-Net housing.
3. Inspect the fuse holder carefully to make sure it
is fully seated and latched properly.
Dead-Break Dry-Well Canister Fuse
The optional dead-break dry-well canister is a fluid-
tight current-limiting fuse holder. It is designed to be
operated with a live-line tool (hot stick or shotgun
stick) and should not be operated by hand. The dry-
well canister is mounted on the transformer front
panel near the high-voltage bushings.
Dead-break dry-well canisters are not designed to
break load and must only be operated when the
transformer is de-energized. When specified, dry-well
canisters are mechanically interlocked with a load-
break switch to prevent removal of the fuses while
the transformer is energized
▲
! WARNING
FAILURE TO FOLLOW THE INSTRUCTIONS
BELOW COULD RESULT IN DEATH OR SERIOUS
PERSONAL INJURY, AND COULD ALSO RESULT
IN DAMAGE TO THE EQUIPMENT.
• Do not operate a dead-break canister fuse
device while the transformer is energized.
• After replacing a blown current-limiting fuse,
the transformer should be re-energized from
a remote location.
The following procedures are intended as a general
guide for operation of the canister fuse device. Per-
sonnel should also read and follow the instructions
provided by the canister fuse device manufacturer
for proper operating procedures and safety informa-
tion.
Remove Fuse Holder—The following procedures
should be used to remove the fuse holder.
1. Make sure the transformer is de-energized.
2. Attach a live-line tool to the hook eye.
3. Quickly pull the fuse holder assembly completely
from the housing.
Replace Fuse—The fuse should be replaced using
the following procedure.
1. Unscrew the fuse from the fuse holder.
2. Replace with new fuse of the appropriate rating
and characteristics.
3. Tightly screw the new fuse onto the fuse holder.
Re-Insert Fuse Holder—Re-insert the fuse holder us-
ing the following procedure.
1. Attach a live-line tool to the hook eye.
2. Insert the fuse holder into the housing.
3. Push the fuse holder in firmly until the dust cap
seats against the housing and grounding clip.