Howard Medium Power Substation - Manual (Page 12)

Document 2.4.06, Revision 4
June 2013 Medium Power Substation Transformers
Filling Installed Radiators with Fluid
Follow the steps below to fill installed radiators with
insulating fluid.
DANgER : TRANSFORMER OIl SHOUlD
AlWAYS BE HANDlED AS A FlAMMABlE FlUID.
SEAlED TRANSFORMER TANKS MAY UNDER SOME
CONDITIONS ACCUMUlATE EXPlOSIvE GASES, AND
HANDING OF TRANSFORMERS MAY GENERATE
STATIC ElECTRICITY. SAFETY PRECAUTIONS BEFORE
OIl-FIllING OR FIlTERING SHOUlD INClUDE
PURGING All GAS SPACES WITH NITROGEN AND
GROUNDING THE TRANSFORMER, All BUSHINGS,
AND All OIl HANDlING EQUIPMENT. FAIlURE TO DO
SO COUlD RESUlT IN SEvERE PERSONAl INJURY,
DEATH, OR EQUIPMENT DAMAGE.
WARNINg : TRANSFORMERS SHOUlD NOT BE
lEFT UNDER vACUUM EXCEPT DURING THE
vACUUM FIllING OPERATION. THE TANK SHOUlD
BE UNDER POSITIvE PRESSURE DURING PERIODS
OF RAIN OR HIGH HUMIDITY IN ORDER TO PREvENT
MOISTURE FROM BEING DRAWN INTO THE TANK.
FAIlURE TO FOllOW THESE PRECAUTIONS COUlD
RESUlT IN SEvERE PERSONAl INJURY, DEATH, OR
EQUIPMENT DAMAGE.
Every container or tote of transformer fluid used in the
filling process should be visually inspected and tested
for water and other possible contaminants before
proceeding with the filling process.
During the process do not allow the fluid level to drop
below the top of the core and coil assembly. If the
fluid level in the transformer becomes too low, stop the
radiator filling procedure and add fluid to the tank before
completing the filling process.
1. loosen the top header plugs and slowly open
the bottom radiator valves one at a time to start
the flow of fluid.
2. Add fluid to the tank if necessary during the
process to maintain fluid level in the tank at its
proper level.
3. After the radiators are filled, open the top
radiator valves.
4. Remove the top header plugs and reinstall them
using Teflon pipe thread tape.
5. Ensure that top and bottom radiator valves on
each radiator are in the full “OPEN” position.
6. Observe the fluid level gauge and ensure that
the fluid level is correct. If the level is low, add
fluid to the tank.
Installation of High-voltage Bushings
Transformers are usually furnished with draw-lead or
condenser type high-voltage bushings. If bushings
were removed prior to shipment and shipped separately
from the transformer, install them according to the
instructions below.
WARNINg : DO NOT OvERSTRESS BUSHINGS
WHEN MAKING CONNECTIONS TO AvOID
DAMAGE. DAMAGED BUSHINGS COUlD CAUSE
SEvERE PERSONAl INJURY, DEATH, OR PROPERTY
DAMAGE.
Installation of Draw-lead Bushings
If draw-lead type bushings are furnished, install each
bushing as follows.
1. Remove the blind flange covering the bottom
end of the bushing.
2. locate and uncoil the draw lead.
3. Install the gasket supplied with the bushing to
the bushing boss. For cork-neoprene gaskets,
apply a uniform coating of gasket cement to
the gasket area of the bushing boss and to the
bottom of the gasket. Allow cement to become
tacky and then position gasket on the bushing
boss. Then apply a thin coating of petrolatum
to the top surface of the cork-neoprene gasket.
For nitrile or viton gaskets, apply a thin coating
of petroleum jelly to the bottom surface of the
gasket and place the gasket in the center of the
gasket area on the bushing boss.
WARNINg : WHEN APPlYING GASKET
CEMENT, KEEP All SPARKS AND FlAMES
AWAY FROM WORK AREA. AvOID BREATHING lARGE
QUANTITIES OF vAPOR AND AvOID CONTINUOUS OR
EXCESSIvE CONTACT WITH SKIN. FAIlURE TO DO SO
COUlD RESUlT IN SEvERE PERSONAl INJURY OR
DEATH.
4. Insert a fish wire through the bushing porcelain
and attach the bottom end of it to the top of the
terminal on the end of the draw lead.
5. Straighten the draw lead, so that it is free of
twists and kinks.
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