5.0 INTERNAL TANK INSPECTION
WARNING:
ALWAYS VENT THE TRANSFORMER
BY FOLLOWING THE INSTRUCTIONS IN SECTION
7.3. FAILURE TO DO SO CAN CAUSE SEVERE
PERSONAL INJURY, DEATH OR SUBSTANTIAL
PROPERTY DAMAGE .
CAUTION:
WHEN A TRANSFORMER IS OPENED,
TAKE ACTION TO PREVENT ENTRANCE OF
MOISTURE OR FOREIGN OBJECTS. MOISTURE,
DIRT OR FOREIGN OBJECTS CAN WEAKEN THE
INSULATION OF A TRANSFORMER AND GREATLY
SHORTEN ITS LIFE.
The transformer covered by this instruction is shipped ready
for installation and does not require internal inspection;
however, if the transformer must be opened, prevent the
entrance of moisture or other foreign material
6.0 STORAGE
The transformer should be stored completely assembled
(tank sealed and cabinetry closed) as though it were
energized and at its permanent location. Transformers
should not be stacked on top of one another, and care
must be exercised to prevent submersion in water. The
transformer should be stored on a solid, level foundation.
In the event a transformer is to be held in storage for a
period in excess of one (1) year, it is recommended the
space above the oil be pressurized with dry air to two (2)
to three (3) psig. This will prevent moisture ingress due to
negative pressure.
The transformer will be ready for service at any time
provided it has received the inspections outlined in Sections
4.0 and Section 7.0 thru 7.7.
7.0 INSTALLATION
Installation should comply with the latest edition of the
National Electrical Code and other applicable local building
codes.
7.1 Mounting
WARNING :
FAILURE TO PROPERLY MOUNT THE
TRANSFORMER CAN CAUSE SEVERE INJURY,
DEATH OR PROPERTY DAMAGE.
The transformers should be mounted on a flat level pad
strong enough to support the weight of the transformer.
The unit should not be tilted in any direction greater than
1.5 degrees, as a greater tilt will cause deviations in liquid
level near live parts, pressure relief devices, or other
accessories specifically located at or near the 25 degree
C liquid level.
CAUTION:
DEVIATIONS FROM SPECIFIED OIL
LEVEL CAN INCREASE THE POSSIBILITY OF A
DISRUPTIVE FAILURE.
Unit substation transformers must be adequately anchored
and secured to the pad. When seismic conditions are
specified, heavy duty seismic anchors are necessary to
meet seismic conditions. (Refer to Fig. 3).
7.2 Location
These transformers either contain flammable insulating
mineral oil fluid or less flammable seed oil. Refer to the
nameplate for the specific fluid that is provided.
For transformers that contain mineral oil which is considered
a flammable fluid, transformer failure can cause fire and/
or explosion. This possibility should be considered when
locating these transformers in close proximity to buildings
or public thoroughfares. Refer to the latest edition of the
National Electrical Code and local building codes.
7.3 Venting
Vent the transformer by manually operating the pressure
relief device provided. The transformer should be vented
before it is energized if it has been pressurized for leak test
or if the unit has been opened and resealed.
7.4 Grounding
WARNING:
THE TRANSFORMER MUST BE
PROPERLY GROUNDED PRIOR TO ENERGIZING.
FAILURE TO PROPERLY GROUND CAN CAUSE
SEVERE INJURY OR DEATH.
A good, permanent low impedance ground connection must
be made to the tank by using the ground pad(s) provided
near the bottom of the tank for this purpose.
Transformers which are designed for use on a grounded
wye system, that is, one having a solidly grounded neutral,
must have the tank and other available neutrals permanently
and solidly grounded to the common neutral of the system
before the transformer is energized.
When supplied neutral grounding resistors are designed to
ground the low voltage system. Ensure that final mounting
is complete and proper electrical connections are made
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