always include the following items of information from the
transformer’s nameplate: Serial number, style number, KVA
rating, high voltage and low voltage ratings.
Additionally, all applicable safety procedures such as OSHA
requirements, regional and local safety requirements, safe
working practices and good judgement must be used by
such personnel.
3.0 RECEIVING
WARNING:
DO NOT LIFT THE TRANSFORMER
BY USING CRANES OR JACKS ON ANY PART OF
THE TRANSFORMER OTHER THAN THE LIFTING
HOOKS OR JACKING PADS PROVIDED FOR THIS
PURPOSE. IMPROPER LIFTING OR JACKING CAN
CAUSE SEVERE INJURY AND/OR PROPERTY
DAMAGE.
The Unit Substation Transformer is normally shipped as a
complete sub-assembly and ready to install in the field with
mating high voltage switchgear section and low voltage
section. Each transformer should be carefully inspected
upon receipt and the transportation company notified of any
damage that has been incurred. The shipping list should be
checked for possible shortages.
Unit Substation Transformers are normally shipped on a
pallet. Palletized transformers may be moved readily by a
lift truck, crane, or cart. The lifting hooks supplied on the
sides of the transformer enable it to be lifted by crane.
Be sure the device chosen has the capacity to lift, or move,
the complete unit. (Weight is shown on the nameplate.)
Lift the transformer utilizing all the hooks and use proper
spreaders to obtain a vertical lift.
Air Terminal Chambers (ATC’s) with hinged access panels
are furnished with either “hex-head” or when specified
“penta-head” locking bolt that must be loosened to open
the compartment. This bolt can be turned with a standard
socket (wrench), as used widely in the utility industry.
4.0 EXTERNAL INSPECTION
WARNING:
THE OIL MUST BE AT THE PROPER
LEVEL (25° C LEVEL) BEFORE VOLTAGE IS
APPLIED TO THE TRANSFORMER. FAILURE
TO MAINTAIN THE PROPER OIL LEVEL CAN
CAUSE SEVERE PERSONAL INJURY, DEATH OR
SUBSTANTIAL PROPERTY DAMAGE.
The oil level should be checked by inspecting the liquid level
gauge. Any unit which does not have the proper oil level
should be checked for leaks and refilled before placing in
service. Refilling with oil is an unusual field condition and
requires extreme care. The first priority is to determine the
reason for the low oil level and may require leak repair or
replacement of defective gaskets or seals.
If the oil level is slightly below normal but still above the
internal transformer windings, oil can be added in the
field by using the fill couplings. Refer to the nameplate
to indicate the type of oil that is used and only fill with oil
that is approved. Take caution to ensure that the correct
fluid is used and ensure that other contaminates are not
introduced. Use only quality oil per ASTM D3487 when
adding oil to the transformer. The transformer was filled
or processed at the factory with non-PCB dielectric fluid
in accordance with Federal Polychlorinated Bi-phenyl
(PCB) Regulations 40 CFR 761, et seq. The non-PCB fluid
contained less than 1ppm PCB at time of processing or
filling. The owner should take the necessary precautions so
that PCB contamination is not introduced during field filling
or maintenance of the transformer (refer to Fig. 2).
If the oil level is below normal and the transformer
windings are exposed to air, then field addition of
oil is not possible as trapped air in the windings can
lead to dielectric failure. In this case, the substation
transformer must be returned to a service facility for
vacuum oil filling
.
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