Document 2.4.126, Revision 4
October 2017
27
Three-Phase Padmounted Distribution Transformers
Inspection Checklist (cont.)
connections and tighten as necessary
(Refer to torque guidelines contained in
Tables 1 through 4).
13.
Replace any damaged or unreadable
nameplates, instructional labels, and safety
labels.
14.
If it is suspected that water or other
contaminates may have entered the tank,
the fluid should be tested to determine
its condition. For transformers filled with
conventional transformer oil, Refer to IEEE
Standard C57.106, Guide for Acceptance
and Maintenance of Insulating Oil in
Equipment. For transformer filled with
less-flammable high molecular weight
hydrocarbon insulating fluid (such as
R-Temp), refer to IEEE Standard C57.212,
Guide for Acceptance and Maintenance
of Less Flammable Hydrocarbon Fluids in
Transformers. For transformers filled with
silicone fluid or seed-based fluid (such
as Envirotemp FR3), contact the Howard
Industries Transformer Division for testing
recommendations.
Electrical Tests
The following tests can be used to determine
the condition of the transformer. Comply with
instructions and precautions provided by the test
equipment manufacturer. Contact the Howard
Industries Transformer Division to discuss any of
these tests.
DANGER
FAILURE TO FOLLOW THE INSTRUCTIONS
BELOW WILL RESULT IN DEATH OR SERIOUS
PERSONAL INJURY, AND EQUIPMENT DAMAGE.
• Energize the transformer from a remote
location.
• Do not energize the transformer using
single-phase switches or fuses. Use only
gang-operated three-phase switches to
energize a three-phase transformer.
• Do not operate the transformer with any of
the primary phases open.
• Only qualified personnel with appropriate
equipment should measure transformer
voltages.
• Be aware of dangerous voltages within the
terminal compartment and avoid personal
contact with live terminals.
• Wear personal protective equipment to
prevent injury from potential arc flash or
contact with dangerous voltages.
• Make sure the transformer is properly
grounded at all times.
• Insulated dead-end caps or plugs must be
installed on all unused dead-front high-
voltage bushings. Dust caps must not be
used in place of insulated dead-end caps or
plugs.
• CT leads must be connected to the
metering load or shorted together and
grounded to prevent dangerous voltages at
the CT terminals.
