Document 2.4.128, Revision 3
October, 2017
22
Network Transformer Instruction Manual
8. Check all fasteners for signs of corrosion and
replace as necessary.
9. Check fluid temperature gauges, including the
maximum temperature drag hand (if present)
to determine whether the fluid temperature has
exceeded the design limit. Any such indication
should be investigated to determine and correct
the cause.
10. Check torque values on all ground connections
and tighten as necessary. Refer to torque
guidelines contained in Table 6.
11. Replace any damaged or unreadable
nameplates, instructional labels and safety
labels.
12. If it is suspected that water or other
contaminants may have entered the main
tank, switch chamber or terminal chamber,
the fluid or compound 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.
13. Lubricate external parts of the primary
disconnect and grounding switch at least
annually.
14. Exercise the primary disconnect and grounding
switch at least annually.
Electrical Testing
The following electrical tests should be used to
determine the condition of the transformer. Follow
the instructions and precautions provided by the
test equipment manufacturer. Contact the Howard
Industries Transformer Division to discuss any of
these tests.
FAILURE TO FOLLOW THE INSTRUCTIONS
BELOW COULD RESULT IN DEATH OR
SERIOUS PERSONAL INJURY AND MAY ALSO
RESULT IN DAMAGE TO THE EQUIPMENT.
• 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.
• Wear personal protective equipment (PPE)
to prevent injury from potential arc flash or
contact with dangerous voltages.
• Make sure the transformer is securely and
effectively grounded at all times.
• CT leads must be connected to the
metering load or shorted together and
grounded to prevent dangerous voltages
at the CT terminals.
WARNING
DANGER
FAILURE TO FOLLOW THE INSTRUCTIONS BELOW
WILL RESULT IN DEATH OR SERIOUS PERSONAL
INJURY AND MAY ALSO RESULT IN DAMAGE TO
THE EQUIPMENT.
Be aware of dangerous voltages and avoid
personal contact with live terminals
