Document 2.4.128, Revision 3
October, 2017
14
Network Transformer Instruction Manual
The following operating instructions and descriptions
of switching and protective devices are intended
to be a general guide for operation of Howard
secondary network transformers in normal
environments. Although efforts have been made
to ensure accuracy and completeness, these
instructions and descriptions do not address every
conceivable application or circumstance that might
be encountered. Personnel should read and comply
with any safety and instructional labels that might
accompany an accessory device.
Some of the accessory devices described below are
optional and may not be supplied on any particular
transformer design. The inclusion of particular
accessory device in any transformer design is
governed by industry standards and by individual
user specifications.
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 operate load-break equipment if a
fault condition is suspected.
• Do not operate a no-load tap changer,
series/multiple switch, or delta/wye
switch while a transformer is energized.
• Use a live-line tool (hot stick or shotgun
stick) to operate transformer load-break
equipment.
• After operating transformer loadbreak
equipment, check that voltages at
transformer terminals are the expected
values. Checking voltages verifies that
loadbreak equipment operated properly
and that electrical circuit conditions are as
expected.
• Before servicing the transformer,
ALWAYS de-energize the transformer,
and then proceed to ground all primary
and secondary transformer terminals
following industry accepted safe grounding
practices. Place the network protector in
the “OPEN” position. Then operate the
primary disconnect switch, moving the
handle to the “GROUND” position.
• Follow industry accepted safety practices
and utilize personal protective equipment
(PPE) when working with this equipment.
• Do not operate fluid-immersed load-break
switching devices when the insulating fluid
temperature is below the following limits:
-20°C (-4°F) for conventional
transformer oil and silicone fluid
-0°C (32°F) for R-Temp fluid
-10°C (14°F) for FR3 fluid
WARNING
SECTION 5: OPERATION OF SWITCHING AND PROTECTIVE DEVICES
