Document 2.4.126, Revision 4
October 2017
26
Three-Phase Padmounted Distribution Transformers
Inspection Checklist
Observing the safety instructions above, open the
compartment doors and perform the following
checks.
1.
Inspect for dents or other damage to metal
surfaces and make the necessary repairs
2.
Inspect the cabinet for evidence of
tampering and immediately repair any
damage to ensure cabinet integrity and
prevent unauthorized entry.
3.
Inspect the paint finish for damage,
corrosion or weathering that exposes the
primer coat or bare metal. Repair any paint
damage that might be found. Refer to
“Exterior Paint Finish” for instructions.
4.
Inspect thoroughly for evidence of fluid
leaks, including tank, radiators, bushings,
gauges, switches, valves, fuse holders
and all other accessories. Check the fluid
level gauge or sight glass to determine the
fluid level. Check the pressure-vacuum
gauge (if present) for a zero reading, which
indicates the possibility of a tank leak (The
pressure-vacuum gauge can indicate zero
occasionally, but normally indicates a slight
positive or negative pressure, dependent on
fluid and ambient temperatures). Perform a
pressure test according to the instructions
in “Pre-energization Inspection and Tests.”
Add fluid as necessary to ensure that the
proper fluid level is maintained. Repair as
necessary. Fluid leaks must be repaired
immediately to prevent serious damage to
the transformer and danger to life. Refer to
“Fluid Leaks” for instructions.
5.
Visually check all gaskets for cracking
or other signs of deterioration. Replace
as necessary. When replacing a gasket
carefully clean mating surfaces to remove
any rust, dirt, transformer fluid, old gasket
material, or other contamination that might
prevent a good seal. Use appropriate
gasket cement when installing new gaskets.
Do not reuse old gaskets. Six months after
replacing a gasket, check and re-tighten, if
necessary.
6.
Maintain a clean and unobstructed area
around the transformer, including sufficient
clearance around radiator panels, to ensure
adequate cooling of the transformer.
7.
Inspect the base of the transformer tank
and terminal compartment and make sure
that there is no accumulated dirt or other
debris that might promote corrosion.
8.
Inspect the base of the terminal
compartment and make sure that it is
sitting level and flat on the surface of the
pad with no gaps that might compromise
tamper-resistance.
9.
Check bushings, gauges, switches, fuse
holders and all other accessories for
proper operation and repair or replace any
defective devices.
10.
Check all fasteners for signs of corrosion
and replace as necessary.
11.
Check the fluid temperature gauge,
including the maximum temperature drag
hand (if supplied) to determine whether
the fluid temperature has exceeded the
design limit. Any such indication should be
investigated to determine and correct the
cause.
12.
Check the torque values on all electrical
connections, including the ground
WARNING
FAILURE TO FOLLOW THE INSTRUCTIONS
BELOW MAY RESULT IN DEATH OR SEVERE
PERSONAL INJURY, AND /OR DAMAGE TO
THE EQUIPMENT.
• De-energize transformer from a remote
location before opening cabinet to
perform inspection or maintenance.
• Make sure all transformer terminals and
bushings have zero voltage.
• Make sure that the transformer is
properly grounded.
• Fluid leaks should be repaired as soon as
they are discovered.
