Cleaning; Field Service - HPS EnduraCoil 1.2 KV Manual De Instrucciones

Cleaning

DANGER
Failure to de-energize and ground the transformer
before opening the enclosure and/or working
on the transformer will result in serious personal
injury or death.

Field Service

DANGER
Failure to de-energize and ground the transformer
before opening the enclosure and/or working
on the transformer will result in serious personal
injury or death.
Electrical equipment should be installed, operated,
serviced, and maintained, only by qualified
personnel.
Installation, Operation, and Maintenance Guide - Cast Resin Transformers
If excessive accumulation of dirt is apparent on the transformer
windings or insulators, the dirt must be removed to permit
the circulation of air. Particular attention should be given to
cleaning the top and bottom ends of the winding assemblies
and to cleaning ventilation ducts.
The windings may be cleaned with a vacuum cleaner, blower,
or with compressed air. A vacuum cleaner is preferred as a first
step followed by the use of compressed air. The compressed air
should be clean and dry and applied at a relatively low pressure
(not over 25 pounds per square inch). Leads, lead supports, coil
support, terminal boards, bushings and other major insulating
surfaces should be brushed or wiped with a dry cloth. The use
of liquid cleaners is undesirable due to solvents which could
have a detrimental effect on insulating materials.
The following is intended as a troubleshooting guide to help
determine corrective measures for power transformers in the
field. It is emphasized that only qualified personnel should
be permitted to examine installed transformers. Transformer
must be de-energized before any work is conducted on a
transformer. It is also recommended that all terminals be
grounded.
1. Overcurrent
Fully loaded transformers may appear warm to the touch.
Standards permit the temperature of the transformer enclosure
cover to be 65°C rise (149°F) [80°C (176°F) in a not readily
accessible location] over ambient which at 40°C(104°F)
ambient could be a maximum of 105°C (221°F) and [120°C
(248°F) in a not readily accessible location] continuous. In this
condition, the temperature on a thermometer could be at the
maximum of 220°C (428°F).
When temperatures exceed this, overheating of the
transformer occurs and that may damage the transformer.
Check for these conditions:
 continuous overloads for long time periods
 wrong external connections
 excessive input voltage or current
 voltage or current harmonics
 poor room ventilation or heating from other sources
 high ambient temperatures [standards permit 30°C
(86°F) average, 40°C (104°F) maximum]
 blocked air ducts or ventilation openings, filters
 accumulation of dirt and dust restricting air circulation.
continued on following page
14