ufacturer has generally validated mill maintenance
decisions to remove a breaker from service and replace
it, based on infrared scan results. Periodic infrared
scanning used as a tool in identifying potential problems
with sealed molded case circuit breakers will be
discussed. This and other breaker off-line testing
methods used at this site will be reviewed. Finally, overall
reliability improvement and impact on the results of the
existing mill-wide safety compliance programs will be
summarized.
Index Terms – Risk Management, Electrical Safety
Program, Infrared Thermography, Molded Case Circuit
Breakers, Predictive Maintenance, NFPA70E Standard.
I. INTRODUCTION
A number of presentations from past Institute of Electrical and
Electronics Engineers (IEEE) Conferences and Electrical
Safety Workshops have focused on the reliability and
maintainability of molded case circuit breakers as a factor in
developing a credible facility safety program. Most certainly,
proper maintenance of any electrical product is necessary to
assure reliable operation. However, past assertions such as
“Several studies have revealed that circuit breakers that were
not maintained within a period of five years have a 50%
probability of failure” [1] and “If a breaker has not been
operated within as little as 6 months, it should be removed
from service and manually exercised” [2] and “Maintenance of
molded case circuit breakers is limited to proper mechanical
mounting, electrical connections and periodic manual
operation” [3] tend to be misleading. In actual practice, circuit
ufacturer has generally validated mill maintenance
decisions to remove a breaker from service and replace
it, based on infrared scan results. Periodic infrared
scanning used as a tool in identifying potential problems
with sealed molded case circuit breakers will be
discussed. This and other breaker off-line testing
methods used at this site will be reviewed. Finally, overall
reliability improvement and impact on the results of the
existing mill-wide safety compliance programs will be
summarized.
Index Terms – Risk Management, Electrical Safety
Program, Infrared Thermography, Molded Case Circuit
Breakers, Predictive Maintenance, NFPA70E Standard.
I. INTRODUCTION
A number of presentations from past Institute of Electrical and
Electronics Engineers (IEEE) Conferences and Electrical
Safety Workshops have focused on the reliability and
maintainability of molded case circuit breakers as a factor in
developing a credible facility safety program. Most certainly,
proper maintenance of any electrical product is necessary to
assure reliable operation. However, past assertions such as
“Several studies have revealed that circuit breakers that were
not maintained within a period of five years have a 50%
probability of failure” [1] and “If a breaker has not been
operated within as little as 6 months, it should be removed
from service and manually exercised” [2] and “Maintenance of
molded case circuit breakers is limited to proper mechanical
mounting, electrical connections and periodic manual
operation” [3] tend to be misleading. In actual practice, circuit
การแปล กรุณารอสักครู่..
