Molded case circuit breakers operate reliably in countless
industrial settings, and when properly applied these devices
are designed to safely protect distribution systems for many
years. In some cases, previous accounting of performance
and reliability of MCCBs has been inaccurate, at times
resulting in confusion for the engineer attempting to apply
these devices properly.
Like any electrical component, ongoing maintenance of
MCCBs is an important element in assuring these devices will
perform as designed, protecting distribution systems when
called upon to do so. Existing standards such as the NEMA
Standards Publication AB4 and IEEE Standard 1458 serve as
useful guides in identifying routine maintenance procedures
that will prolong the life of these devices.
The paper mill in Longview, Washington has maintained a
very effective predictive maintenance program via use of
thermography to identify when a MCCB should be removed
from service and replaced. In the aggregate, field decisions to
remove a breaker from service are generally validated by
factory testing after the device has been removed. Although
there will be some error in making this choice strictly based
upon a thermal survey, even a few wrong decisions have still
resulted in very reliable overall performance of MCCBs within
this facility.
VIII
Molded case circuit breakers operate reliably in countless
industrial settings, and when properly applied these devices
are designed to safely protect distribution systems for many
years. In some cases, previous accounting of performance
and reliability of MCCBs has been inaccurate, at times
resulting in confusion for the engineer attempting to apply
these devices properly.
Like any electrical component, ongoing maintenance of
MCCBs is an important element in assuring these devices will
perform as designed, protecting distribution systems when
called upon to do so. Existing standards such as the NEMA
Standards Publication AB4 and IEEE Standard 1458 serve as
useful guides in identifying routine maintenance procedures
that will prolong the life of these devices.
The paper mill in Longview, Washington has maintained a
very effective predictive maintenance program via use of
thermography to identify when a MCCB should be removed
from service and replaced. In the aggregate, field decisions to
remove a breaker from service are generally validated by
factory testing after the device has been removed. Although
there will be some error in making this choice strictly based
upon a thermal survey, even a few wrong decisions have still
resulted in very reliable overall performance of MCCBs within
this facility.
VIII
การแปล กรุณารอสักครู่..
![](//thimg.ilovetranslation.com/pic/loading_3.gif?v=b9814dd30c1d7c59_8619)