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- Inspection and maintenance - Collect and record identifying nameplate data, construction, design, ratings, and components. Compare to project plans and specifications. Perform mechanical services and control component services necessary to assure device operates as intended. Adjust and lubricate as required.
- Important IEEE Standards
- IEEE C37.06 AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis-Preferred Ratings and Related Required Capabilities (ref. Table 8)
- IEEE C37.13 Standard for Low-Voltage AC Power Circuit Breakers Used in Enclosures
- IEEE C37.95 Guide for Protective Relaying of Utility-Consumer Interconnections
- IEEE C37.100 Standard Definitions for Power Switchgear
- 3 Critical Lubrication Points for Power Circuit Breakers Lack of lubrication is the number one problem test technicians run into when servicing circuit breakers in the field.
- 4 Methods of Medium-Voltage Breaker Design The four common mediums used to extinguish an arc during breaker contact separation are Oil, Air, Gas, and opening in a Vacuum.
- Critical Maintenance for Circuit Breakers [PDF] This paper discusses common maintenance problems and mistakes for circuit breakers and how to correct them.
- Circuit Breaker Lubrication in the Field [PDF] The clearing time and operation of the circuit breaker is strongly dependent on the quality of its lubrication.
- Medium-Voltage Circuit Breaker Maintenance [PDF] Medium-voltage circuit breakers, breakers for systems with voltages of 2.4 to 38 kV, have maintenance procedures that will vary based on construction of main contacts and mechanisms used to operate these contacts.
- Asymmetrical Interrupting Current Rating of Medium-Voltage Circuit Breakers [PDF] The asymmetrical current is an important component of the total fault current. It is critical that not only the symmetrical interrupting current but also the circuit breaker total interrupting rating be greater than the system worstcase available fault condition.
- Lubrication and Circuit Breakers Choosing and applying the correct lubricant to circuit breakers, while often overlooked, plays a key role in the proper maintenance of electrical distribution equipment.
- Glossary of Circuit Breaker Terms Quick reference of over 150 circuit breaker terms and acronyms.
- SF6 Circuit Breaker Cheat Sheet SF6 has a number of advantages for use as an insulator. The dielectric strength of SF6 increases with pressure so smaller breakers can be used at higher voltages.
- Important IEEE Standards
- Testing - Apply insulation, vacuum integrity, gas, liquid, contact, timing, time-travel, operational, interlock, control, and other tests as applicable.
- General Circuit Breaker Testing
- 10 Critical Tests for New Power Circuit Breakers The following checks and tests should be performed at a minimum to ensure that a new low voltage circuit breaker is ready to be placed into service.
- 5 Often Overlooked Tests for Power Circuit Breakers Periodic inspection and testing of power circuit breakers almost always includes a visual inspection, calibrating the overcurrent protection, contact resistance and insulation tests, but how often do you perform these other important, and often overlooked, checks and tests?
- 3 Basic Electrical Tests for Medium-Voltage Circuit Breakers It's essential that circuit breakers be tested and maintained to ensure proper operation during electrical faults.
- A Guide to Testing High Voltage Circuit Breakers [PDF] This document will help readers to understand what is involved with keeping circuit breakers operating at peak performance.
- Vacuum Integrity
- Testing for Loss of Vacuum in Vacuum Interrupters [PDF] A frequently-asked question is "How can I tell if my vacuum interrupter has lost vacuum?"
- Vacuum Interrupters — How They Work [PDF] This article covers the features of the vacuum interrupter and how they correspond to the ability of the interrupter to perform according to its ratings.
- Vacuum Bottle Technology and Testing [PDF] Unlike interrupters that use oil or gas as the interruption medium, vacuum interrupters have contacts that are designed to work under vacuum.
- Vacuum Interrupter Testing Using Magnetron Atmospheric Condition (MAC) Test Equipment Vacuum interrupter testing utilizing MAC testers can provide a viable means of determing the condition of vacuum interrupters prior to failure. Using condition based predictive maintenance inconjunction with MAC tester data, trend to failure of vacuum interrupters can be predicted.
- Contacts/Current Path
- Contact Resistance vs. Millivolt Drop [PDF] Why the difference in the test results?
- A Guide to Low Resistance Testing [PDF] Understanding and Measuring Low Resistance to Ensure Electrical System Performance
- Operational/Interlock
- MV Circuit Breaker Control Schematic Explained A quick look at a typical medium-voltage circuit breaker control scheme with an explanation of important components.
- Circuit breaker safety interlock systems explained Drawout circuit breakers are equipped with safety interlock devices that are required by various Industry Standards and Certifying Authorities.
- Kirk Key Application Scheme Book In order to lay out complicated interlock schemes, it is necessary to understand the simplest applications. In this book, both basic and advanced concepts of interlocking are outlined and discussed.
- Other Circuit Breaker Tests
- Integral Ground-fault Field Test Procedure [PDF] Paragraph 230-95(c) of the National Electrical Code (NEC) requires that all ground-fault protection systems be performance tested when first installed.
- Power factor testing for circuit breakers Circuit breakers are designed to interrupt either normal or short-circuit currents. This paper looks at the various different types of circuit breaker and how to test them.
- General Circuit Breaker Testing
�Getting Started