Search Results: 'time overcurrent'
The Relay Testing Handbook #6: Testing Overcurrent Protection (50/51/67)
Ships in 3-5 business days.
Modern relays have very different characteristics that require a different testing philosophy to ensure that they will operate when required. The Relay Testing Handbook: Testing Overcurrent... More > Protection (50/51/67) provides step-by-step procedures for testing the most common overcurrent protection applications.
This volume is designed to help you understand and test: Instantaneous overcurrent protection (50); Inverse time overcurrent protection (51); Directional overcurrent protection (67).
Each chapter explains the following topics for each element with realistic, practical examples and detailed instructions: Understanding the application; Determining which settings are most important; Recommended steps to correctly plan, perform, and evaluate pickup tests; Recommended steps to correctly plan, perform, and evaluate timing tests; Preventing interference from other settings inside the relay; Tips and tricks to overcome common obstacles. Go to http://valenceonline.com for more information.< Less
The Relay Testing Handbook: Principles and Practice
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This hardback book includes most of the volumes in the The Relay Testing Handbook series and includes: Electrical fundamentals; Relay testing fundamentals; How to translate digital logic used by... More > relay manufacturers into familiar concepts; and Best practices for creating and implementing test plans.
Entire chapters are dedicated to the most commonly used protective elements including: Overvoltage, undervoltage, and frequency (59/27/81); Time, instantaneous, and directional overcurrent (51/50/67); Simple and transformer differential (87) testing with three or six current channels; and Line distance (21) testing using realistic test plans to minimize setting changes.
Each protective element chapter includes: A description of operation written for a relay tester, not for a design engineer; Step-by-step test techniques that maximize your effectiveness and efficiency; Realistic examples from various relay manufacturers and models.
Go to http://valenceonline.com/ for more information.< Less
Ships in 3-5 business days.
In the US, almost all technical exams on electrical works are based on the NEC. However, the NEC book itself is a 1500+ pages mega size monster. You just won't have the time and energy to go through... More > and memorize everything in there. Even though the exam may allow you to use the code book, looking up a particular item can be very time consuming and you may run out of time real quick! This is why we come up with this study product - we provide you with essential knowledge and information that can be easily comprehended so that during the actual exam you won't need to browse the code book for answering every single question!
Officially, the N19 exam covers these:
General Knowledge and Calculations
Utilization Equipment and Devices
Motors and Controls
Wiring Methods, Materials, and Conductors
Grounding and Overcurrent Protection
Special Occupancies, Systems, and Equipment
In any case, the examination requires that you have a working grasp of the National Electrical Code.< Less