You can find some of the most common digital relay problems before you even set foot on the job-site. Collect all of the documents related to the relay and compare what they have in common. Does everything match up? If not, you may need to find out which one is correct before you can start testing. The earlier you find the problems, the less time you’ll spend waiting for answers.
Click “Mark Complete” below after watching the video so you can keep track of your progress.
The slide of the Overcurrent Coordination Plot , both curves refer to North American Curves. Nevertheless the comments refer to IEC Vs IEEE curves, and not North America Vs IEEE (Because both are the same).
Thanks. Please post timestamps to help fix issues.
Unfortunately a coordination study is rarely seen on the job site when we are testing relays. I am lucky to see a 3-line and or 1-line. I am not sure who to ask to get a copy of the study. I will be asking in the future.
Thanks
Great news! You don’t get what you don’t ask for. If there are arc flash stickers, then there is a coordination study and those arc flash numbers are meaningless if the coordination studies don’t match the actual relay settings.