Relays are more than a collection of protective elements to be tested, as most test plans assume. The logic settings are as important as the protective elements and deserve the same treatment we gave the general settings. The logic settings don’t stop at physical inputs and outputs either. We should test everything this relay is supposed to do to make sure it will work correctly when required.
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At 5:27, did you mean to say LT1? Not LT2?
Good eye. Yes, you are correct, that should be LT1.
Hi,
I’m trying to work along with the video series. I have a SEL-311L P/N 0311L15CC325X4XX. Is it compatible with your 311C settings? I think 311L has a few more bells and whistles. Tried the file download link but ended up with the settings in a text format/web page. I was expecting an RDB file.
It depends on the options in your 311L. if it came with backup protection, then you should be able to use the settings. Can you post the file name of the file you tried to download so I can find the topic. There’s no download link in this topic
Sorry,
Link was from video before this one. Here is the link :
https://valence.relaytraining.com/wp-content/uploads/trth-os1/downloads/TRTH-IT-B-OS-1-1-2.RDB
I watched all the videos first and now I’m going back through with my test set and an SEL 351. Looks like there was a change from 311 to 351?
Good eye. We’re only dealing with overcurrent elements, so you should be able to covert the settings to any relay. Let me know if you need help.
Great courses Chris. At 30 secs I noticed the logic for ULTR is not 51P “OR” not 51G but it should be “AND” I believe. Also that is what you say during the discussion is AND. Thanks again. James
Thanks for the comment. It is OR and that’s how I’ve seen it in all relays. I do incorrectly say AND in the video at the 45 second mark. The trip will unlatch if the phase current is below the setting OR the ground current is below the setting.
In the logic setting for 51GTC (time 2:48), what does 32 stand for? Did you say direction? I listened many times but still didn’t quite catch it.
The technical definition of 32 is directional power relay, but SEL uses it internally as a directional element.
Why does the unlatch command utilize the 51s instead of the 50s? I’m pretty new with this.
Good question.
The unlatch logic is looking for current to go away to prove that the circuit breaker opened. The 51P is always lower than the 50 pickup, so if the current is below the 51, the 50 can’t be picked up.