There's still tens of thousands of them around in service in old factories and (shockingly) substations around the US. If no one learns about them we'll be screwed when all the old guys retire!
Hey the adjustment for the toc pick up is not the drag magnet it is the spring adjustment. The drag magnet adjustment is for the time setting. In the event that the time dial setting needs to be finely adjusted you move the drag magnet. The instruction manual explains this.
Thanks for your comment. First off, I should have done a better job discussing this in the video and plan to make a part 3 to cover this. From tweaking hundreds of these in the past, both the magnet AND spring adjust both the pickup and timing to some extent. #1 the spring is easier to make fine adjustments, whereas a 1/8" movement of the magnet changes the characteristic drastically. #2 when considering the tolerance bands we're looking at, it seems to be easier to bump the low end of the curve (2xTAP) into calibration using the spring without pushing the pickup result out than vice versa. If either test fails by a small percentage, I start with the spring and can usually get everything dialed in. If the fast end of the curve (>6xTAP) is out of spec, it's likely at that point you'll need to move the magnet to get the high end dialed in and then adjust the spring to correct the slow end after. Just what I've found though, and your mileage will vary. And it's important to test the pickup AND curve against after tweaks which I didn't demonstrate in the video.
The IFC is newer (from the 70's I think) functionally identical, except it's physically smaller, has a plastic/phenolic case instead of metal, and they have a 2 position tap adjustment allowing each unit to have a larger number of pickup positions. All of the same testing steps apply, though double check the book for the tolerances and wiring connections!
Awesome information ! thank you for this video. It's difficult coming by good resources such as yours!
I'm happy to help! I love doing this.
@@testingtechtips THAT IS AWESOME!!! I really appreciate you at the moment!! 👍
I didn't think anyone cared to learn about these old relays anymore. Thanks for sharing the knowledge!
There's still tens of thousands of them around in service in old factories and (shockingly) substations around the US. If no one learns about them we'll be screwed when all the old guys retire!
our utility systems surprisingly still uses a handful of these. I was designated to conducted testings on them just now.
Thank you so much for this. I really want to learn more and more about these relays since we are struggling big time
Glad it was helpful!
I hear some AvE in that intro, good content. Thanks for all of the info, newbies like me really need this sort of stuff :)
Glad to help!
Hey the adjustment for the toc pick up is not the drag magnet it is the spring adjustment. The drag magnet adjustment is for the time setting. In the event that the time dial setting needs to be finely adjusted you move the drag magnet. The instruction manual explains this.
Thanks for your comment. First off, I should have done a better job discussing this in the video and plan to make a part 3 to cover this. From tweaking hundreds of these in the past, both the magnet AND spring adjust both the pickup and timing to some extent. #1 the spring is easier to make fine adjustments, whereas a 1/8" movement of the magnet changes the characteristic drastically. #2 when considering the tolerance bands we're looking at, it seems to be easier to bump the low end of the curve (2xTAP) into calibration using the spring without pushing the pickup result out than vice versa. If either test fails by a small percentage, I start with the spring and can usually get everything dialed in. If the fast end of the curve (>6xTAP) is out of spec, it's likely at that point you'll need to move the magnet to get the high end dialed in and then adjust the spring to correct the slow end after. Just what I've found though, and your mileage will vary. And it's important to test the pickup AND curve against after tweaks which I didn't demonstrate in the video.
what is the difference between 12IFC and 12IAC relays?
The IFC is newer (from the 70's I think) functionally identical, except it's physically smaller, has a plastic/phenolic case instead of metal, and they have a 2 position tap adjustment allowing each unit to have a larger number of pickup positions. All of the same testing steps apply, though double check the book for the tolerances and wiring connections!
Where is your link for reading TOC Curves?
ruclips.net/video/3o6jNp7KVkM/видео.htmlsi=PP9s7cLUWjzsE3QC around the 20 minute mark