What are the best methods to test drag chains? After doing some testing, I’m finding it difficult to get a consistent and accurate test setup. Does anyone have a reliable method?
Current Test Setup. I also varied the number of links touching the floor.
Also, I found this, https://www.esda.org/assets/Documents/Drag-Chain-Presentation-from-MDA.pdf, figured it’d be helpful for anyone else who hasn’t seen this.
The test method outlined in the picture is resonable. The results are the problems with drag chains making contact with the floor. Not sure if it is the drag chain or the floor at this point. If the floor is in the high resistance range, it makes it more difficult to overcome the contact resistance between the floor and the drag chain.
Heavy and longer drag chains have a better chance of making contact.
“Heavy and longer drag chains have a better chance of making contact.”
We’ve been noticing that ourselves. We’re also finding that the Link-to-Link resistance is very high with the two types of chains we have on site. Do you happen to have any recommendations on a type of chain to use?
I don’t have any recommendations. In my previous job we used conductive wheels on mobile equipment and hard wired fixed equipment.
We found the same issue as you are finding that drag chains we not reliable.
That being said, there are orginizations that I have been to that make drag chains work. I do not know what they used as I just measured the connection to ground.
Anybody else?
Like John, we use conductive wheels on mobile equipment and hard wired fixed equipment. Some sites tried drag chains & asked for tests, which I carried out. The drag chains attempted were never reliable and we do not use them.
For most of my career leading ESD Control programs, we specified conductive wheels for mobile equipment used on ESD floors. For other mobile equipment we had a hard wire connection and a connection point on a stationary workstation connected to facility ground
