Published X/R Ratios

[Grouch1980]

Because the MFG did not provide you with any literature to state you can use a CL fuse to raise your SCC rating in combination with the CL fuse you are Helically Wound.

What do you mean by 'helically wound'?

Assume your SCC at the unit is 4.7K and your calc yields an X/R of 2.
Local 10K rated OCPD.
Here I would say you now must use your MF adjustment to see if you fall below 5K...I leave the math to you.

Not following... so you're saying to calculate the MF adjustment at the unit. What text X/R ratio am I using at the unit?

The equation is MF = (I asym @ X/R calculated) / (I asym @ X/R tested).

I use the calculated 4.7k and x/r of 2 to calculate the numerator.
I use the tested 5k and x/r of what?? to calculated the denominator?

And then I run the same calculation at the OCPD serving the unit you're saying, further upstream from the unit?

 

[MyCleveland]

What do you mean by 'helically wound'?

Not following... so you're saying to calculate the MF adjustment at the unit. What text X/R ratio am I using at the unit?

The equation is MF = (I asym @ X/R calculated) / (I asym @ X/R tested).

I use the calculated 4.7k and x/r of 2 to calculate the numerator.
I use the tested 5k and x/r of what?? to calculated the denominator?

And then I run the same calculation at the OCPD serving the unit you're saying, further upstream from the unit?

Your first ?…You have a tool box full of things that end with DRIVER. Now delete the driver and add ed.
Reference was where you have equipment installed and the AFC is above its rating and you can do nothing to fix it.

Recall I stated I was not sure my advice was sound.
No one commented on the examples or added any advice on how to address a situation of adjusting the AFC for a high X/R ratio.

If you have been following other thread about using CL fusing to address equipment with low SCCRs…I made an attempt to contact UL and even register on the web site but they are asking for info I cannot provide.
My goal was to look over some equipment product standards to see if they have an assigned X/R for various SCC values…5k, 10k, etc.

I was making an assumption that for a given SCC value I could use the same X/R values from the table 1 for OCPDs.

I believe your question needs addressing but cannot give you an answer.

Are you willing to try an communicate with UL on this?