[uspl]

Hi all

This has been kicked around and and I have seen various answers but..
I am currently running a 10k pot setup as per http://www.woodworkforums.com/attach.../190119.attach

I can vary between 16k RPM and 24k RPM but no lower than 16k. Can someone explain the math on this as far as using the pot as a voltage divider and getting speeds down to say 8k or 9k?

Would simply changing to a 20kOhm pot do the trick ?

Thanks

David

[underthetire]

No. 10k is correct, you need to adjust the minimum frequency parameter, and the parameter for low speed of the pot. If you don't have the manual I can look it up.

[uspl]

Thanks for the super quick response.
I have the manual here, from what I can work out it is Pd70 and Pd72 and Pd73 that I need to play with, correct ?

70 = 0
72 = 400
73 = 0

right now.

[Web Goblin]

Yes those parameter settings should give you 0-10volts on the pot and vary the frequency between 0 and 400Hz.

[uspl]

Yep, thought I was right.
Trouble is, IT DOESN'T WORK !!!:boxing:

I can get between 16000rpm and 24000rpm but no lower than 16.

I spent all day on this yesterday, cannot work it out.
The pot varies the speed perfectly as long as I don't want to go lower than 16k

Please help, any suggestions appreciated.

[Web Goblin]

Can you check what PD011 is set to?

[uspl]

Hi

Pd011 is also zero, I have played with various settings for both 11 & 73 as per previous posters on this subject suggesting they both had to be right.

I did find something strange, my manual shows 72 as the lower limit and 73 as the upper ??

[Web Goblin]

It does seem odd that it wont work. Just out of curiosity does the inverter already have a pot on the front of it and are you adding an extra one away from the inverter?

[Web Goblin]

Another setting you can check is PD027 for the starting frequency. This should be set to 0.5. Cant see this being the problem but it would be worth checking.