[How do I?] Reading The Wiring Schematic - Potentiometer Symbol

Shiseiji

Avid destroyer of many materials.
H-M Lifetime Diamond Member
Joined
Sep 14, 2014
Messages
428
Hi all, TIA. I'm wiring in the pot on my ABB VFD and I'm not certain what the potentiometer symbol is telling me. Can't find anything similar and it obviously doesn't look like either the European or US typical symbol . . . I pasted in the lower table as it's on another page in the manual and AI1 isn't defined anyplace I can find. Must be obvious to someone, just not me.

For AI, darned if I can figure out which connection is the wiper. Is that a solid state pot?
For AI1 I "think" it's +10v to the pot, wiper to the AI and the full on terminal of the pot to ground. But I don't know what that gray bar above the wiper connection is . . . shielding? Again, thanks.

upload_2015-5-22_14-1-15.png

Ron


upload_2015-5-22_14-1-15.png
 
The schematic is a little confusing. It shows a 4-20 ma source as the default speed control input.

For using a pot, use the optional example to the left of the main drawing.

There should be a UI dip switch or jumper that needs to be set to the U position.

SCR = Screen/cable shield
The pot wiper goes to AI (Analog Input)
One leg goes to GND
The other leg goes to +10V
 
It is a 10k potentiometer, but it does not specify the type. Some are straight linear, some have tapers more suited to audio applications. I haven't looked at all the VFD's I've seen, but it seems more use the linear. Jim, or someone, please correct me. I'm brain dead from product testing yesterday, failure analysis and re-design. Have a lot of thoughts swimming through fog. There was a dramatic improvement, but it still fell short of hoped and needed (and halfway expected, for me at least). So, now back for another pass through engineering then I'll try again.

The taper is not super super critical for testing, and they are cheap if you can't find the right one, just get any 0-10k. Main difference would be how the last 1000 ohms or so is tapered. It might not give you as fine of control as you want on that end of the scale. It everything works, replace with the proper one st your convenience.
 
The schematic is a little confusing. It shows a 4-20 ma source as the default speed control input.

For using a pot, use the optional example to the left of the main drawing.

There should be a UI dip switch or jumper that needs to be set to the U position.

SCR = Screen/cable shield
The pot wiper goes to AI (Analog Input)
One leg goes to GND
The other leg goes to +10V

Jim, thanks! I was pretty sure after hitting [Send] that by writing out the question I was on target, but it's good to know what SCR stands for. And I know exactly where the UI dip is at.
Tony It is a linear, not the speaker type the name of which escapes me at the moment. And I have it on hand and and mounted, thanks to Amazon or the 'Bay, can't remember.

Both of you, thanks. I appreciate the re enforcement that the schematic is a little weird. The 10k note is one I pasted in from someplace else in the manual. Got home from work, here are the answers, and the garage awaits!

Best wishes to all, please take a moment on Monday to remember those who had their check cashed while serving. Uncle held mine for 27 years befor I got it released.

Ron
 
The pot wiper goes to AI (Analog Input)
One leg goes to GND
The other leg goes to +10V

...and if the maximum speed is at the wrong end of the control just reverse which end goes to GND and +10V.

-brino
 
What are the slanted symbols with little tag ends crossing the three leads to the pot? Does that indicate that the leads are to be isolated? I.E. and opto-isolator?

Vlad
 
What are the slanted symbols with little tag ends crossing the three leads to the pot? Does that indicate that the leads are to be isolated? I.E. and opto-isolator?

Vlad
It looks like the they are specifying the wiper wire with a separate shield that is then connected to the rest of the shield at the VFD connection. I've never seen it drawn like that before. I think a normal shielded cable would work fine.

PS: the audio pot is a logarithmic taper.
 
What are the slanted symbols with little tag ends crossing the three leads to the pot?

For what it's worth, I took this:
shield.jpg
as indicating the shield tied to ground.

And these:
length.jpg
as indicating that the wires may be quite long, that is, that you could mount the pot. remotely from the controller.
In fact that's probably why they shield it, someone could route those wires thru an area with high switching currents that could cause noise on the signals.

Note it also looks like they are saying tie the shield to the SCR (signal cable shield) as well as to ground.

-brino
 
1st; running fine! Need to play with the macro settings now, but the hard part is mostly over. Still want to wire a NO proximity sensor in series with the stop loop so it won't run unless the chuck key is in it's place. Best I can tell I'm going to have to use it to close a relay. Happen to a couple kicking around from a "I'm a gunna." project that's dropped way down on the list and will work on the 24v just fine..

- brino On the pot wiring: Had checked it prior to soldering it up, still managed to do it wrong so resoldered it last night to keep the color coding consistent.

Jim - Thanks. I had read it while researching what to get, obviously retention is getting to be an issue LOL.

-bino On the SCR, thanks, that part I got, and was done.

Appreciate the additional education on the schematic. Right now the start/stop, reverse (still to be wired up and the macro set), and pot are only 8" from the VFD, 90 degrees to the left of the lathe on the wall. They'll be moved later when I've played some and have an idea for what's comfortable. But it gave me the bigger buttons.

Ron
 
Back
Top