Emerson Commander SK strange behavior

[karnalta]

Hello all,

I am facing an issue with my Commander SK that I cannot solve on my own, I am struggling on it since several days

The really basic setup to produce my problem is :

- Pr 05 set to Pad (keypad mode).
- Terminal B2 bridged to B4 to always Enable the drive.
- Pr 35 set on AtSpeed instead of the default ZeroSpeed.

This should normally set the Digital Output terminal (B3) to ON when drive is at asked speed. But, on a fresh power on, the output still behave like it is on "ZeroSpeed", so it's ON at idle and OFF as soon as drive start to spin.

If I simply press once the STOP/RESET button on the keypad, output start to work as intended (at speed) without issue. But, at next power off / power on of the VFD, it still bug.

ATM, each time I power up the machhine I have to press once the STOP/REST button for my VFD to behave as intented..

Anyone have a clue on what's my problem ?

Thank a lot.

 

[DarrylR]

Pr 35 is actually menu item 8.41 (digital output control: terminal B3). 0 is default for zero speed. Should be set to 1 for at speed (At.SP). Then menu item 8.21 must be set to 10.06 for at speed. Default is 10.03 for zero speed.

 

[karnalta]

Pr 35 is actually menu item 8.41 (digital output control: terminal B3). 0 is default for zero speed. Should be set to 1 for at speed (At.SP). Then menu item 8.21 must be set to 10.06 for at speed. Default is 10.03 for zero speed.

Thank you for your reply.

As you explain, it seem there is two menu to set when using the CTSoft software from Emerson.

But, I set parameters using buttons on the VFD, I don't have the serial cable. And in theses parameters, there is only one to set and it is PR35.

Am I wrong ?

 

[DarrylR]

Initial drive power up default setting for parameter access is L1 (level 1) Basically menu 0 items only. You need to enable level 2 access by setting parameter 10 (I believe) to L2. You can then navigate the different parameter menus from the keypad. LEFT and RIGHT arrows to change menu, UP and DOWN arrows to change which parameter number you wish to select within the selected menu. Lastly, if you do make changes you need to finish by setting your selected menu's parameter 0 to 1000 to save.

 

[karnalta]

Initial drive power up default setting for parameter access is L1 (level 1) Basically menu 0 items only. You need to enable level 2 access by setting parameter 10 (I believe) to L2. You can then navigate the different parameter menus from the keypad. LEFT and RIGHT arrows to change menu, UP and DOWN arrows to change which parameter number you wish to select within the selected menu. Lastly, if you do make changes you need to finish by setting your selected menu's parameter 0 to 1000 to save.

I do have set PR10 on L2 (even L3 in fact) so I have access to PR35 and have set it on At.SP already. After a powerup, if I go into the settings, PR35 is still on At.SP, that seem OK. But the behavior it self, only work after having pressed STOP/RESET button as explained in my first post.

However, I am not aware of that "setting your selected menu's parameter 0 to 1000 to save". Parameter on the VFD start at PR1 which is minimal frequency.

 

[DarrylR]

It is a bit confusing. If you're not changing the menu # and navigating directly to parameter 35, all you're doing is setting menu 8/parameter 41. That's what menu 0/parameter 35 is. You also have to go to menu 8 (L/R keys) parameter 21 (U/D keys) and set it to 10.06. After that go to parameter 0 (still in menu 8) and enter 1000 in order to save the change.

 

[DarrylR]

This may help if your keypad only has the up and down arrows

 

[karnalta]

This may help if your keypad only has the up and down arrows

I will try this tomorrow, it will allow me to change advanced parameters without the software.

I hope it will work. I wouldn't have found this by myself.

Thank you.

 

[Gene Bond]

The drive keypad only has up/dn buttons. The remote keypad has left/right to access the higher menus.

I've never run into this, but it sounds like it might be a firmware bug.

There is a note, that if Pr12 is not set to diS, then Pr35 can not be used.

First, I would try holding the red/stop button down for 5 seconds (let's the drive know who's boss). Then cycle power. If it fixes it, go have a beer.

If not, then go to the upper menus:
Set P10 to L3
Set Pr35 to USEr
Set Pr71 to 8.21
Set Pr61 to 10.06
Press M to get back to Rdy
Hold red/stop button for 5 seconds

Test & cycle power and test again.

Good luck. The SK is pretty solid, but like a lot of devices, sometimes you have to beat them into submission.

 

[karnalta]

I am getting back at it a bit late but I have been re-wiring my machine from scratch.

Now that I am back at this problem, it's gone... It work as expected.

So the problem was probably a wiring issue or some kind of reset problem as suggested by Gene Bond.

Anyway, thank you all for your help !