# VFD Question



## GSH (Sep 24, 2009)

I have an application where I am using 2 Baldor Vector drives and I am trying to start the drives remotely and then use the keypad to adjust speed. These are the older ZD18H.... drives. The drives will start but with no speed reference (desired RPM is at 0). When I try to use the keypad to adjust speed, nothing happens. I have the drive set up for Standard Run but do not see anywhere in the manual to set up a remote start and local speed reference. Anyone familiar with how or if this can be accomplished?

Thanks


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## JRaef (Mar 23, 2009)

GSH said:


> I have an application where I am using 2 Baldor Vector drives and I am trying to start the drives remotely and then use the keypad to adjust speed. These are the older ZD18H.... drives. The drives will start but with no speed reference (desired RPM is at 0). When I try to use the keypad to adjust speed, nothing happens. I have the drive set up for Standard Run but do not see anywhere in the manual to set up a remote start and local speed reference. Anyone familiar with how or if this can be accomplished?
> 
> Thanks


Generally, VFD command and control is divided into two separate sets of programming functions:


Where is the Run / Stop command going to come from?
Where is the Speed Reference going to come from?
But if I remember correctly, this Baldor drive (which I never liked) does not totally separate these functions like almost all others do. I think that if you put it in Remote Start/Stop command mode, it ONLY allows a speed command to come from the analog inputs, not the keypad. Then if you put it in Keypad control, you don't have a 3-wire remote start-stop capability. Silliness.

What we did however, is use it in Keypad control mode, then used the "Enable" input as a virtual Run command by hard wiring the remote Stop command input. The issue was, if you wanted 3-wire control you had to make it externally with a control relay and use a relay contact as the Enable command. Again, silly...

Make sure you enable the keypad Stop control by the way, I think it's dangerous to have a Stop Key on the Keypad that does not stop the drive.


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## GSH (Sep 24, 2009)

That was what I was afraid of. I have a lot of experience with Baldor drives and also AB. (AB is by far a more versatile and reliable drive) I have never had an application like this where I needed to contol speed from the keypad with remote start, but I figured it would be simple:laughing:! WRONG. I have the Enable, Stop, and Run Forward signals all coming in at the same time when a lever is pulled and a limit switch makes. I know the run forward is momentary, but I didn't think it would be a problem if it was maintained. I do have the stop button enabled on the keypad as well. By doing this the way you recommend, I would need to set the drive for Keypad control and just energize the enable circuit? This would mean that I would also have to press the FWD button on the drive and set desired speed, right?


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## John Valdes (May 17, 2007)

Baldor makes a keypad extension cable up to 100" long. Will that be long enough? Just remember you are in either remote or local on the Baldor control. When in local, the keypad is the operator. When in remote mode, the J1 terminal strip is used to connect inputs and outputs. You must pick one or the other. (enable and stop functions can be considered)

Why do you have to use the keypad? The remote function enables the terminal strip J1. This in turn allows speed control of several varieties from remote locations. You cannot use local and remote setting simultaneously. You must select one or the other on this drive.

Edit: The keypad extension cable comes in lengths up to 200'. 501 catalog number CBLHH305KP is the 30.5 meter cable (100') The numbers represent the distance in meters.


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## GSH (Sep 24, 2009)

I am familiar with the extension cable for the keypad. Good suggestion though. This application is for a machine that is used to bore engine blocks. The owner of the machine has 2 more just like it. They are controlled with AB drives and work with remote start and keypad speed control. I think he got a deal on these two Baldor drives and that's why he wants to use them. I know I can put a POT on the drive, but in an effort to try and copy the operation of the other 2 machines, I thought I could set these up the same way. I will install a POT if that's what he wants or change the drives. The decision will be his. I just wanted to make sure there wasn't a way to do the same thing with the Baldor drives before going to plan B. Thanks for all the advice!!


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## JRaef (Mar 23, 2009)

Here's an idea then, set the Control to be like an MOP (Motor Operated Pot). I think Baldor called it something like E-pot (Electronic Potentiometer). It allows you to have a pair of inputs like push buttons that give you "Up-Down" speed commands just like on the keypad. That can be used with an external Start/Stop circuit. Combine that with a digital display of the analog output scaled to be speed and you have a virtual keypad as far as an operator goes.

Or use the remote keypad... LOL.


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## John Valdes (May 17, 2007)

The keypad extension cable was a first designed for mounting of the keypad to the outside or from the inside of the enclosure door. To bring the keypad to the front.
Remote is not always far away. Remote mounting of the keypad is needed for some applications.
They did not have longer cables than 100' when I was using the control. I kept a 100' one with me on service calls as it made my job much easier. Being able to have the keypad in your hand while you were somewhere besides next to the drive was nice.


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## RobRoy (Aug 6, 2009)

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