Powerflex4 question

[jline1]

I'm new to the forum and have limited knowledge of PLCs and FReqDrives. I'm the only maint man where I work and need some info please. I have a newly installed machine with 3 AB Powerflex4 drives. The factory wired it with a switch that powers up a contactor. When the contacts are made, the frequent drives come on. I have to start each manually with green button on the front of drive. I want them to start automatically when powered up. Do I install momentary contact switches between 01 and 11 and also between 02 and 11 so when 02 and 11 are made they will start and come up to speed or do I have to Change a parameter setting. Thank you

 

[bright676]

Parameter P036 is the start source. It is probably set on 0 which is the terminal or manual setting. If it is already wired for auto set it on 2 or 3.
In the paper manual that comes with the unit there is a page with the basic start up parameters, check it out if you can.

 

[jline1]

Ok, that answer is way over my head.

 

[jline1]

There is currently a jumper between 01 and 11

 

[jraef]

Powering them up with a contactor like that every time is a recipe for early failure by the way. Bad design. All VFDs have what is called a "pre-charge" current limiting resistor that prevents the capacitor charging current from damaging the drive, then the resistor is shorted out a few seconds later so it doesn't over heat. Whenever you cycle power, it stresses that resistor just a little bit. Doing so EVERY time you want to use the VFD is going to make that resistor burn out sooner, and when it does, the drive dies in short order. Nothing on those small cheap drives can be fixed, so have some spares on hand.

Do you know what they were trying to accomplish by doing that?

 

[jline1]

No, I don't know what were trying to accomplish. I think the factory rep that wired the panel knew about as much as I do. I need to know what the parameters need to be set at. I need to know where to install the momentary contact switches. I think a normally open SW should be between 01 and 11 for STOP and another one between 02 and 11 for START. If that's correct what other parameters need changed. Remember please, I'm dumb as a rock on this subject. I've been reading the manual I downloaded from AB.

 

[Bering C Sparky]

I want them to start automatically when powered up.

I am going to have to side with jraef on this one, powering the line side of a drive with a contactor is not something you see normally. (or at least I haven't)

If you are dead set on having you machine power up on start in this configuration you can look at parameter A094 (Start At Power UP).
Then you will not need to add any additional switches or contacts.

However PLEASE be very careful and put some real thought into this before you do it, make sure there are no hazards that will come from this action.

If you look at the first page of the Quick start guide for the Powerflex 4 Quick Start Guide you will see a big ATTENTION WARNING regarding this parameter.
(See attached quick start guide at the bottom of this post)

What I normally do if a contactor is to be used is put the contactor on the load side of the drive and power the start I/O function off of an auxiliary set of contacts on the contactor.
This way when you call for run, the power contacts are closed before the drive starts to ramp up.
You will find folks that say its not good to put contactors on the load side of a drive also though.
But I personally would rather see it on the load side than on the line side, especially if you are cycling the drive on and off at regular intervals.

Good Luck and be SAFE.

BCS

Good luck.

 

[jline1]

Thank you for your reply but I think you misunderstand my position. I don't insist on Anything. The panel was wired by a contractor. I added a disconnect for lockout tagout. The way he had it wired was a panel with an overload inside that is switched on and feeds a contractor. There is a switch on front of panel that closes contacts and powers up the FDs. Ot is turned on ONCE in morning to start the conveyors. I have to go inside panel ea morning and manually start drives with touch pad. I want to have a start toggle switch on panel that will start the drives( 3) or stop them without opening the panel. I need to know what to set parameter P036 and how to wire the switches. I have little knowledge of this,,,I'm new. Someone else always did this where I worked for 19 years. They closed the plant and now I am somewhere else and on my own. Hoping someone here could walk me thru it. Thanks

 

[Bering C Sparky]

Right on,

But you said "you want them to start Automatically when they are powered up".

Correct me if I am wrong but now is sounds like you are saying you want to add a start and a stop button for each individual drive on the front of the panel to power on each drive separately.

If you just want the drives to come on when powered up then just set A094 to "1" and when the drive gets full line power it will start to run.

If you want to add start stop buttons to the front of the panel for each drive then you would just put a N/C momentary switch between terminal 1 & 11 for stop and then use a N/O momentary switch between terminal 2 & 11 for start.
Then change P036 to a "1".

There is a wiring diagram on page 5 of the quick start guide I attached on my last post.


BCS

 

[jline1]

By auto I meant I want to start the drives from outside the panel..sounds like I can follow your directions and get it done. Just don't want to make a mistake and burn up a drive. I don't have replacements. Small operation and very limited budget,. I told you I'm new at this. I'm a journeyman carpenter, certified welder on food grade stainless and a journeyman machinist...I'm a little outside my comfort zone here. Thanks again.

 

[Bering C Sparky]

Sorry for the delay getting back to you, we were doing sea trials so been very busy here.

Attached is a clear drawing for wiring your switches.

You will need to do this to each drive or at least provide individual contacts for each drive.

Then change P036 to a "1"

BCS

 

[rootboy]

The drawing that Bering provided you shows a three wire setup. To see what he is talking about, look at this document:

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/22a-um001_-en-e.pdf

And on page 1-16, at the top, you will not only see how to wire it, but that you will need to set Parameter P036 to a "1" as well.

 

[rootboy]

I am going to have to side with jraef on this one, powering the line side of a drive with a contactor is not something you see normally. (or at least I haven't)

We've done it. It was part of how we wired our Main and Standby drives on our lifts so we could use either VFD on either motor.

And yes, opening the line side contactor while energized makes a pretty blue spark. We made sure not to do that twice...

 

[jline1]

Thank you everyone, I think I got it. Can I wire all three drives to the same switches like the second diagram from top on page 1-16, ( 3 Wire SNK Control- Non Reversing. I assume they are set to (SRC) now, I'm not at work yet. I don't need reverse. Can you give me a brief definition of SRC and SNK? I tried Googling it but came up blank.thanks in advance.

 

[Tom Jenkins]

One of the reasons Allen Bradley VFDs are expensive is they insist on high levels of support from their distributors. I strongly suggest you get in touch with your local A-B supplier and ask them to come to your site before you implement any changes. There should be no charge for this. Depending on where in Illinois you are it is probably Revere Controls, and I have had excellent service from them in the past.