Flexpak 3000 tachometer problem

Hello everyone

another question that may seen simple but I had a brainfart after a long night of working, and I cant see to figure out the problem.

I have a Reliance Electric Flexpak3000 DC drive installed, and trying to get to run. I have a Reliance Electric re-045 Tachometer installed on the motor, and I have the AC encoder kit installed on the drive and everything is wired correctly.

I have been over the programming, and parameters, as well as the jumper settings have all been checked, yet when I am running the motor, when I ramp up to 250rpm ( which should rattle this unit apart for the load attached to it) it runs at MAYBE 40 rpm.

I believe I have a scaling problem somewhere, however I can't seem to finger it out. my tach runs at 45v/1000rpm, and I have the jumpers 11 set to 31/125v according to the manual, and the High setting on jumper 14. I have zero'd the tach and armature voltage, and yet, I can't get it to run at the measly 34 rpm that I need.

I was wondering about the analog tach gain parameter (.750-1.125) and thinking that this might help with the problem, however not haveing a handheld tach to check is really hard guessing.

anyways, please help.

thanks

John

Why do you say it is a Flexpak3000 problem?

If the tachometer returns 45volts at 1000RPM then it should generate 11.25volts at 250RPM.

Does it? Don't you think this is important?
If you scaled the tach for some other range it should still return 1/4 the maximum output at 250 RPM
What analog input card takes 45volts for an input?
Do you know how to use a multimeter?

hi,

lemme rephrase. The tachometer is Rated for 45v/1000rpm. When I measured the voltage off the tach output wires when the drive was reading the motor running at 250rpm I got an output of 12.9Vac. now I realize that this is close (13% to be exact) to what it should be, but keep in mind that this system isn't meant to run above say 75 rpm.

When the drive was reading the motor running at 250 rpm, the actual speed of the motor was I would have to guess approx (40rpm or less). Now, having said that, this is the reason I believe that I am having a scaling issue. because it looks like my drive is reading my tach voltage as a higher output that it actually is. so. did I do my math wrong for max output dc voltage using their barbaric formula in the manual ((volts per 1000 rpm x max speed of motor) divided by 1000) all multiplied by 0.9 which gives me

(45v/1000rpm x 1750 rpm)/1000 = 78.75 x 0.9 = 71v.

The motor also lists 2 max speeds in the following format 1750/2000 rpm. would that be based on the different voltages? because the speed I have been using is 1750.

thanks again for all your help

John

Peter Nachtwey said:

What analog input card takes 45volts for an input?
Do you know how to use a multimeter?

Click to expand...

for the record sir, there is no reason do be a complete dick.
I am asking a question as I am having a problem. and yes, I know how to use a DMM. Probably better than you do, and you didn't seem to read my question properly before you went on a rampage.

all I need help with is trying to figure out why my motor is running at 40rpm and the drive is reading at 250 rpm when I have followed everything the manual from reliance has given me and this is my first installation of a drive like this.

so please, do me a favor a forgive me for not being as godly as you and knowing everything before I was born. I am sure you were learning at one point to, and someone had to give you advice. so please, if you don't have something constructive to say, please don't reply to my questions. I do not like being flamed.

thank you in advance to all those who choose to be helpful instead of just plain jerkish.

You may want to run the drive and motor in open loop mode first, and verify the scaling of the output voltage. It has been many years since Iworked with a Flexpak, so I don't recall their exact terminology for this or the parameters involved.

Also, check for problems with the field voltage and the wiring of the motor.

Once you can get the drive to run the motor at (or near) the correct speed, you should be able to measure the tach output and then try again to run the drive in closed loop mode.

Paul

You say you measure 12.9V at the tacho. 12.9V => 12.9/45*1000rpm => 286rpm. Your drive tells you that you are doing 250rpm. You believe that the motor is only doing 40rpm.

Forget the drive. There is no problem there. It has faithfully scaled 12.9V to read 250rpm. It is the damn tacho that if fooling you. If you are doing 40rom and you get 12.9V, either the tacho is defective or the rating plate is wrong.

well in my efforts of checking everything out, I found my one problem and thanks to all for the advice.

I have another question regarding the flexpak 3000.

does anyone know where in the parameters I would go to adjust the value the display reads to the user to a number that is reduced by a gear box?

and yes, I do believe that I would like a slap for being so dumb today, and I apologize again.

thanks

L0sts0ul said:

does anyone know where in the parameters I would go to adjust the value the display reads to the user to a number that is reduced by a gear box?


thanks

Click to expand...

Drive displays generally don't do that, and I know for a fact the flex pak 3000 can't do that. You could scale and wire an external display to an analog out on the drive to do what you want.

You have had two posts on here about drives, you seem to need some training in the basics. I worked in the pipe industry for years and with a lot of different drive systems and in your other thread I have no idea what you are talking about or trying to accomplish.

Calling out someone here with 3000 posts and more knowledge then 99.99% of the people in the controls industry is a good way to get ignored here FAST.

allscott said:

I worked in the pipe industry for years and with a lot of different drive systems and in your other thread I have no idea what you are talking about or trying to accomplish.

Click to expand...

I understand what you are saying. a couple of things first though.

with all due respect, I know the flexpak 3000 DOES display this information as I have the exact drive and revision installed on another of my lines in the plant. However, I cannot access the parameters on it until the line comes down, and it is not scheduled to be brought down for ateast another 45-60 days. The reason I Was asking here if anyone has done this is because after reading the manuals, and seeing the displays and how it works, not finding the solution is frustrating, hence the ONLY reason I would be asking here. I would not ask if I had only spent a few minutes on this problem.

I did not do the original install on the other line in this plant, and my manager is on vacation, and he left me to design, install and commission this drive and unit on my own. again I say, this is the FIRST time I have done this on my own. I am the only electrician in this plant, I have only the internet and my manuals for references, so Please, do try to understand.

finally, on your final statement. I did not call anyone out, if I hurt Peter Nachtwey feelings, then I apologize, or if anyone thought I was rude, please accept my apologies. however, I was flamed, and on a forum, no matter who you are, or think you are in whatever industry, you do not flame a peron on their 2nd post. especially when you no nothing about them or what they are doing other that the tidbits that are placed here. a personal message to call me an idiot would have sufficed. So, with all due respect, I am NOT an engineer, and I am working as hard as I can to learn as fast as I can, and I am learning fast, (you can't see what I have been through so far here).

I agree with you that I DO need some training, especially on the drives that I am working with most often, however my company is very cheap, and not willing to help out with the cost of training.

So again, I apologize if someone feels like I was calling them out, but to be honest, I Was the first to be "called out" and I did nothing but ask a question. I do not think the response was either professional or curteous.

thanks again for your advice.

Sorry, forgot one thing. You mentioned that you "were in the pipe industry for years" and did not know what I Was talking about. You are absolutely right, I may not be using terminology or proper descriptions that you are used to or used yourself, but I would appreciate the information you have from your years of experience and tools and tricks you have instead of telling me basically to take off.

Calling out was maybe not the right term. Let's just forget about that for now.

L0sts0ul said:

with all due respect, I know the flexpak 3000 DOES display this information as I have the exact drive and revision installed on another of my lines in the plant.

Click to expand...

I was wrong once before.....

Just to be clear, your motor is hooked to some sort of gear reducer and you want the display on the drive to show the speed after the reducer, correct?

It's been awhile since I worked on a flexpak. IIRC the display on these displays three things, Armature voltage, current feedback, and motor speed. I will download the software manual and get back to you.

Check your pm's

you are correct.

on the current installion that I did myself, it shows, motor speed, current, armature voltage, and preset speed (manual to say 250rpm).

on the OTHER drive, the motor is spinning at approx 235rpm (no tach avail, so I had to use a stopwatch, and a line) but the drive display (flexpack3000) show same output information but next to the speed it listed "40 SW RPM). This is where my question came from.

on the installion I did, yes, the motor is connected to a gearbox with a 17.36:1 ratio. hence the screwed up readings I Was getting earlier.

This "40 SW RPM" is the speed the gear box on teh second installation I did not do is moving the extrusion screw.

The OIM manual has info on how to scale the display. Publication D2-3344.

Just google reliance flexpak d2-3344 and look for OIM.

Good Luck

Similar FLEX 3000 Tachometer issue

I have similar issue with the Flex 3000 drive where the line that the drive is installed on runs for maybe 45-30 mins and then craps out with a TACHOMETER LOSS fault. All wire connections are verified and the tachometer was swapped out THREE times. I had no way of knowing if any of those tachs were valid to begin with but gave it a shot. Verified the PPR in the parameters as 600. I have a new tach on order. The whole situation is odd to begin with as line was only shut down for a simple maintenance routine and when they fired it back up on Monday we had this issue. Currently have the line running via ARMATURE FEEDBACK to get by.