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Low voltage output from drive

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I replaced an ABB drive under warranty with a new ABB drive, (ACH550-UH-03A3-4), I did not perform the original startup. I can not gain access to the motor name plate data, but here is what was given to me. 460V/1.7A/1170RPM/60Hz/3ø. The problem is that when the drive is outputting 60Hz, (verified by two meters, and the display), the drive is only outputting ~224 Volts phase to phase, verified by two meters, plus the display). The DC buss, (per dislplay) is 667VDC. My first thought was the motor was wired for low voltage, but this motor has been running for about six months, and has been run in bypass. My next thought was that this maybe a fan wall style fan/motor, and needs to run faster than the namplate data of 60Hz. (I have run into this problem before), but he fan unit submittal is showing a speed of 1170 RPM at 60 Hz. Any other ideas?
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Welcome to ET.

Use the ET search function here, your problem looks familiar.
Look for a member Jraef he is great with drives.
If he isn't online right now, shoot him a private message.
We also love pictures, even 1/2 eaten donuts a worthy.
 

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Check the max voltage output setting in the parameters. Also check max out put speed. V/Hz. Ratio.
You're buss voltage sounds good for 460 volt applied, so its available.

Make sure you enter the correct motor data. You have a six pole motor and the drive needs to know this.
Call the motor manufacturer or go to their web site for the exact nameplate data.

This is very important. The first thing that should be done when installing a drive or motor or both.
 

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Discussion Starter · #4 ·
The output of the drive is set up for 460 volts, I have trippled checked the setup, and have had two other people verify the setup. Also, I forgot to mention, that when the output of the drive is disconnected, I then get 455 volts phase to phase, at 60Hz, which the display shows as well.
 

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Did you try and ring out the motor? I am not real familiar with ABB drives but this sounds like what happens with an Allen Bradley drive when it goes into current limiting, which is when the output current exceeds the hardware current ratings.
 

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Discussion Starter · #8 ·
The motor rings out fine, it also meggered greater than 2.2GΩs. Going back through the submittal, I noitced that the manufacturer of this unit says that the motor will produce .23 Hp. By the way this is a 1Hp motor. I have run into this before, with a fan wall, the motor name plate data on that application was 1770 RPM at 60Hz, and that drive showed low voltage as well, then I found out that the fan manufacturer, had set the unit up to opperate at 2393 RPM at 82HZ with these settings, the drive than put out 455 Volts. I'm thinking that this is the case here as well, I just can't get my head around why if the name plate data shows 1170 RPM at 60Hz, why it won't put out 460 volts?
 

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Discussion Starter · #10 ·
I replaced an ABB drive under warranty with a new ABB drive, (ACH550-UH-03A3-4), I did not perform the original startup. I can not gain access to the motor name plate data, but here is what was given to me. 460V/1.7A/1170RPM/60Hz/3ø. The problem is that when the drive is outputting 60Hz, (verified by two meters, and the display), the drive is only outputting ~224 Volts phase to phase, verified by two meters, plus the display). The DC buss, (per dislplay) is 667VDC. My first thought was the motor was wired for low voltage, but this motor has been running for about six months, and has been run in bypass. My next thought was that this maybe a fan wall style fan/motor, and needs to run faster than the namplate data of 60Hz. (I have run into this problem before), but he fan unit submittal is showing a speed of 1170 RPM at 60 Hz. Any other ideas?
.8 amps.
Would I be correct in assuming that in this application, that this is all the motor requires, so therefore this is all that is put out?
 

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6 pole motor. Does the drive know this? 1200 RPM. You are 100% confident all the motor data entered into the drive is exactly correct?

Have you measured the output voltage with motor loaded?

If you have 60 HZ and 460 Volts present at the motor ( you have verified the motor is indeed connected) than it should be running at base speed. 1200 rpm or thereabouts.
Is the motor connected correctly? 12 lead and six lead are easily ****ed up if the wrong guy connected it. Y or D connected.

This is a programming error IMO. The motor runs and is good. Right?

BTW. Where is our resident expert?
 

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I replaced an ABB drive under warranty with a new ABB drive, (ACH550-UH-03A3-4), I did not perform the original startup. I can not gain access to the motor name plate data, but here is what was given to me. 460V/1.7A/1170RPM/60Hz/3ø. The problem is that when the drive is outputting 60Hz, (verified by two meters, and the display), the drive is only outputting ~224 Volts phase to phase, verified by two meters, plus the display). The DC buss, (per dislplay) is 667VDC. My first thought was the motor was wired for low voltage, but this motor has been running for about six months, and has been run in bypass. My next thought was that this maybe a fan wall style fan/motor, and needs to run faster than the namplate data of 60Hz. (I have run into this problem before), but he fan unit submittal is showing a speed of 1170 RPM at 60 Hz. Any other ideas?
What was the original issue with the drive you replaced? What problems are you are having now that made you check the voltage output? What is the application of the motor and what is parameter 9902 (Application Macro) set for? Can you verify an autotune was completed on setup? Compiling a list of parameters that are not at the default setting would probably be the next step.
 

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at 2393 RPM at 82HZ with these settings, the drive than put out 455 Volts.
I am a little confused here but I am going to give it a go. The above motor was a four pole motor based on the following equation:

#poles= (f*120)/RPM
which would be (82*120)/2393 which is 4.11

can't get my head around why if the name plate data shows 1170 RPM at 60Hz
This is a six pole motor per above equation:
(60*120)/1170 which is 6.1

and has been run in bypass
What exactly is bypass? Was the drive bypassed and motor was ran thru a regular motor starter instead of drive?

The DC buss, (per dislplay) is 667VDC
This is correct based on:
Vpeak=Vrms * 1.41
Your line voltage was probably around 473 volts

460V/1.7A/1170RPM/60Hz/3ø. The problem is that when the drive is outputting 60Hz, (verified by two meters, and the display), the drive is only outputting ~224 Volts phase to phase, verified by two meters, plus the display).
Maybe I am missing something or as peewee said, one too many beers, but if the drive only has an output of 224 volts, it is only running at approximately 30 Hz.

I would wait for Jraef to respond....I am sure I probably screwed this up along the way....
 

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2 pole motors are 3600 rpm
4 pole motors are 1800 rpm
6 pole motors are 1200 rpm
8 pole motors are 900 rpm

So if the nameplate says its 1100 rpm, it is a 6 pole motor and no calculation is required.

The buss voltage is fine, so maximum output voltage is present and waiting for someone to tell it to run at 60 hz.

There is a possibility that this motor is connected wrong also. I know hooking up the wye connection will produce low current and full speed, but 1/2 the rated HP.
This usually burns up the motor before anyone realizes what is happening.
Then its found when inspecting the connections of the burned up motor.

If the drive is outputting the correct volts/hz ratio and the motor is running at half speed, I would open the peckerhead and make damn sure its hooked up right before I did anything more.

So my money is on a parameter mistake first or the motor is connected wrong, second.
 

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First off, most likely there is nothing wrong here. Your DC bus is correct, the motor is NOT overloading, so it is only your INTERPRETATION of the lower than normal voltage being an issue here.

When a drive is in "variable torque" mode, there is often a defaulted association with another energy saver feature that is akin to the other much maligned "energy savers" being pedaled put there. It's not that this technology doesn't work, it's just that unless the motor is seriously unloaded, it's not worth buying these things stand-alone. But on a VFD, it's a mo-cost feature, so why not?

What it does is monitor the total kW required by the load, and if it is low, it automatically reduces the magnetizing current going to the motor by reducing the relative RMS voltage. This also reduces the torque, but if the motor is not overloading, it doesn't need the torque. So as long as the motor is unloaded, you will not see the normal voltage at the motor terminals, because the motor doesn't need it and the drive knows that. If you increase the load, the relative voltage will pull into line.
 

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First off, most likely there is nothing wrong here. Your DC bus is correct, the motor is NOT overloading, so it is only your INTERPRETATION of the lower than normal voltage being an issue here.

When a drive is in "variable torque" mode, there is often a defaulted association with another energy saver feature that is akin to the other much maligned "energy savers" being pedaled put there. It's not that this technology doesn't work, it's just that unless the motor is seriously unloaded, it's not worth buying these things stand-alone. But on a VFD, it's a mo-cost feature, so why not?

What it does is monitor the total kW required by the load, and if it is low, it automatically reduces the magnetizing current going to the motor by reducing the relative RMS voltage. This also reduces the torque, but if the motor is not overloading, it doesn't need the torque. So as long as the motor is unloaded, you will not see the normal voltage at the motor terminals, because the motor doesn't need it and the drive knows that. If you increase the load, the relative voltage will pull into line.
I agree. I thought he took his measurements under load? I also thought he said the motor was running at half/reduced speed with 60 HZ showing on the readout?
I should go back and read all of this thread again I guess.

Similarly, I had a customer call about drive over voltage some years ago.
I went to the plant and found nothing wrong.
He had the drive on the bench and was testing it.

Once he realized there was a buss and this buss could provide enough power to over speed the motor, it clicked for him.
Funny as I heard less and less from him over the years.

He finally got it. Made sense of it. I guess?
From then on it was just orders and not so much hand holding. :thumbsup:

Todays controls can do so much more. Glad you popped in.
 

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2 pole motors are 3600 rpm
4 pole motors are 1800 rpm
6 pole motors are 1200 rpm
8 pole motors are 900 rpm
.
guess that applies to NEMA MOTORS only.
however mostly this part of the world we use IEC MOTORS AND
2POLE MOTORS ARE 3000 RPM
4POLE MOTORS ARE 1500 RPM
6POLE MOTORS ARE 1000 RPM
8POLE MOTORS ARE 750 RPM
 
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