Had identical situation with a Graham drive many many years ago. It's called "cogging". Called the drive guru out to take care of it. I have no idea what he did. Whether he replaced a component or the whole drive. I have not heard from them since.

At least you now have a name for it.

Can you calll ABB tech support?

 

You can see this in the belts when the wrong program is chosen (although it has been running for 3 months as you said). Try a different program besides hvac and see what happens then check the parameters on the hvac program to see if they've changed from default.

 

Had this same problem on a graham vfd, graham explained to me that outputs would close and open and create like a single phase condition . once we changed out the main board the problem went away.

 

we have had probs in the past on tower fans with vibrations and power faults... when the building installed the drives they wired in on the load side of the contactor...as to keep the orignal start stop and just run the analouge... it was the contactor on the line side that was the problem... we always try to power the drive directly from the breaker or fuse block... having the a contactor on the line side is just a weak link... certain programs can run rough though.... hope that helps.

 

What were the E-3's doing? Did you get specific faults or were they random? How are they controlled? Having a control circuit that is earth grounded is not good on the Toshibas. I'm not really familiar with the ABB but if they use a floating delta transformer having a earth grounded control system could possibly cause problems.

 

You mention your at a "facility". If this is a large facility and you have dirty power with allot of harmonics than this can cause havoc on VFD's and they will do all sorts of crazy things. Does your facility go through allot of ballasts and or replace allot of fluorescent lights? If so then thats a pretty good sign you have harmonics present. I've seen it where one facility was creating the problem and it affected other people miles down down the power grid.

 

Carrier ABB VFD

out of curiousity, what system was it, air handler or rooftop unit or chiller?
where was the VFD mounted, was it in the controls/compressor compartment or in the blower compartment? do you happen to have the ABB part number (I see the model number, wondering if you had to order a special NEMA enclosure). THANKS!

 

Never had a problem with ABB.
I'm thinkin harmonics also. If you don't have a power quality meter, try a true RMS one.

 

is there a rectifier for the vfd ?

 

I've actually seen these drives run with a blown line side fuse and limit themselves on current, at about 40 hz. I have never seen the "cogging", except on across the line motors where we lost a phase way up the line and was showing low on one incoming phase.

 

Have a look at the load side wiring including any bypass involved. I had one, quite new, a while back, where it would single phase the motor intermittently and end up tripping the vibration switch on a cooling tower from the shuddering. Turned out to be a bad connection at one of the contactors in the bypass.

 

Couple Helpful pointers.

Well I can try to help you out as I am a Engineer for ABB at the factory.

First one thing caught my eye that several mentioned is Harmonics. This is not entirly true with what was being said. Harmonics are caused by VFD's since they have Diodes which conduct current in a non-linear method. Drive manufactors add Reactors or DC Chokes that limit the harmonics generated by the drives. All ABB drives come with 5% Reactors so this is not typically a concern unless your facility has a large amount of VFD'S on a single transformer. I am talking like more than 33% of the transformer load is VFD'S. Some of the tell tale signs of Harmonics is Constant speed motors running very hot, Transformers running Hot, Nuisance burning out of magnetic Lighting ballasts and nuisance Circuit Breaker Tripping. IN my years working for a manufacture of VFD'S I have only seen two occurances of Harmonics, It happens rarley.

What you are seing is possibly the VFD was not properly set up for the motor it is running. When you enter the motor nameplate datd into the drive under the 99 group, it will perform a ID run on the motor and learn various characteristics of the motor. I would receomend running this again for the motor, this can be done by changing parameter 9910. I would also verify that all motor nameplate data has been entered correct.

A VFD can operate a three Phase motor while being single phased with no problem. As the drive is converting AC to DC and then back to a simulated AC sign wave. If it is being single phased on the input of the drive the tell tale sign would be an over current trip on the input power.

I am guessing by your explantation that this has a carrier bypass unit installed. Unfortunatly we do not have anything to do with the design and manufacture of this unit. I belive it is a standard classic bypass with contactors and a control power transformer. If there is a low voltage situation or a single phase situation this control power transformer can cause relay chatter on the drive output contactor and will cause the motor noise.
ABB Manufactures the Eclipse bypass which contains a Switched Mode Power Supply that will keep the 460 V VFD running well below 370V. thats over a 30% voltage drop compared to many other drives 10%.

Another possibility could be a resonation condition in the drive with the capicitors in the drive if you have power factor correct capacitors in the electrical system in your building. If this is the case there is some tuning you can perform on the drive to help. Does the VFD'S have any TCI or MTE type harmonic filters?These also contain capacitors and can cause tuning issues.

Then there is the possibility of a resonation condition of the motor and equipment at a certain frequency, this is typically apparent in cooling towers with large fans and not so much small fans. You can troubleshoot this by putting the drive in Hand mode and changing the speed slowly unitil you have the condition. Then skip past that speed and determine if it goes away? When this is occuring look at the keypads values for the DC bus voltage and current. If they are jumping around it could help me out.

As with anything electrical, do not work on the equipment unless you have received training and are authorized to perform said work. Always follow published saftey information in the manuals and follow local, state and NFPA codes for your saftey.

Hope this helps,

Jeff

 

Well I can try to help you out as I am a Engineer for ABB at the factory.

First one thing caught my eye that several mentioned is Harmonics. This is not entirly true with what was being said. Harmonics are caused by VFD's since they have Diodes which conduct current in a non-linear method. Drive manufactors add Reactors or DC Chokes that limit the harmonics generated by the drives. All ABB drives come with 5% Reactors so this is not typically a concern unless your facility has a large amount of VFD'S on a single transformer. I am talking like more than 33% of the transformer load is VFD'S. Some of the tell tale signs of Harmonics is Constant speed motors running very hot, Transformers running Hot, Nuisance burning out of magnetic Lighting ballasts and nuisance Circuit Breaker Tripping. IN my years working for a manufacture of VFD'S I have only seen two occurances of Harmonics, It happens rarley.

What you are seing is possibly the VFD was not properly set up for the motor it is running. When you enter the motor nameplate datd into the drive under the 99 group, it will perform a ID run on the motor and learn various characteristics of the motor. I would receomend running this again for the motor, this can be done by changing parameter 9910. I would also verify that all motor nameplate data has been entered correct.

A VFD can operate a three Phase motor while being single phased with no problem. As the drive is converting AC to DC and then back to a simulated AC sign wave. If it is being single phased on the input of the drive the tell tale sign would be an over current trip on the input power.

I am guessing by your explantation that this has a carrier bypass unit installed. Unfortunatly we do not have anything to do with the design and manufacture of this unit. I belive it is a standard classic bypass with contactors and a control power transformer. If there is a low voltage situation or a single phase situation this control power transformer can cause relay chatter on the drive output contactor and will cause the motor noise.
ABB Manufactures the Eclipse bypass which contains a Switched Mode Power Supply that will keep the 460 V VFD running well below 370V. thats over a 30% voltage drop compared to many other drives 10%.

Another possibility could be a resonation condition in the drive with the capicitors in the drive if you have power factor correct capacitors in the electrical system in your building. If this is the case there is some tuning you can perform on the drive to help. Does the VFD'S have any TCI or MTE type harmonic filters?These also contain capacitors and can cause tuning issues.

Then there is the possibility of a resonation condition of the motor and equipment at a certain frequency, this is typically apparent in cooling towers with large fans and not so much small fans. You can troubleshoot this by putting the drive in Hand mode and changing the speed slowly unitil you have the condition. Then skip past that speed and determine if it goes away? When this is occuring look at the keypads values for the DC bus voltage and current. If they are jumping around it could help me out.

As with anything electrical, do not work on the equipment unless you have received training and are authorized to perform said work. Always follow published saftey information in the manuals and follow local, state and NFPA codes for your saftey.

Hope this helps,

Jeff

I love this forum. Thanks Jeff

 

I like ABB drives they tend to be very intolerant to line voltage or motor problems I would look at the mechanical I have seen blowers with "bad spots" as far as HZ or rpms are concerned. If you can put the drive in manual and increase HZ till vibration occurs then continue till vibration subsides some field balancing may be required or perhaps you can reset min HZ to avoid this problem.

 

Good point! Is motor inverter duty?

 

I have also seen this where a drive was setup for 50 hertz instead of 60.

 

Cooling tower tecnology

Does anyone out there have any advice or knowledge about copper ionization of water in a cooling tower in order to eliminate chemicals being added to the system?

 

Check what ur minimun hertz setting is. If im not wrong Trane keeps their VFD's at 22 hz?? Cant remember have to go and check. But what ABB Tech is saying makes sense- check ur parameters, one by one, by one, bye one.........so on and so forth

 

Yes many times... need in line filter for incoming power..also have seen the new ABB take out bearing electrically.. worked with factory - installed drives in 2 different buildings - took motors out in one and not the other. get the factory involved they have been working on this issue for the last year on our site.

 

i have the abb ach 400 vfds and th ra vfd keeps going out on over voltage and i cant clear it any suggestions

 

The bearing issue mentioned is a totally different phenomanon. There is not allot known yet by it in order to prevent it of fix it on the drive level. The best advice is to install Aejis shaft grounding brushes to disappate the current. This is caused by common mode voltage caused by the PWM waveform and this can be enhanced by poor grounding habits by the VFD, Motor, Equipment and facility. Grounding Grounding Grounding I cant express it enough.