ABB HVAC drive question

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rulito

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Eagle Pass, TX
Hello, sorry my bad english

Wanted to use a frequency drive for reduce speed on a blower fan (40 hp, 49A).

Saw a deal, $450 for a 40 hp ABB ACH550-VC-0519A-4+F267.

I noticed there is a "HVAC" drive.

Question is

Can i use this HVAC drive for my application? I just want to lower the rpm manually.

Regards!!
 
What do you mean by lower the RPM manually?

Do you plan to vary speed as heat/cool demand varies - if it varies?

If you change the rate of air flow through a heat exchanger when the amount of heat produced by the exchanger is not changing you may cause overheating - it was presumably designed to move a specific amount of air over a specific BTU output. If the amount of BTU output can be varied then it more reasonable to change the airflow to match the BTU output. You should find that a single stage fixed BTU heat application will require a fixed blower speed, but a heat pump or cooling unit may be able to have the speed varied depending on current BTU output.

If you want to make a fixed speed change for some reason, it would cost less to do so with a change of pulley sizes for belt driven blowers. But a VFD is about the only choice if direct drive blower. I say this because you said "lower the RPM manually".
 
Thanks for your response!

Lower rpm manually, i mean to decrease the Hz from the panel, maybe to 40-42 hz. Its a direct drive blower. I dont want to vary the speed if the heat/cool demand varies.

I run a food protein pilot plant and just want to decrease or increase the speed motor to test the effect on my research. This blower is the only device i want to control. I dont have heat pumps or coolling unit. Its just a exahust fan on a drying chamber with no other devices. Just want a fixed speed change. Saw this drive cheap, but i dont know if in order to connect this VFD to my blower fan i we any need other devices to close the loop.


Regards
 
Thanks for your response!

Lower rpm manually, i mean to decrease the Hz from the panel, maybe to 40-42 hz. Its a direct drive blower. I dont want to vary the speed if the heat/cool demand varies.

I run a food protein pilot plant and just want to decrease or increase the speed motor to test the effect on my research. This blower is the only device i want to control. I dont have heat pumps or coolling unit. Its just a exahust fan on a drying chamber with no other devices. Just want a fixed speed change. Saw this drive cheap, but i dont know if in order to connect this VFD to my blower fan i we any need other devices to close the loop.


Regards

The need for other equipment depends on design of the drive, and other environmental conditions. You may or may not need line reactor on input and or output of the drive, you may need to run different raceway/cable if there is RF problems using the existing conductor/cable, you could even need to deal with harmonic issues on the supply side in some cases - though I think you generally need a much larger drive then you will have for that to be a common issue.
 
The HVAC industry on the whole is notoriously cheap. Drives marketed to that industry as HVAC drives are usually stripped down versions of standard drives. For the vast majority of applications, they work just fine. Most of the features that have been removed are not needed for most applications even outside of the HVAC market.

At the price you mentioned, I wonder if it is used.
 
The HVAC industry on the whole is notoriously cheap. Drives marketed to that industry as HVAC drives are usually stripped down versions of standard drives. For the vast majority of applications, they work just fine. Most of the features that have been removed are not needed for most applications even outside of the HVAC market.

At the price you mentioned, I wonder if it is used.

Yes it is used. Its on ebay http://www.ebay.com/itm/281546390986?_trksid=p2059210.m2748.l2649&ssPageName=STRK:MEBIDX:IT

Regards
 
A motor is a motor. The drive does not care what your application is.
Technically correct, but in reality, there is a "numbers game" played in the drives industry when it comes to drives for CENTRIFUGAL loads, which are comprised of some types of pumps and fans, and you will find those used predominantly in the HVAC industry.

On a centrifugal load, the power DEMANDED by the load (the pump or fan) from the motor varies at the cube of the speed change. So for example, at 50% speed, the pump/fan will only require 12.5% of the HP from the motor as it would at full speed. Since the motor must be sized for the worst case scenario, full speed, that means the VFD must be sized for that as well.

But in VFD design, there is an overload capacity factor that must be built-in to each VFD, to allow it to accelerate, or more importantly RE-accelerate a load after a singificant change. So a VFD used for something like a conveyor is typically designed to handle 150% of its rated current for up to 60 seconds.

When you use a VFD on a CENTRIFUGAL load such as a pump or fan, another aspect of that load it that the load ITSELF cannot change that fast, plus, if the motor is sized for the maximum flow at full speed, it CANNOT be overloaded anyway. Therefore, the added overload capability of the VFD is in essence wasted. So a long time ago, the VFD mfrs, in conjunction with special rules from testing authorities like UL, allowed the VFD mfrs to rate the output motor size for CENTRIFUGAL loads at a higher value than they would for any other type of load. That means that a VFD sized for a 30HP heavy duty load can be used on a 40HP centrifugal load. That special sizing rule however does away with most of the overload capability, since it is not likely to be needed. So a centrifugal load drive, often referred to as a "Variable Torque" drive, will only be capable of 105-110% overload for 30 seconds. Since those loads are most often found in HVAC applications, they are referred to as HVAC drives.

Then too, such as with ABB, since HVAC applications almost never need some of the more advanced control features found in heavy duty drives, the mfrs take cost out of them by not including those. The HVAC industry is notoriously cheap, so even a dollar in cost can make a difference.

So can this work for a "blower"? Probably, as long as it is not a positive displacement type of blower (the word blower is too vague). If it is an exhaust fan, it's about a 99% chance it is a centrifugal blower and that drive will work fine.

A word of caution on buying used drives from FleaBay; if a VFD has been sitting idle and unpowered for more than a year, you must do a procedure called "capacitor reforming" to avoid having your money wasted when it destroys itself in short order. Google that term, there re plenty of instructions on doing that, but the best practice involves using a variable transformer, something you likely do not have. So let the buyer beware.
 
A word of caution on buying used drives from FleaBay; if a VFD has been sitting idle and unpowered for more than a year, you must do a procedure called "capacitor reforming" to avoid having your money wasted when it destroys itself in short order. Google that term, there re plenty of instructions on doing that, but the best practice involves using a variable transformer, something you likely do not have. So let the buyer beware.

Thanks!, yes its a centrifugal exahust fan.

We will do capacitor reforming Thanks for the advice
 
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