VFD on 240v Extractor Fan

Hi,

I am developing multiple projects but stuck on an issue.

I have a paint room with an attached filter and 240v extractor fan, similar to this:-

https://www.amazon.co.uk/Extractor-...tractor+fan+hydroponic&qid=1575542136&sr=8-13

I'm wanting to control it using my PLC with a VFD specifically the Siemens V20.

https://www.automation24.co.uk/variable-frequency-drive-siemens-sinamics-v20-6sl3210-5bb12-5bv1#

Would this be possible as to control speed its frequency i believe so only using 1 of the 3 phase outputs.

Thanks

In a word NO, the drive is 240v single phase input but 3 phase out & your motor is only single phase, the first problem is the inverter will detect two phases missing and probably alarm as well as many other problems.
Saying that, I came across this but there can be many pitfalls If it has a capacitor to start with.
https://www.youtube.com/watch?v=Lugrw8zbCEk

Shop around.

Some VFD's will control a single phase motor, but most won't as parky says above.

Big_Robo said:

Hi,

I am developing multiple projects but stuck on an issue.

I have a paint room with an attached filter and 240v extractor fan, similar to this:-

https://www.amazon.co.uk/Extractor-...tractor+fan+hydroponic&qid=1575542136&sr=8-13

I'm wanting to control it using my PLC with a VFD specifically the Siemens V20.

https://www.automation24.co.uk/variable-frequency-drive-siemens-sinamics-v20-6sl3210-5bb12-5bv1#

Would this be possible as to control speed its frequency i believe so only using 1 of the 3 phase outputs.

Thanks

Click to expand...

This was covered a while back (you can search yourself) and somebody suggested an inverter that would do single phase outlet but the consensus was they are expensive, unreliable and ultimately a compromise and if you can change to a 3 phase motor then do so.

Hi all, thank you all for the quick replies.

ah yes many problems indeed,

After seeing your messages I have found a few single phase VFD's a fair bit more expensive but nothing major. I only want a VFD as i can control the HMI remotely to either start/slow speed up/down.

Oh the joys.

It will depend on the type of motor
Split Phase motor is not suitable for variable speed.
Split Phase Capacitor Start motor is not suitable for variable speed.
Shaded Pole motor is suitable for variable speed but not reversible. Also inefficient.
Split Capacitor motor is also suitable for variable speed and can be reversible.
However, shaded pole and the split capacitor motors are used almost exclusively for fans or blowers. So be warned.

Here is the cheapest 1ph in 1ph out inverter on RS:
https://uk.rs-online.com/web/p/inverter-drives/1253238/

the_msp said:

Here is the cheapest 1ph in 1ph out inverter on RS:
https://uk.rs-online.com/web/p/inverter-drives/1253238/

Click to expand...

That link says:
"The Altivar Machine ATV320 variable speed drives are simple, yet enhanced machines. They have been designed for original equipment manufacturers and meet simple and advanced applications requirements for three phase synchronous and asynchronous motors"...

Then further down the page it says this in the specifications:
"For Use With Single Phase Asynchronous & Synchronous Motors"




I once tried to use a single phase "vfd" for an exhaust fan for a water plant lab and the result was poor. It was a situation where the operator was willing to risk a few hundred dollars on a trial to slow down the exhaust fan to about half speed.

I could not get it to work well below about 75% of full speed, and the drive showed a current draw of about 150% of what a clamp meter showed when running across the line. We used a 3/4 HP sized drive for a 1/2HP motor and it would still fault for overcurrent after a few minutes if we tried to slow it down too much.

In the end we suggested they get someone to crawl up in the attic and either alter the ducting to reduce the air flow or change the pulley mechanical ratio. The whole reason we tried this was to avoid disassembling this fixture to try to physically access the blower due to the way it was built into the room...it would have taken enough man hours to greatly exceed the price of our trial.

I think it is still running out there, but at about 80% full speed to avoid faults.

https://www.invertekdrives.com/variable-frequency-drives/optidrive-e3-single-phase/

At 80 W power consumption, why wouldn't you just let it run flat out and make life simple? That's less than an incandescent light bulb!

You might be able to use something simple such as a Analog Input Solid State Relay such as https://www.alliedelec.com/view/search?keyword=ssr analog part # RM1E40AA50 You can also download the datasheet on this website.



The data sheet says This relay is suitable for control of heaters, lighting and
slightly inductive loads such as small fans. The relay can also
be used for soft turn-on of high-power incandescent lamps.
I have not tried it yet but think you should be able to control the speed between 50 to 100%. It is going to do that differently than a VFD. There is no frequency change, it is just going to chop the sine wave to the percentage of the analog input. So it actually controls the output voltage of the waveform. The input can be 0 to 10 vdc or 0 to 20ma from a plc or using a rheostat.


You may also need a heatsink or mount it on a metal plate. I would expect heat generation to be minimal.



If you try it let us know if it works.

OkiePC said:

That link says:
"The Altivar Machine ATV320 variable speed drives are simple, yet enhanced machines. They have been designed for original equipment manufacturers and meet simple and advanced applications requirements for three phase synchronous and asynchronous motors"...

Then further down the page it says this in the specifications:
"For Use With Single Phase Asynchronous & Synchronous Motors"



...

Click to expand...

If you look at the wiring diagram, it is 3 phase output. Schneider did a ****-poor job of describing that drive; lack of attention to details.

parky said:

It will depend on the type of motor
Split Phase motor is not suitable for variable speed.
Split Phase Capacitor Start motor is not suitable for variable speed.
Shaded Pole motor is suitable for variable speed but not reversible. Also inefficient.
Split Capacitor motor is also suitable for variable speed and can be reversible.
However, shaded pole and the split capacitor motors are used almost exclusively for fans or blowers. So be warned.

Click to expand...

Bingo (except the last one should probably say "Permanent Split Capacitor" motor, aka "PSC"). Also Shaded Pole (and even some PSC) motors can be speed controlled with much cheaper methods than VFDs, i.e. "dimmer switches". Think of your overhead paddle fans.


The fans you pointed to use Blauberg motors. Blauberg makes 2 kinds of fan motors, EC (Electronically Commutated) which are inherently speed controlled, and regular AC powered, using PSC motors. That Amazon page is light on details (as per usual with Amazon) but judging from the price, it is not an EC version. If you insist on having an HMI that lets you program the speed, you can waste the money and buy the Invertek Drive mentioned by OkiePC, that's a good VFD designed for single phase output to PSC motors. It's just going to cost you 4 times the price of the fan itself...