speed controlling a vortex?

[stonergirl]

I read these posts and I am still confused. I have a 5" vortex fan that I'd like to slow down due to the noise. What type of controller would be safe and not have the hum??

 

[Sundance]

I read these posts and I am still confused. I have a 5" vortex fan that I'd like to slow down due to the noise. What type of controller would be safe and not have the hum??

Speedster - set to variable

 

[Silver Oak]

You'll get the hum from a Speedster. At least I have with both a Fantech inline and the S&P TD-Mixvent

And as far as my post being condescending to Imnotcrazy, that's definitely the pot calling the kettle black.

In all seriousness, I think Imnotcrazy is correct in general: you need to know specifically what type of motor is in your fan, and that will tell you whether you can use a Variac or not.

 

[Outportgrower]

WTF???????????????
"Mr.My Grow is @ "The Off-Grid Place"
U have ALL this running on 2 wind turbines & some Car Batteries?
I sure would like to see a Pic?
Of this Battery Bank?
............O and wait U told me U R and "Electrical Engineer" by trade?​

So Y don't U just make what U need?​

Go back to your donkey, that was then this is now. Try staying off your Mommy and Daddies putter before they beat you again. Only children have sig lines like yours.

I could put one together, but why bother when it is cheaper to buy it off the shelf? Makes no sense what-so-ever to spend anymore than needed.

And you wanting to know the address where this is located, get a life!

 

[MRJackHerrer]

I gave up talking to the idiots in this thread many months ago imnotcrazy. they are just going to do it however they want to anyway despite proof otherwise but thanks for the well researched (cited even) and thought out points on this subject. some people you just cant reach.

 

[habeeb]

The jet engine analogy is pretty close. Unless someone has a great quick fix to muffle the sound of rushing air without cutting performance too much I am all ears, well eyes anyway.

get a box bigger then the fan, like 12 X 12 inch. get pro muffling foam and line the box, then get fantech silencers on both ends and it will sounds as quiet as a kitten purrr

you have to make sure and get the fantech silencers on both ends as the box will not muffle the sound , like only 50%

I did this and my ostberg rated at like 650cfm and it sounds like a light light light hum,

 

[SB7]

Ok, one more question for the EE's in this thread.

I realize that for a PSC motor the line line freq/poles will determine the rpm.
Reducing the input voltage ( variac) will reduce the output torque, and that the rpm will be determined by the intersection of load torque and output torque curves.

It has been stated previously that these types of motors are constant wattage type, and as such will draw more current as the input voltage drops. Ie draw more current than the windings are rated for.

So I did did some measurements with my vortex ( PSC )and a variac ( The motor appears to be Swiss in origin and looks to be the same motor used in most of these type of fans.. Fantech, Elicent, Vortex etc.)
Measured with a Fluke 87 and also with a power consumption meter. Both produced the same results, in addition , the motor RPM ( measured with a Photo Tachometer/Strobe) was not affected by the measurement tools. )

Input 120 V,A & W 120Vac ,1.1A = 132W
Input 90 V,A,&W 90Vac, 0.88A = 80W
Input 60 V,A & W 60Vac, 0.77A = 46W ( shouldn't it be drawing 2.2A ? , of course, if it were, it would have the same output torque as at 120Vac but as it's rpm has dropped considerably, it doesn't have the same output torque and isn't drawing more current )

Doesn't seem to behave the way it is expected ?
For the record, I can't find any mention of impedance protected windings, rather it is thermally protected, which would imply that it ISN'T impedance protected as it requires a thermal breaker to protect it during a stall ...

Why does the Vortex/variac behave this way ?


I should note in case not everyone is aware, that some S&P's are shaded pole motors and some are PSC's so it's up to the user to find out which one they have.

 

[DrBudGreengenes]

Go back to your donkey, that was then this is now. Try staying off your Mommy and Daddies putter before they beat you again. Only children have sig lines like yours.

I could put one together, but why bother when it is cheaper to buy it off the shelf? Makes no sense what-so-ever to spend anymore than needed.

And you wanting to know the address where this is located, get a life!

Ya really need to STOP posin...
that is not yours and U know it..
Where did the trees come from we can all see thru the window?

​

 

[RockyMountainHi]

I read these posts and I am still confused. I have a 5" vortex fan that I'd like to slow down due to the noise. What type of controller would be safe and not have the hum??

Do a search on eBay for "AC or DC ELECTRICAL MOTOR VARIABLE SPEED CONTROL TOOL"

It will get you several of these:
http://cgi.ebay.com/AC-or-DC-ELECTR...emQQptZLH_DefaultDomain_0?hash=item2c5136b7ad

Works great on my vortex 750


http://cgi.ebay.com/AC-or-DC-ELECTR...emQQptZLH_DefaultDomain_0?hash=item2c5136b7ad

 

[Outportgrower]

I feel so special. I have my own 12 year old troll who is on the ignore list now..

Besides the comments from the peanut gallery from someone that would have no need to use an in-line fan with CFL's, a proper speed controller and filter combination will drastically decrease the sound you are able to hear if you run a vortex inside a cab. To add even more control over the amount of rushing air leaving the exhaust, a box and the use of a non-metal based (tin-foil) ducting at the exit will also lower the noticalbe sound in a room.

 

[Outportgrower]

Ya really need to STOP posin...
that is not yours and U know it..
Where did the trees come from we can all see thru the window?

​

So sorry you are not able to see to the left of the second white building. Get back to your donkey, he misses you.

You know you have people jealous when you have your very own troll, or they are a cop looking for directions.

 

[America]

The speedster/router speed controller works fine! Although it isn't a perfect controller, I haven't noticed them degrading the operation or the life of any of my fans. Best bang for your buck, and it isn't big, cumbersome, and unnecessary like the variacs.

In this thread I've read of potential fires and electrocution. Why bother? lol

Just use the speedster..

 

[freeride high]

http://www.acehardwaresuperstore.com/ace-full-range-slide-fan-control-p-91026.html
any reason not to use this? mine works great!

 

[DrBudGreengenes]

So sorry you are not able to see to the left of the second white building. Get back to your donkey, he misses you.

You know you have people jealous when you have your very own troll, or they are a cop looking for directions.

Dood U own a Poorly Build (note sagging roof)
House and a Garage in a SUB-Division
Just cause U pulled the Meter...
That Not "Off-Grid"
You son R smack tab in the middle of it
Power Lines and phone lines
R
In all yur Pics,...
U R A Bullshitter​

 

[skulquake]

I MUST reiterate my reply in your original thread: You are going to cause grow-room fires eventually in someone's grow-room by supplying this PATENTLY FALSE INFORMATION

ANY electrical device requires the proper WATTAGE to do the operation it was designed to do. Wattage= Volts x Amps

By using a Variac to reduce the voltage that the fan motor "sees" the fan will pull MORE current to provide the same WATTAGE.

The problem inherent in doing so: these fans were designed to operate at 120Vac, usually at some menial current (0.68Amp for my Fantech FX6").

Reducing the voltage can increase the current draw to the point that the motor windings OVERHEAT, thereby causing the potential for a FIRE...

Also, the problem with reducing voltage and NOT varying the supply FREQUENCY is there is an inherent LOSS OF TORQUE; IE: you are OVERLOADING THE MOTOR. which increases SLIP of the motor. When you increase Slip, the motor will continue to pull more and more current to provide the necessary torque. The motor current will continue to increase until the motor, OR Variac windings (like in your original thread) BURN OUT creating a Short Circuit.

The Diac fired Triac controls are the proper way to control these fan's speed, it even states on my Fantechs that I should use KB Electronics Part # KBWC-15K Which is a Solid-State Traic based speed control.

References:

From: http://www.ehow.com/how_5114264_use-variac.html
A variac is not a motor speed control; don't attempt to use it on an AC motor. Most variacs, at the maximum knob setting, will output over 120 volts. Use caution when making adjustments; high voltages can damage equipment. Some older variacs lack a grounded outlet. Use caution when plugging equipment into these.

From: http://www.eng-tips.com/viewthread.cfm?qid=200189&page=48
Sigh... Oh well...

Speed of an AC motor is ALWAYS determined by the supply frequency and the number of poles in the motor winding.

Changing the voltage without changing the frequency reduces the TORQUE of an AC motor by the square of the voltage. So for instance at 60% voltage, the torque is .6 x .6 = 36% of the normal torque. If you have a fixed load, the speed reduces because the motor now has insufficient torque to keep it spinning at full speed. DEPENDING ON THE MOTOR DESIGN, that may or may not work out too well, because MOST AC motors will try to keep running the same speed and pull more current to do it, until the motor burns up.

A variac or rheostat (a.k.a. dimmer) can change the speed on SOME TYPES of motors because they have a type of design that inherently limits the current flow, thus allowing the lower torque output to occur without burning themselves up. These are called Shaded Pole motors and most likely your fan is one of these if it hasn't burned up from your test. Another type is a "Universal Motor" which is really more of a DC motor to which you supply AC. This is what you find in small appliances and portable tools, not likely on a fan.

A VFD changes the voltage AND frequency together at a predetermined ratio, which allows the motor to maintain a constant torque while varying the speed by keeping the ratio the same as it was at full speed and full voltage. But it does so by converting the AC to DC, then using high speed transistors to fire DC pulses in what is called a PWM pattern to the motor to recreate a "pseudo sine wave" that the motor reacts to AS IF it were AC. This works great on 3 phase motors. The problem with most types of single phase motors is that the pulsed DC is incompatible with the design of the motors, and you can damage the motor, the VFD or both. Usually both.


From: http://isefaq.com/ActiveKB/questions.php?questionid=2
Can I vary the speed of my motor with a variable transformer?

Many motors can use a variable transformer for speed control.

Motors that usually can be controlled by varying the motor voltage:
Universal Motors
Series Wound Motors
Torque Motors
Shaded Pole Motors

Motors that sometimes cannot be varied by changing the motor voltage:
Split Phase Motors
Permanent Split Capacitor Motors (Imnotcrazy's added NOTE: 99% of inline fans are of the Permanent Split Capacitor type)
Repulsion Induction Motors
Motors with centrifugal switches

Motors with fan cooling can sometimes be damaged due to the decreased cooling effect at lower speeds (depending on load).

So imnotcrazy do you still experience the hum with the solid state controls. You've mentioned how safe they are but I believe want everyone wanted to know was did the hum disappear like with a Variac?

 

[attackyhi]

i have here activeair blower 600cfm, how to control this fan? seems its diffrent from elicent or others.. can use http://item.rakuten.co.jp/styledesign/1881g/　this one or not?

 

[amargas]

I MUST reiterate my reply in your original thread: You are going to cause grow-room fires eventually in someone's grow-room by supplying this PATENTLY FALSE INFORMATION

ANY electrical device requires the proper WATTAGE to do the operation it was designed to do. Wattage= Volts x Amps

By using a Variac to reduce the voltage that the fan motor "sees" the fan will pull MORE current to provide the same WATTAGE.

The problem inherent in doing so: these fans were designed to operate at 120Vac, usually at some menial current (0.68Amp for my Fantech FX6").

Reducing the voltage can increase the current draw to the point that the motor windings OVERHEAT, thereby causing the potential for a FIRE...

Also, the problem with reducing voltage and NOT varying the supply FREQUENCY is there is an inherent LOSS OF TORQUE; IE: you are OVERLOADING THE MOTOR. which increases SLIP of the motor. When you increase Slip, the motor will continue to pull more and more current to provide the necessary torque. The motor current will continue to increase until the motor, OR Variac windings (like in your original thread) BURN OUT creating a Short Circuit.

The Diac fired Triac controls are the proper way to control these fan's speed, it even states on my Fantechs that I should use KB Electronics Part # KBWC-15K Which is a Solid-State Traic based speed control.

References:

From: http://www.ehow.com/how_5114264_use-variac.html
A variac is not a motor speed control; don't attempt to use it on an AC motor. Most variacs, at the maximum knob setting, will output over 120 volts. Use caution when making adjustments; high voltages can damage equipment. Some older variacs lack a grounded outlet. Use caution when plugging equipment into these.

From: http://www.eng-tips.com/viewthread.cfm?qid=200189&page=48
Sigh... Oh well...

Speed of an AC motor is ALWAYS determined by the supply frequency and the number of poles in the motor winding.

Changing the voltage without changing the frequency reduces the TORQUE of an AC motor by the square of the voltage. So for instance at 60% voltage, the torque is .6 x .6 = 36% of the normal torque. If you have a fixed load, the speed reduces because the motor now has insufficient torque to keep it spinning at full speed. DEPENDING ON THE MOTOR DESIGN, that may or may not work out too well, because MOST AC motors will try to keep running the same speed and pull more current to do it, until the motor burns up.

A variac or rheostat (a.k.a. dimmer) can change the speed on SOME TYPES of motors because they have a type of design that inherently limits the current flow, thus allowing the lower torque output to occur without burning themselves up. These are called Shaded Pole motors and most likely your fan is one of these if it hasn't burned up from your test. Another type is a "Universal Motor" which is really more of a DC motor to which you supply AC. This is what you find in small appliances and portable tools, not likely on a fan.

A VFD changes the voltage AND frequency together at a predetermined ratio, which allows the motor to maintain a constant torque while varying the speed by keeping the ratio the same as it was at full speed and full voltage. But it does so by converting the AC to DC, then using high speed transistors to fire DC pulses in what is called a PWM pattern to the motor to recreate a "pseudo sine wave" that the motor reacts to AS IF it were AC. This works great on 3 phase motors. The problem with most types of single phase motors is that the pulsed DC is incompatible with the design of the motors, and you can damage the motor, the VFD or both. Usually both.


From: http://isefaq.com/ActiveKB/questions.php?questionid=2
Can I vary the speed of my motor with a variable transformer?

Many motors can use a variable transformer for speed control.

Motors that usually can be controlled by varying the motor voltage:
Universal Motors
Series Wound Motors
Torque Motors
Shaded Pole Motors

Motors that sometimes cannot be varied by changing the motor voltage:
Split Phase Motors
Permanent Split Capacitor Motors (Imnotcrazy's added NOTE: 99% of inline fans are of the Permanent Split Capacitor type)
Repulsion Induction Motors
Motors with centrifugal switches

Motors with fan cooling can sometimes be damaged due to the decreased cooling effect at lower speeds (depending on load).

Lots of great info imnotcrazy. Last night my max fan 8" burnt out and stopped and by the time I woke up to the smell my room was cooking at 99 degrees. I had it hooked up to a grozone temp 2v and idling at a low speed (supposedly until 85 ambient was reached at which point it was supposed to come on full and cool the room). In the middle of the night I rigged another fan to cool things and was planning to take the max fan in to the shop today. Before I left I checked it one more time and it came on full blast no problem and seems to be working fine now.
I see on the label it says thermally protected". This I assume means- "shuts off when it gets too hot". I can't find any info online about the exact high limit temp on the fan and their offices are closed today (sat). I'm wondering if the grozone controller idling the fan at a low speed coupled with the grow lights warming the air could have led to a hi temp shut down of the fan? I think the groz-one controller is a triac type- which you've said is compatible I think? Any insight would be much appreciated.

 

[reckon]

I run a value line 6" fan (vortex copy), and a harbor freight router speed control

no hum, it starts either full or reduced, nothing gets hot, no problems whatsoever

fan=$110 router control= $20,.....no "jet engine" noise outside the apt, and it's a nice 78 degrees in the garden, RH=45%

easy peasy, bubblebag squeezy