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speed controlling a vortex?
- Thread starter MrMortakis$moot
- Start date
Silver Oak
Member
I called the folks at S&P and asked them about the best way to control the speed on my S&P 100 inline fan.
The technician told me that a Variac is the only way to go. He said they use Variacs when doing long-term testing of their fans. He said the Variac's way of controlling fan speed is the easiest on the fan, much better for the fan than Triacs.
Just letting you know what the S&P factory technician told me...
The technician told me that a Variac is the only way to go. He said they use Variacs when doing long-term testing of their fans. He said the Variac's way of controlling fan speed is the easiest on the fan, much better for the fan than Triacs.
Just letting you know what the S&P factory technician told me...
Outportgrower
Member
Do any of the big box stores carry these so you can walk in and pick these up at, or are you really needing to order on-line or through you local shop?
I am thinking that a HVAC dealer would have these as well, but have not made the call just yet.
I am thinking that a HVAC dealer would have these as well, but have not made the call just yet.
STILL YOU ARE WRONG!!!!!!!!!!!!!!!!!!!!!
STILL YOU ARE WRONG!!!!!!!!!!!!!!!!!!!!!
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).
STILL YOU ARE WRONG!!!!!!!!!!!!!!!!!!!!!
Well notice here the sharp and abrupt "starts and stops" a triac controller creates in order to reduce the magnitude.
That's not good for the motor. It's like turning a light bulb on and off really fast; eventually, that bulb will burn out.
FALSE: A motor is a COMPLETELY different type of load from a light-bulb which is basically a RESISTOR. Light is made from the heat made by providing current to a highly resistive load....
On the other hand, a Variac just alters amplitude:
Honestly, I rather spend $20-$30 extra for a Variac now, than spend $100-$200 for a new fan later (and possibly, bear a greater cost because of its failure).
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).
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P.S.
P.S.
It ALMOST fried your ass because you overloaded the UN-FUSED Secondary Winding. By dropping the Output Voltage to a point that the Output Current burnt the Variac Winding Insulation.
This caused a Short to Ground which I told you was the reason for your GFCI circuit to trip out.
Pontiac, Kudos for all of the info you compile and share but in this case you are spreading bad info....
P.S.
It ALMOST fried your ass because you overloaded the UN-FUSED Secondary Winding. By dropping the Output Voltage to a point that the Output Current burnt the Variac Winding Insulation.
This caused a Short to Ground which I told you was the reason for your GFCI circuit to trip out.
Pontiac, Kudos for all of the info you compile and share but in this case you are spreading bad info....
A little more info
A little more info
The number of windings has little/nothing to do with motor RPM. It is the FREQUENCY of the Input Voltage AND the number of motor poles that determines a Motor's RPM.
A little more info
The number of windings has little/nothing to do with motor RPM. It is the FREQUENCY of the Input Voltage AND the number of motor poles that determines a Motor's RPM.
Silver Oak
Member
The Soler & Palau TD-Mixvent models 100, 100x, and 125 are "Single phase, 120v 60Hz, shaded pole induction asynchronouis motors." It says so in the product spec sheet.
My model 100 has been running fine for months at about 60 volts from my Variac. I highly recommend the TD-Mixvent Model 100, because this thing can move plenty of air, it's very small, and it's very quiet.
My model 100 has been running fine for months at about 60 volts from my Variac. I highly recommend the TD-Mixvent Model 100, because this thing can move plenty of air, it's very small, and it's very quiet.
Ok, now I know the S&P fans are of a current limiting type (Shaded Pole), but to add:
Those type of fans WILL NOT move the equivalent amount of air as a Centrifugal type fan. That's one of the reasons I've been stating that a Variac won't work, because you've gone and chose the wrong type of fan to be used when ducting and high static pressure are involved. Yes, those type of motors are variac speed controllable but they are also far less efficient when compared to centrifugal type inline blowers.
"For a start, recall that the sequence: Axial-Flow, Mixed Flow, Centrifugal (AF, BC, BI, RT, RB, FC), Turbo Blower and Multi-Stage indicates the general trend of an increasing
pressure-volume ratio (SP/cfm) or of a decreasing volume -pressure ratio (cfm/SP).
Furthermore, according to the fan laws, an increase in speed boosts the static pressure more than the air volume, whereas an increase in wheel diameter D boosts the air volume more than the static pressure. Thus, for pressure fans, we will FAVOR CENTRIFUGAL FANS and high speeds combined with small size. For volume fans, we will favor axial-flow fans and low speeds combined with large size. This does not mean that axial-flow fans can never be used in high-pressure applications. It does mean that they will require a higher tip speed than centrifugal fans in order to PRODUCE THE SAME STATIC PRESSURE."
From: http://books.google.com/books?id=Xs_MMEBXaF0C&pg=PT211&lpg=PT211&dq=%22Mixed+Flow%22+Vs.+Centrifugal+Fans&source=bl&ots=crovm_pY9z&sig=AK0S7ucoY_Ynhhu_8HnRT51Ibo0&hl=en&ei=WBN0SuCpBd7ktgfuv9mWCQ&sa=X&oi=book_result&ct=result&resnum=5#v=onepage&q=&f=false
Those type of fans WILL NOT move the equivalent amount of air as a Centrifugal type fan. That's one of the reasons I've been stating that a Variac won't work, because you've gone and chose the wrong type of fan to be used when ducting and high static pressure are involved. Yes, those type of motors are variac speed controllable but they are also far less efficient when compared to centrifugal type inline blowers.
"For a start, recall that the sequence: Axial-Flow, Mixed Flow, Centrifugal (AF, BC, BI, RT, RB, FC), Turbo Blower and Multi-Stage indicates the general trend of an increasing
pressure-volume ratio (SP/cfm) or of a decreasing volume -pressure ratio (cfm/SP).
Furthermore, according to the fan laws, an increase in speed boosts the static pressure more than the air volume, whereas an increase in wheel diameter D boosts the air volume more than the static pressure. Thus, for pressure fans, we will FAVOR CENTRIFUGAL FANS and high speeds combined with small size. For volume fans, we will favor axial-flow fans and low speeds combined with large size. This does not mean that axial-flow fans can never be used in high-pressure applications. It does mean that they will require a higher tip speed than centrifugal fans in order to PRODUCE THE SAME STATIC PRESSURE."
From: http://books.google.com/books?id=Xs_MMEBXaF0C&pg=PT211&lpg=PT211&dq=%22Mixed+Flow%22+Vs.+Centrifugal+Fans&source=bl&ots=crovm_pY9z&sig=AK0S7ucoY_Ynhhu_8HnRT51Ibo0&hl=en&ei=WBN0SuCpBd7ktgfuv9mWCQ&sa=X&oi=book_result&ct=result&resnum=5#v=onepage&q=&f=false
Outportgrower
Member
The Speedster is a great multi-purpose speed control. Three settings include off, on (full) and variable. Simply use the dial to increase or decrease fan motor speed. 120 volt/15 amps.
NOTE: For use with brush-type motors only (i.e. Vortex, Fantech, Elicent, etc.). Not for use with blowers (i.e. Dayton, Active Air, etc.).
So, once again would these be able to be picked up at your local big box store, or local HVAC dealer or garden center? Pretty simple question really. My 6" vortex makes far too much noise at full tilt even with the background noise from the dehumidifier running 24/7. Kinda need to drop it down a notch or three.
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.
NOTE: For use with brush-type motors only (i.e. Vortex, Fantech, Elicent, etc.). Not for use with blowers (i.e. Dayton, Active Air, etc.).
So, once again would these be able to be picked up at your local big box store, or local HVAC dealer or garden center? Pretty simple question really. My 6" vortex makes far too much noise at full tilt even with the background noise from the dehumidifier running 24/7. Kinda need to drop it down a notch or three.
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.
I must reiterate: Fantech, Vortex and Elicent fans are Permanent Split Capacitor NOT BRUSH TYPE MOTORS
LMFAO
Outportgrower
Member
So you never really answered the question as to what big box type store or local HVAC type dealer, garden supply outlet would carry such a unit as the Speedster since it is made and sold for use with the fans you mentioned above. You seen to know all about these, and you would think that you might also know where to find them other than on-line.
Grainger Outlets (distributor of Dayton products) Carry the Triac speed controls.... They have warehouses nationwide (US)
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?
Wait I'm conrfuuzed,.....iz them "Brush Style Motors"
Or Not?
Maybe U cud splane it Better?
and Type slooooo soooz I can read it.
Or Not?
Maybe U cud splane it Better?
and Type slooooo soooz I can read it.
Brush-type AKA Universal AKA Rectifier motors, are exactly what the last name describes; there is a Half-Wave rectifier (AC to DC Converter) in series with the motor. What this does is allow you to apply EITHER AC OR DC to the motor. The built-in rectifier allows any DC applied right on through to the motor winding. Any AC applied is half-wave rectified into DC and then to the motor. The DC whether applied direct or rectified AC is then applied to the armature via "brushes" which look like a big chunk of pencil lead.
The electromagnetic field that is created is uni-directional and usually (in fractional horsepower motors) uses a permanent magnet to "push" against. This causes the armature to turn.
You find these type of motors in Power Tools like drills and routers.
Permanent Split Capacitor Motors:
You apply Single Phase AC and the capacitor on the second winding causes a phase shift compared to the primary winding which bypasses the cap. This phase shift creates a rotating magnetic field which causes the rotor/armature to turn.
If you're motor has a capacitor in the wiring box, then it is of the PSC type. Fan motors are USUALLY PSC OR Capacitor-Start type (oscillating fans etc). Capacitor-start type motors ARE NOT speed controllable.
The electromagnetic field that is created is uni-directional and usually (in fractional horsepower motors) uses a permanent magnet to "push" against. This causes the armature to turn.
You find these type of motors in Power Tools like drills and routers.
Permanent Split Capacitor Motors:
You apply Single Phase AC and the capacitor on the second winding causes a phase shift compared to the primary winding which bypasses the cap. This phase shift creates a rotating magnetic field which causes the rotor/armature to turn.
If you're motor has a capacitor in the wiring box, then it is of the PSC type. Fan motors are USUALLY PSC OR Capacitor-Start type (oscillating fans etc). Capacitor-start type motors ARE NOT speed controllable.
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Silver Oak
Member
Imnotcrazy, I'm beginning to think you might me a little crazy.
I never said the S&Ps would move the equivalent amount of air as a centrifugal fan. Why would you argue against something I never said? That's called a Straw Man argument, and its a sign of weakness in your own case.
I've chosen the exact right type of fan. It is small, and it moves way more air than I need for my cabinet, and it runs essentially silent.
Honestly, I've been reading all your posts in this thread and in a few others, and I'm slowly coming around to the position that you're talking out your ass at least half the time.
I was only stating different types of fans for the OBVIOUS REASON:
You were not the only one who asked questions. Honestly that last post regarding motor types was to answer 2 things:
DrBudGreengenes last post
AND
Why I recommended Solid State Triac type Speed Controls in the first place: Axial Type (Shaded Pole Type Motor) Fans Are Practically Useless when compared to the same diameter centrifugal type fan if they are intended to be used under any static pressure IE: Ducting is involved
Also, Clarifying that point allows the others reading the thread to be able to DETERMINE THE PROPER SPEED CONTROL METHOD FOR THEIR FAN
And yes, I'm talking out my ass; That's why I get paid to do this type of shit for a living You Condescending Pratt
You were not the only one who asked questions. Honestly that last post regarding motor types was to answer 2 things:
DrBudGreengenes last post
AND
Why I recommended Solid State Triac type Speed Controls in the first place: Axial Type (Shaded Pole Type Motor) Fans Are Practically Useless when compared to the same diameter centrifugal type fan if they are intended to be used under any static pressure IE: Ducting is involved
Also, Clarifying that point allows the others reading the thread to be able to DETERMINE THE PROPER SPEED CONTROL METHOD FOR THEIR FAN
And yes, I'm talking out my ass; That's why I get paid to do this type of shit for a living You Condescending Pratt
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