Decent inline fan controller?

[ak-51]

will this one run my 12" max fan??
the site has others that are bigger?
how do you size a variac for a 12" maxfan??

Well that one I listed is rated at 5 amps. I think your Max-Fan is like 4.1 amps, so it should be able to run it.

I remember something about not wanting to run something at 80% of it's max capacity for long periods of time. That was referring to the circuit breakers, but I think the same would probably be true for many electronics. 4.1 amps is only 82%; I don't think that's too egregious. I think it would be worth a shot. The worst that will happen is it might blow the fuse. I'm pretty sure mine came with a spare fuse.

Best to post in Growroom Electricity and Wiring if there's any question about it. I think I know more than the average person about wiring, but I'm nowhere near being as experienced as some other people on here. Some people that post in that thread are actual electricians.

if you run it less than 50% it will overheat, it can't cool its self.
nothing to do with the variac.
get a smaller fan if you have to run it 50% or less

Won't the heat produced by the motor decrease proportionally with the speed of the motor?

I have been running my 10" Sunleaves between 50 and 60 volts for almost a year, 12 hours a day. I'm not saying that proves that there's no harm done to it, but it hasn't melted down yet. It's certainly possible that my doing that has been putting excessive wear on it the whole time. It does still seem to be functioning properly though.

 

[RM - aquagrower]

Input: 120 volt AC, Output: 0~130 volt AC, 5 amp slow blow fuse
VA: 500VA, 5 Amp. Max (surge), 1 year warranty
A rating of 500VA means that at 100volt, the unit can sustain at maximum 5amp. If at 120 volt the unit can sustain at 4.1amp
Note that most device have surge (when first turn on) much higher than operating amp rating.
E.g, motor with 5 amp rating may have over 10 amp surge, and you will need 10 amp variac

^^^Taken from this link http://www.amazon.com/Variac-Variab...ie=UTF8&qid=1362781785&sr=8-4&keywords=variac

With that in mind, if my fan was pulling 4.1 amps, I would step up to the 10 amp unit. When I ordered the 5 amp model, I did it knowing that I probably can't run my 12" fan with it, and would have steped up to the 10 amp if I had more cash.


Just food for thought.

 

[the gnome]

thanks for the input RM/AK

i think the 10 amp one sounds like a good idea,

AK, on the heat issue this is what canfan said on their website
here's the disclaimer you get looking at maxfans,
it not on the canfans, only maxfans so it may be applicable to only certain types of fans.

*This is the required control to use with your 12" Max-Fan.

** Fans should not be reduced more than 50%, this allows for airflow to cool the motor**


ok,, looking more the variac is only needed on the 12" max fan, and not other sizes of max's?

what luck lol.

then it says this
10" and 14" Max-Fan are speed controllable 8" and 12" Max-Fan are speed controllable

 

[RM - aquagrower]

I have 2 of the hydrofarm versions of these http://www.plantlightinghydroponics.com/active-air-variable-speed-fan-control-p-2263.html and can tell you that I won't use them to slow down my vortex fans.

Causes a loud humming that heats up the fan moters. Can't be good for them, and them fans weren't cheap.

 

[ak-51]

Well it definitely won't be a bad thing to have a higher powered variac. The only thing negative would be the upfront cost, which I think is negligible when you consider how heavy duty these things are (well at least they seem that way).

My setup may be different from a lab or hypothetical situation where a fan motor is run below 50%. See the way I am arranged I have 2 tents side by side. Both of these tents have their own scrubbers and 6" in-lines pushing through the hood then venting outside the tent. My 10" is pulling air from outside the tents, through a 10" to 8"x2 Y duct and then one 8" duct blowing fresh air into each tent. Even if I were to shut off the 10" fan, there is still a good amount of air being sucked through it just by the fact that there is negative pressure in each tent.

So long story short my 10" has air movement through it beyond what it itself is producing.

Before I got the variacs that I have I had rigged up my own speed controller. I think I read/was told somewhere that you could use a dimmer switch as an in-line fan speed controller*. This caused a loud humming and I unplugged it immediately and never used it again.

*Believe it or not, now that I'm thinking about it, I think it was the hydro-shop owner that told me this.

 

[rives]

A dimmer (rheostat) should never be used with an AC motor. They insert resistance into the line, which works fine to dim an incandescent light bulb but doesn't work with a motor at all and is potentially destructive to both components.

The best way to do speed control of a motor is with a frequency drive. Unfortunately, there appears to still only be one manufacturer for single-phase fractional horsepower motors, and they are very expensive and difficult to source.

The triac-based speed controllers work by switching on & off very quickly, so that the motor is fed power for segments of the wave form rather than the whole thing. This is what makes the characteristic humming sound from motors controlled this way. They are probably the cheapest and most effective method of fan speed control, but some motors simply do not work with them.

Variac's are variable transformers, which change the voltage output rather than the frequency. This works, but is not recommended for motor control because as the voltage drops, the amperage rises proportionately. Inline fans can get away with their use better than most motors because they are cooled by the air flow going over them, but the amount that you can turn them down is limited. They create the worst situation for motor longevity - increased heat from the current going up, combined with restricted cooling. Variacs are the only choice for some motors, which is why CanFan stipulates them for certain models.

 

[ak-51]

as the voltage drops, the amperage rises proportionately.

So the wattage stays the same? And does this mean that if I turn it down low enough that the amps will rise high enough to blow my fuse?

I have never been 100% clear on exactly how variacs work and it is starting to bother me.

 

[the gnome]

once again, thanks for dropping in senor rives
and making sense of things I can't make sense of

 

[intotheunknown]

RIVES hey dude...^^Im also using the router speed controller found at harbor freight... working well, havent had any issues for the multiple years ive been using them.
20 bucks a pop.

whats your opinion on these?

 

[rives]

So the wattage stays the same? And does this mean that if I turn it down low enough that the amps will rise high enough to blow my fuse?

I have never been 100% clear on exactly how variacs work and it is starting to bother me.

AK, yes, motors try to keep the same horsepower output across voltage changes, so the current fluctuates accordingly. Our friends across the pond don't rate motors in hp - they go by kw.

A variac is simply a transformer that, instead of taps, has a portion of the windings exposed for the adjustment brush to travel on. This gives an infinite range of adjustment rather than the few discrete steps that transformer taps will usually give.

RIVES hey dude...^^Im also using the router speed controller found at harbor freight... working well, havent had any issues for the multiple years ive been using them.
20 bucks a pop.

whats your opinion on these?

That is one example of the triac-based controller that I was talking about above. You will also find them labeled with the "Speedster" name. If your fan works with them, great. Some do not, and some take some re-arranging of the capacitors to work with them. Once again, though, you shouldn't try to slow the motor down too much with them. You may slow them down to the point that they will run fine until you get a power interruption (intentional or not), and then not have enough starting torque to get spinning again. The motor will then burn up because it cannot cool itself.

 

[rigrig]

I'm using a CAP VSC controller. Amazon has it for around $70. It is a 15 amp temp controller and a fan speed control in one. It works similarly to the ones described above, by pulsing the power on and off. It has reduced the noise in my grow room greatly by only running at low speed most of the time.

I had a problem with my first controller from CAP when it was well over a year old. CAP paid for shipping both ways, and replaced it in about a week.

I highly recommend it unless you have a really expensive fan, in that case I'd buy a controller that is made for greenhouses($$$).

 

[MsMileHigh]

AK, yes, motors try to keep the same horsepower output across voltage changes, so the current fluctuates accordingly. Our friends across the pond don't rate motors in hp - they go by kw.

A variac is simply a transformer that, instead of taps, has a portion of the windings exposed for the adjustment brush to travel on. This gives an infinite range of adjustment rather than the few discrete steps that transformer taps will usually give.



That is one example of the triac-based controller that I was talking about above. You will also find them labeled with the "Speedster" name. If your fan works with them, great. Some do not, and some take some re-arranging of the capacitors to work with them. Once again, though, you shouldn't try to slow the motor down too much with them. You may slow them down to the point that they will run fine until you get a power interruption (intentional or not), and then not have enough starting torque to get spinning again. The motor will then burn up because it cannot cool itself.

What are some quality fans work with the triac"speedster" speed controllers?

 

[VerdantGreen]

in europe you can get a temperature controlled inline fan that has 4 speeds and 4 separate wirings.

 

[rives]

What are some quality fans work with the triac"speedster" speed controllers?

The only fans that I have used with the triac-based controllers are the Fantechs. They get a little noisier, but have been running for several years with no problem. I recently bought one of the new Fantech "EC" series fans, which have an integral electronic control and are supposedly controllable over a much wider speed range. Unfortunately, I don't have it installed yet.

 

[WillyNilly]

The only fans that I have used with the triac-based controllers are the Fantechs. They get a little noisier, but have been running for several years with no problem. I recently bought one of the new Fantech "EC" series fans, which have an integral electronic control and are supposedly controllable over a much wider speed range. Unfortunately, I don't have it installed yet.

Hey Rives, I'd be curious to know how that Fantech "EC" works out for you once you install it. Do they come with a controller? If not, what type of controller are you planning on using with it?

 

[rives]

Hey Rives, I'd be curious to know how that Fantech "EC" works out for you once you install it. Do they come with a controller? If not, what type of controller are you planning on using with it?

The fan motor is apparently a completely different design than a standard motor, and all of the controls are built into the fan with the exception of a potentiometer or 0-10vdc source. It's been a while since I looked in the box, but I think that they included the loose pot for installation. I am planning on using it with a PID-loop temperature controller so that the speed will automatically adjust to hold a given temperature setting. It is a damn nice looking fan, metal housing, and the EC series seems to handle static pressure better than their standard line.


http://www.google.com/url?sa=t&rct=...mpiKUAplJehMH0I6iF0B9Ww&bvm=bv.44158598,d.cGE

 

[Greenheart]

RIVES hey dude...^^Im also using the router speed controller found at harbor freight... working well, havent had any issues for the multiple years ive been using them.
20 bucks a pop.

whats your opinion on these?

View Image

The one above did not work on my 10" vortex. I contacted the company they explained it needed if i remember right a "solid state" controller. When I pressed for a specific name she told me they didn't want to refer any specific brand but a "dial-a-temp" would work. I tooked the old one back and got one of these in the link below like BudToker and the company suggested. No more "buzzing" or "clicking" sounds. In the end I didn't think it really quieted things significantly enough so it sits on a shelf.

This is what you want:

Dial A Temp

View Image

They usually cost about $30 but you can get it here for ~$15:
http://www.amazon.com/Lectro-Kennel-Heat-Rheostat-Temp-Control/dp/B0002IEQNW

Good Luck,

- BT