Seios can't be run off a controller??

[edsreef]

I've heard this many times; that Seio recommends against running their pumps off a controller/timer. I read the manual that came w/my 1500's and checked on the box and I couldn't find that anywhere. I've done searches and only found people telling each other they "thought" or "heard" that Seio recommended against this.
So, my question is, where does this info come from???????
Just the facts, please!

[MarkM3]

The idea is that most rio's do not use ceramic cartrige bearings (I'm not sure on the seio, but I assume they dont either.) They will run fine on a wavemaker for a while (people have done it) but over time the hole (spindle) in the center of the impeller magnet will wear slightly. As the hole wears over a few months, the pump will chatter on startup, eventually finding it's center as centrifical force kicks in. Thus, the reason they are not recomended as continuous on-off cycles is over time they will begin to chatter/grind on startup.

[edsreef]

Seios have ceramic bearings and shafts and already chatter a bit on startup.

[bement14]

Will it break the pump itself, or just the impeller?

[Stevan]

I thought they were coming out w/a manuf. built controller.

[edsreef]

Seios can't be run off a controller??

I've heard this many times; that Seio recommends against running their pumps off a controller/timer. I read the manual that came w/my 1500's and checked on the box and I couldn't find that anywhere. I've done searches and only found people telling each other they "thought" or "heard" that Seio recommended against this.
So, my question is, where does this info come from???????
Just the facts, please!

[edsreef]

Stevan:
I've heard they are too. It must be a majic controller - only it can run them properly!

I'd really like to figure this one out - why does everyone say they can't or shouldn't be run off a controller?

[jdg]

I know I read it somewhere ... I think it was on an Online Retailer's site ... I'll try to find the link and post ...

[edsreef]

jdg: thanks.

I found this on Marine Depot's website:

Note: Seio pumps are not recommended to run on a wavemaker device.

I've e-mailed them asking them where they got this info, why not to put them on a wavemaker, and by "wavemaker" do they mean an electrical/electronic device or a plumbing device that creates backpressure and "pulses" of water?

[jdg]

Cool! Glad you found it ...

Let us know what they come back with please ...

[manderx]

you shouldn't run them from an off-the-shelf controller because startup on a seio is kinda rough. since it's AC, there's a 50/50 chance it will start turning the impeller the wrong way (pulling water vs pushing water), and it has to chatter a bit to get going the right way. no big deal if you only turn it on/off occasionally, but every 15 seconds would wear out the catch-mechanism.

[edsreef]

manderx:
Thanks for the response. Could you elaborate on a couple of things though:

since it's AC, there's a 50/50 chance it will start turning the impeller the wrong way

How could this happen? It's got a polarized plug (and a ground so that it can only be plugged-in one way) and as far as I know the coil and rotor will only spin or "pull" the impeller in one direction; it's made to do this. I've heard people say this too about MJ's, but in my own personal experience, using them (MJ's) on a wavemaster for years, I've never seen this happen. It would have been nice though, and clean my intake screens occaisonally - but it never happened.

but every 15 seconds would wear out the catch-mechanism

What "catch mechanism"? Don't think mine has one of these.

Not trying to be anal here - just trying to get this figured out. I've always kind of tried to think "outside the box".

[manderx]

How could this happen? It's got a polarized plug (and a ground so that it can only be plugged-in one way) and as far as I know

a polarized plug is to differentiate between hot and neutral. AC (alternating current) moves both ways, switching 60 times a second.

the coil and rotor will only spin or "pull" the impeller in one direction; it's made to do this. I've heard people say this too about MJ's, but in my own personal experience, using them (MJ's) on a wavemaster for years, I've never seen this happen. It would have been nice though, and clean my intake screens occaisonally -

when the powerhead gets power, an electromagnet is energized which then interacts with a permanent magnet in the impeller. which pole is North/South depends on what direction the current is flowing for that 1/60th of a second. it will either push the magnet in the impeller or pull it. 1/60th of a second later, the polarity of the electromagnet changes, and the magnets in the impeller are designed to be in the right place at the right time for the new field to keep spinning it in the current direction rather than acting aganst the momentum of the impeller. this is why pumps designed for europe's 50hz don't work here. 110v vs 220v is a trivial conversion compared to converting 50hz to 60hz.

on a centrifugal powerhead, it doesn't matter what direction the impeller spins since the blades are straight. as it spins, in either direction, water from the center gets flung out in all directions. this causes high pressure around the impeller blades and low pressure at the hub. the water inlet is near the hub, so water 'sucks' in. pressurized water flows around the tips of the spinning blades and out the nozzle. reversing the direction would not make water go out the inlet strainer. but it does change the direction water flows inside the impeller housing, clockwise or counterclockwise as it's squeezing around the impeller to get out. a neat maxijet/wavemaker mod that exploits this is to saw-off the nozzle. without a nozzle, the water comes out at an angle based on what direction the impeller is spinning. as you turn it on and off, you clearly see water coming out alternating randomly between 2 different directions. do a search on 'maxijet mod nozzle' and i'm sure you'll find several threads on this. one even has a video showing this in action.


since the seio has curved blades, if you reverse the spin on it, it will send water out the inlet strainer. you don't want this, so they had to put some sort of mechanism in there to catch it and reverse it's direction.

[bement14]

I heard the "softstart" on the reefkeeper from digital aquatics runs them better than a regular wave maker.

[jdg]

Originally posted by bement14
I heard the "softstart" on the reefkeeper from digital aquatics runs them better than a regular wave maker.

I heard the same thing; though, unfortunately, the only place I've seen it is in their own marketing materials

[edsreef]

manderx:
Thanks. That makes sense.

[TrojanScott]

As someone who's going to run a couple powerheads in his new tank, I just wanted to say I think the SEIO's are pretty cool!

Didn't know about the timers though, thanks for the thread.

[edsreef]

OK. Here's what I've come up with. Thanks to Marine Depot and Taam for thier quick responses:

First my question and answer from Marine Depot:

Hello, You say the following in your description of the Seio powerheads: "Note: Seio pumps are not recommended to run on a wavemaker device." I'm wondering where does this info come from, why not, and does this mean an electrical/electronic device that turns them on-and-off, or a plumbing device that create "pulse" waves?

Thank you for your inquiry, When we say wave maker we are talking about a electronic device that turns the pump on and off. The reason that they don’t recommend use with one is that it is hard on the pumps, the magnet the impeller incur more stress if used with such a device. If you have any further questions please contact us.

Next, my question and answer from Taam, Inc.

I've heard that these pumps are not recommended to be used with a wavemaking device because it can cause stress to the impeller and magnet. Is this true? I also hear you are coming out with a controller designed for use with these pumps in the near future. Is this true? Is so, I may be interested in purchasing one or more but would like to know how your controller can reduce or eliminate these stresses to the impeller and magnet?

Yes, we do not recommend to use these pump on a on/off timer. If you do, you will accelerate the demagnetization to the magnet rotor and there is a chance of breaking the shaft. The bottom line is you end up replacing impeller rotor sooner than you wanted to. Yes we have been testing our controller. As soon as we are comfortable with the unit , we will release the controller to the retail market.

Although they didn't address the question about how their controller will reduce or eliminate the stresses on the impeller and magnet, I assume it will have to be some sort of "soft start" feature. I'm glad to have some answers and to know this wasn't just some sort of marketing propaganda, but I'm still a little skeptical as to whether-or-not the Seios would work on another controller equally as well as Seio controller - something we'll have to find out in time I guess. Hopefully this thread will help others who've wondered as I have about this. Feel free to add your comments or opinions on the topic here, espescially if you've used the Seios on a timer or wavemaker.

[ich_meistr]

Not to bash anyone but I was very skeptical of Mandrex's response. Especially about the part about AC switching and magnet being in the correct place. I said to myself that this would mean that the person plugging in the unit would have to know the phase of the current and only plug the unit in when it was on the + phase so that impeller would turn in the correct direction.

Glad to see that it's just an issue with the impeller. I've had similar issues with the Hagen AquaClear 802 powerheads being run off of the Red Sea Wavemaker. The impellers were loosely connected to the magnetic shaft and would wear out with time due to the on/off cycle.

Thanks edsreef for this clarification !!

Now I guess I just have to find out how much the replacement impellers cost to see whether I can live with the cost of running these off of a wave maker

[edsreef]

Yeh, I'm still a little fuzzy on that one. What makes the impeller turn in the correct direction when you plug in the unit that wouldn't also make the impeller turn in the right direction when started by a controller?

manderx:
You seem to use good logic for your reasoning; could you help to clarify this?

they had to put some sort of mechanism in there to catch it and reverse it's direction

Is this the elusive mechanism you speak of? Has anyone seen it or know how stoutly it's built?

[edsreef]

OK, I've posed another question to Taam. Don't know what kind of response I'll get; I actually expect some sidestepping, but I asked if another controller with a "soft start" feature would be suitable to use with them. I have a Redsea Wavemaster that's supposed to have this feature, correct me if I'm wrong.

If you noticed, they said:

we do not recommend to use these pump on a on/off timer

To me, an on/off timer and a controller with a soft start feature are two different animals.

[manderx]

Not to bash anyone but I was very skeptical of Mandrex's response. Especially about the part about AC switching and magnet being in the correct place. I said to myself that this would mean that the person plugging in the unit would have to know the phase of the current and only plug the unit in when it was on the + phase so that impeller would turn in the correct direction.

for a standard centrifugal powerhead with straight vanes, the phase during the instant you plug the pump in does not matter at all. the impeller will spin in either direction and it will pump water all the same. the chatter you hear when you plug it in is the impeller coming up to speed and getting in sync with the alternating magnetic fields, regardless of which way it's spinning.

more complicated pumps vary the shape of the vanes on the impeller to make it more efficient and or boost it's pressure rating at the cost of being directional. i just saw the inside of a rio hyperflow a few weeks ago. it's impeller is a disk with directional vanes/slots cut in it. for it to work, it has to be spinning in the correct direction, otherwise it would work at a fraction of it's efficiency if not outright try to pump water a little bit backwards. i didn't study their design too carefully, but it looked like there was a flap that closes off the output when it's spinning in the wrong direction. this probably causes the impeller to studder some, and during these convulsions eventually start up in the right direction and open that flap.

i have heard of some directional pumps that use a mechanical arm that physically swings out and grabs the impeller when it's going the wrong direction. i believe the AC version of the stream does this, but i've never seen one and am just going from memory from a post i read a while back. the DC version of the stream does not have to worry about this and is highly controllable since DC is traveling in one direction only, and they can simply adjust the voltage to adjust the RPMs.

i have no idea how the seio does it exactly, but there *has* to be some deliberate mechanism designed into it to stop the impeller if it's going in the wrong direction and then reverse it. that's the chatter you hear when you start it up.


this extra effort that directional impellers go through to get started is exactly why they tell you not to run these pumps on a wavemaker that turns things on and off. 'softstart' has to do the same thing, but it's probably kinda like double-clutching and does so a bit weaker at first so it's a little less violent, but it's still not good for a pump to have to go through that every few minutes. i've actually never heard of anyone mentioning 'softstart' making any noticable difference. the new controller from seio probably does not allow the impeller to come to a complete stop. everyone is very curious as to how they did it, whether they adjust the voltage, frequency or what....


read this thread:
http://archive.reefcentral.com/forum...5&pagenumber=1

[edsreef]

Got a response back from Taam, Inc.
Here's my question and thier answer:

Thanks for your quick response. I understand the need for "industry secrets" so you don't have to tell me "how" you do it, but can you tell me that your controller will reduce the need for "replacing impeller rotor sooner than you wanted to?" And would another controller with a "soft start" feature be suitable to use?

The cause of demagnetization is from the starting torque of the stator. Each time the motor start more magnetic field will have to generate from the stator in order to turn the motor, thus a little of the magnetic field is being remove. After so many times the motor is on/off eventually the permanent magnet will lost its energy property and no longer be able to turn the impeller, so the motor stop working. Other disadvantages associating with on/off timer is the starting torque in each time the motor turn, the impact between the plastic rotor and the magnet it will weaken the plastic impeller in time it will crack or it may snap the ceramic shaft. That is why a special controller is require in order to work with the 115v two phase AC motor and we are working on one, unlike the low voltage motor where controlling design is much easier. Thank you for taking interest on Rio products.

Now I'm really starting to wonder about their new controller. Maybe they are going from AC to DC back to AC again; or from AC to a modified DC signal in them like I suggested in another thread (kind of like a VFD)?

[aquaman222]

Buy a maxijet. Problem solved. Taam makes crappy pumps period. I've never owned one that worked for more than 4 months.

[edsreef]

Please tell me you're kidding - I've got a 5gal bucket full of MJ's the two Seios replaced! In case you haven't heard, the Seios are not the old Rio style pumps. I can vouch for the long term reliability of the MJ's but can't yet for the Seios so go ahead and get your shots in now while you can. I can't say whether the Seios will work out in the long run or not but at least I have the kahunas to try.

On another note:
BINGO!! I just got an e-mail from someone who MAY have inside information on the Seio controller. What he suggested (and he made it sound like speculation) was that the controllers will "most likely slow the pump down rather than shut it off completely!" This, I feel, is the answer! I'm not naming names so please don't ask - I don't want to quote someone on speculation and have it be made out to be the facts.