Profilux, Tunze Stream 6100 and split magnets.

[DNA]

I have 4 Tunze stream 6100 that all have split magnets on the rotor and only one of them is still running.
These have all been running for 10 years constantly so there are no complaints on the durability, but all of these magnets split in the last few months.

Some state that the control voltage for the pumps should not exceed 8V, but I disregarded that and set them to 100%, because it is not logical from a design point of view and it reduces the needed flow as well. Do you think this could be the case or is it just a strange coincident.

(The rotors are not available from Tunze at the moment).

 

[rvitko]

10 years out a drive unit is extremely long, in general the drive units should be replaced after about 4 years, even if they still work they do lose some of the magnetic power. I think it is just coincidence/age but I also would not recommend excedeing the 8V limit.

 

[DNA]

Thanks for your reply.

Talking about coincidence, 10 minutes after I read your reply the last pump stopped so now I have 4 unusable Tunze 6100 stream pumps and my tank is left with only one 6205 which is far from being enough and I need to solve this really fast.

Around here reefers have very limited resources and there are no decent stream pumps available and no drive units either. I tried to order drive units directly from Tunze 10 days ago, but they cancelled because I ordered from the U.S. and said none were available until April.

I can't wait that long and the 6100 pumps are very good so I'd like to use them for a few more years.
Are these drive units something most decent Tunze dealers would have in stock?

Got any good ideas?

 

[rvitko]

What drive unit do you have now? You probably have 6080.600 and in this case you should be able to buy the old magnet only 3000.650 and repair the drive units. The drive units have been hard to get for about 1 year. The molds were old and worn and up until late last year they had to be hand polished and trimmed to remove any defects and blemishes. They are making new molds for all old drive units and that is why the delay. You may be able to find them, but in the US they have been in short supply, we have none.

 

[DNA]

Oh thanks, that was a really good advice.
I'm on it already.

 

[DNA]

Finally I got the magnets today and have spent several hours on this.

The new drive units do not get 3 out of the 4 pumps going again.
They start spinning and stop within a couple of turns, most often not making even a single one.
I'm good at fault finding and have isolated the problem with the pump units that have no moving parts.
The power supplies, drivers and drive units all work fine with the one pump that's working.

It's like the magnetic field is not strong enough or out of phase.
Magnets can fade with age but the new ones are no stronger than the old ones.
That leaves the one in the pump, but I have no reference for comparison.

Since I'm in a dead end I'm asking for your advice please.

 

[rvitko]

Either the motor or driver is dead. Given the age, this is not very unusual. If you have a watt meter, you can get a better idea, a wattage of 400 about will generally indicate a dead driver, the driver will also get very hot, a low wattage (below 40 at full power or one below about 200 but above 60 will generally indicate a bad motor), the driver should alarm as well. These parts aren't available new anymore, you may see if you can find them used.

 

[DNA]

The results are in.
The Tunze 6100 pumps are unlikely to last much more than 10 years of continues use.

Guess what, I'm definitely going for new Tunze pumps.

 

[kttran_2005]

What are you going to do with the magnet? Are you plan to sell them? I need one for my DIY wave box. My small magnet is not strong enough to hold the box. Anyway, let me know if plan to sell some.
Thanks

 

[DNA]

I'll use them in some future project.
I was using these $25 third party magnets since none came with the pumps.