Older Tunze Osmolator 3155

[alienz]

Roger,

I have an older unit with the old school larger power supplies. I'm not sure if that is going or if the control box itself is dying but it started having trouble pushing current to the pump and has slowly seemed to almost completely die.

At first I thought it was a dead pump so I replaced it, but then got a Osmolator mini and the same pumps work like champs.

So basically my question, is there anything I can do to try and revive the old unit? New power supply?

Thanks and thanks for taking care of the tunze section of the forum all these years!

 

[rvitko]

The old power supply was pretty robust, unlike the more modern switching power supplies which basically rapidly oscillate to let just the 12V through of 115V and in doing so convert it to DC, the old ones were a copper coil and a rectifier and I have only ever seen the rectifier fail and very rarely, then you usually see the lights strobe on the controller very rapidly, it is almost imperceptible. My guess is the following, prior to 2008, which yours would be due to the power supply type, the pumps had a single seal between the motor and impeller and the controller cut off the pump if it draws more than 800mA, the pump will slow to a stop in some seconds or minutes as this circuit breaker breaks contact. New pumps have 2 seals and need more power as will an old worn pump. We now use a 1200mA breaker and the pump needs about 1000mA. You can usually get the old ones to work by switching the power supply to 9V, making sure all connections and wiring are clean and free of corrosion and possibly increasing the head pressure (the pump uses less power with more head pressure). Make sure the connector for the pump is rust free, it is a European terminal connector available at Radio Shack, cut back the black wire from controller until you get shiny copper, it will likely have wicked in some saltwater over the years and be oxidized black for some inches. All of these steps should get us below the 800mA limit so it works.

 

[alienz]

I didn't mention it but the lights on the unit did strobe, but at a rate that you could see. And it got worse over time. So perhaps the power supply in fact did fail.

I did give it a new terminal connector and chopped back the wires. But thanks for the info.

Can't be too sad, it served quite a long time. Is it possible to order just power supplies or is it not going to work with the older unit?

 

[rvitko]

The current power supply is 12V only and would cause the problem I described. You could get a 9V power supply at Radio Shack, it would need to be 800mA