View Full Version : Looking for RSU99 replacement

06-01-2005, 07:58 PM
Hi guys.

Came across an old AC package controlled by RSU99 made by Stefa Controlls.
Two cooling stages.
Two heating stages.

It was lat so I didnt call anyone to start searching on this side of the world.

Any idea anyone??


Chemi :)

06-01-2005, 08:36 PM
Hi chemi

Steafa are now under the Seimens umbrella so I did a quick search on their site but unfortunately, the RSU series is not listed. See here http://www.sbt.siemens.com/hvp/staefa/search.asp?SearchString=rsu&ACTION.x=15&ACTION.y=0


06-01-2005, 08:49 PM
Thanks Frank.

I am thinking of installing there a simple temp controller with two stages and a dead zone.

I will look tomorow for something.

Chemi :)

06-01-2005, 09:01 PM
Have a look here Chemi http://frostechnic.com/eliwell.htm

06-01-2005, 09:39 PM
We use for such an application the Polygyr from Staeffa, Siemens now.
But I think I know the cards you mean Chemi: is there not a small red button on the front and on the bottom?
If you push it, the alu cover pushes away from the regulator and behind the cover are the switches and potmeters.
The card snaps in a base wit two long bolts with a spring along the bolts.
In the corner of the card you must turn some sort of marker so that it fits in the base just in the right place.

If it's that, then you can use the Polygyr. You can use it anyway for your application. Cost for a Polygyr around 400 to 450 I think.


06-01-2005, 10:45 PM
Just a thought Chemi, is the control actually dead ? Have a look inside under the side cover and check to see if there are still any spare transistors in their holders; if so it might be worth while changing them to see if the beast will restart.

Other than that please give it a decent burial having died at a ripe old age ;)

07-01-2005, 04:40 AM
Thanks guys.

Frank, its a good site, kept it in favorites.

Peter, the one you show, is a different one, we use it in AHU.

its a cooling and heating with two lamps which show cooling or heating demand and a temp dial.

Going out now and among other things, I will start looking.

Chemi :)