Wirsbo 212 control question

Wayco Wayne

My question has to do with the 10K indoor sensor option. If installed how far can it shift the re-set curve to adapt to temperature deviations? Also what settings would you recommend for a re-set on a radiant baseboard loop running off the control? Thanks for any input. WW

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Tim Doran

Call Me

Hi Wayne,
Give me a call on Monday so that we can discuss the particulars. 952-997-5334 If you need to get it going sooner you can try my cell phone. 612-865-6059

Tim D.

hydronicsmike

Man!

This is what I call excellent Customer Service!

Paul Rohrs

No Doubt

However, I would like to hear the suggestions.

I use the promix 212 alot. VSIM is just something I really endorse. It's kind of like Carol Feys breakdown of "power, switch, and load". I can always tell whats wrong with an injection pump, outdoor reset system because the parameters are so well defined.

I have not used the optional indoor sensor for my jobs. I thought it would be a redundancy the homeowner didn't need.
I always zone by circulator with a multiple pump relay. I use the endswitch, powered by 24v, to give the mix demand. I do this as opposed to constant flow. If I were designing around constant flow, I think I would use the indoor sensor to redefine the mix temp. Noted, all of my jobs are slab on grade or gypcrete overpours. If I used more baseboard, I think it would be more responsible of me to design around constant flow.

It seems to me that a better use of logic would be to define the indoor sensor as a high limit and anticipator to know that outdoor temp is coming up at a defined rate, the indoor temp is following suit, and the water temp is then redefined to compensate for both.

Is that a correct way to think about it? People are usually afraid of what they don't understand, I would rather wrestle with it than be intimidated by it.

Any other thoughts?

Regards,

PR

hydronicsmike

Paul...

...as always, you make a lot of sense. Wrestle with it, rather than let it intimidate you.

An Indoor Sensor is great if you're talking single zone. If you have more than one, then it could even create problems. The Supply Water Temperature is always adjusted based on Outdoor and Indoor Condition at the Indoor Sensor (Indoor Feedback). If that Sensor is satisfied, the Supply Water Temperature is lowered to gain continuous circulation. But if you have (sub) Zones with Thermostats, those may not get what they need, because the Controls wouldn't know that all of the sudden there is another zone that might require a higher temp.

Basically, only use an Indoor Sensor in a SINGLE Zone System. If you have more than one Zone, then either use Thermostats or a Zone Control System that can handle Indoor Sensor or RTU inputs for more than one Zone.

I hope this makes sense.

All the best. Later,

Mike

Tim Doran

Ok Paul here goes

The logic goes something like this. When you program the control two of the perameters are Mix Room and Mix Indoor.
Mix Room is the desired room temperature and Mix Indoor is the room set point used in the heat loss calculation. The parallel shift that occurs is a result of the difference in these two points as it relates to supply water temperature. One the high end the limiting factor would be the Mix Maximum. The low end limit is basically when room temperature and supply water temperature are equal.

I have some graphs showing this. I will try to dig them out and post them in the morning.

Tim D.

Wayco Wayne

Why couldn't I

put a constant 24 volts to the input of the 212. Ride the reset curve, using the indoor sensor to adjust the curve parallel when it is off temp. That way it could keep constant flow with the system circ, and turn off when the WWSD is acheived. I've done this with the Tekmar 261 with good results. WW

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Tim Doran

You can

do this with the 212 also. I have had good luck with this as well. In fact this is how I addressed one of Dan's give & get questions some time ago.

Tim D.

peng.shen

Tekmar 250 one stage boiler controler

My system have a tekmar 250. Can some body tell me how can i get a manuel and i can understand more. Seems my tekmar not doing the job it sopposed to do: change the cerculating water temperature when out door temprature change.