Wilo Statos with setback

hot_rod

why not use the variable speed, delta T function built into the drainback solar control? It allows you to use any inexpensive, off the shelf brand of circ.

I have my shop drainback running off a 25-60 Alpha Pro sample circ. 1/2 the wattage that the 15-58 on speed two cost.

I'm wondering that an irradiation sensor would be a better way to start a drainback system, then the delta T function to vary the pump speed.

This same control accepts a CS-10 solar cell.

hr

Derheatmeister

Wilo Stratos with setback/WWSD

Hey Steve and Mark are you bringing the Stratos with the Setback/WWSD over to the USA?

If not, Why? Is there no market place in the USA?

If so, When?.... Can't wait!

Richard. :-)

Mark Hunt_6

Hi Richard


The Stratos and the ECO here in the states have a "set back" function.

On the ECO, dial the head set point on the "Auto" side of the scale.

With the Stratos, you enable or disable the "set back" function in the programming screen by using the red button.

The "set back" feature works with continuous circulation systems that use "night" or "unoccupied" system set back where the target water temperature is reduced for extended periods of time. Normal OD reset fluctuations do not effect the operation of the circs.

The Stratos and the ECO learn the system operation in the first 72 hours of running. After that, the circulators will lower their operating point during those times of set back.

As for WWSD on the Stratos, here in the states you must use an interface module with the External Off contacts.

Remove the jumper between the contacts and run 18/2 wire to a normally open, NON-POWERED contact (OD stat or contact on an OD reset controller). The circulator will have continuous 230 volts and the display screen will be powered constantly, but until the contacts close, the circulator will not spin.

Personally, I would use the External Off module on every Stratos I installed.

Hope this helps.

Mark H

Brad White_203

It is true...

My Stratos Eco purrs along at about 4 feet of head during the day.

At night (the rare times I go down to the basement), it is barely perceptible if it is turning at all, but the pressure gauges on S&R are fractionally different.

In the AM, it ramps right up- we awaken to a toasty house.

Have not quantified the electrical bill yet, at least not broken out for that one item.

Metro Man

Yo Mark

Playing around w/eco and stratus w/drain back. Have you investigated further after our conversations months ago? Have a couple of ideas to prevent the potential freezing these pumps could inadvertently cause. Would need an external flow switch or "double pump" using a high head to start things then switch to var. speed w/ wilo. Maybe if the Wilo's could use external sensors for delta T this may be easier.

Sticking to the KISS principle still is the norm. High head pump then slow flow @ return. Use less power as pump slows but creates internal heat.

Also would love to wire a light in parallel w/ the rotor of pump to shine dim to bright as these pumps speed and slow.



Metro Man

Derheatmeister

WWSD/TRV's

On the ECOS:"The pump automatically responds to the Night setback of the heating system by an electronic evaluation from an integrated temperature sensor."

"During conditions of extreme, continuous low system heat requirement the pump will automatically switch to minimum speed.

How does the Circ know ??

Do you need a programmable room stats with setback to create These "Low flow" conditions?

Is this an US version because we use Thermostats and Zonevalves over here?

And if so how will the "Circ" know if you are using TRV's with no "setback"

So on the Stratos a Simple outdoor reset Controller that will have a open contact on drop below setpoint will activate the circ?

If i just remember correct some of the "Older" Cirs from Wilo had that integrated in them?

Is the interface Module the "Setpoint control?

Mark, sorry but i missed some of the Presentation due to a later arrival on the last Wetstock

Thanks for explaining it.Richard.

Metro Man

slow drain-back

HR, I worry about high head systems with a very slow drain-back time and lots of exterior plumbing. We could be setting ourselves up for a freeze. I have to admit I have yet to try out the resol controller for our drain back systems but will be doing so soon.

EX; very cold outside temps, cold storage tank, enough sun to start things up. Pump slows to maintain delta T. Quick cloud comes out, system goes to drain. I could see an instance where there could be a problem.

I will look closer as to the adjustments and settings for drain back var. speed controls. Until then, we will still be using high head pumps and flow rate adjustments on return.

Metro Man

Derheatmeister

Met roma this is being doen in Europe Minus though Drainback.

Is there not a differential controller that switches from two circ to one circ?

Coming from a None drain back guy!

And Dave U R coming to the ISH ! Jaa !

Metro Man

Dare controller

Yo heat mistro! Happy New Beer! Looking into crystal ball to see if I can swing-ISH. Any goot bier out that way? If not we can smuggle in some Keystone.

The trick is doing it with drain-back. I think you can configure some controls to make the scenario that you described work. But..... if the system switches to low flow, looses head, your low head pump can't get it up (over collectors that is) danger, danger Will Robinson...

The biggest advantage for lowering the flow to a drain-back solar system is during low insolation. You get away from short cycling the pump. But I still would rather have that then worrying of frozen pipes. I will need to test b4 we put anything in the field.

I think a pump with controls that senses flow on return making sure we have flow then times out to allow for var speed and an input for redundant freeze protection would be great.

The old C-30's where great because they had that jumper installed on side of controller. Remove the jumper controller de-energized relay.. EZ to put snap switches throughout system to multiple absorber plates or ....???

Metro Man

Brad White_191

How it knows

My understanding is that the Wilo has an embedded temperature sensor and timing circuit. It "learns" the heating pattern and detects a prolonged drop-off in temperature. Thus it concludes a night setback condition (conversely any low load condition). Pretty simple.

I am sure Mark will correct any misinterpretation and expand upon it if he wants to.

Derheatmeister

Head n Flow

In General how much HEAD do you need to make it FLOW in a Drainback?


No Keystonen sie in Deutschland! We will be trinken Licher Bier from Lich.

hot_rod

yes, either or

that control has both functions, two pumps start, with one dropping out after 5 minutes (adjustable), or variable speed high.

I've been running my drainback with corrugared SolarFlex as the tube, with a coaxial hydro vent it drains in less than 10 seconds, about 30 feet and 4- 4X8 panels.

I've also filled with water and pressurized a section of SolaFlex and left it out all winter. We've seen 4F and no bursting of the tube.

hr

Metro Man

give me flow or give me.......

Total head of system + 5 feet is what we shoot for.

Metro Man

Metro Man

problem

The problem I see is if the high head pump failed. Var speed would continue to run because of delta T. Var speed does not have enough head to reach collectors but water is filled in exterior plumbing or a portion of the solar collectors. Water is not flowing and freezes.

Could look like swiss cheese in a hurry.

Metro Man

Mark Eatherton

How does it differentiate...

between a programmed nite set back and an undersized heat source operating at daily design conditions?

They're out there...

ME

Brad White_191

I would imagine that

the baseline is whatever it is. In other words, an under-sized heat source running full-out becomes the baseline (and maintains the full head/flow relationship).

If and when the load eases, that, I think, would be for an extended period too.

The "overnight" feature that I noticed happens about half an hour after Der Vitodens says, "guten nachten".

Remember, all the circulator does is go to 50% of daytime head. Naturally this cube root function means that the 48 Watts drops to about 7 Watts at night. Yawn.

p.s.: Where are you seeing under-sized systems??

Mark Hunt_6

Answer


It doesn't, the installer does.

The "set back" function on the Stratos and the ECO is optional. You don't have to use it and as you point out, there are systems where you would not want to use it.

Brad's description of how the feature works is correct. It's all based on time(duration) and temperature.

Mark H

Mark Hunt_6

Late again Mr.Spicoli???

No problem Richard.

Brad did a great job of explaining the "set back" function.

It is all based on water temperature and time(duration). Typical systems here the the states do not set back the target supply water temp, they lower the target room temp. In these systems the set back function on the Stratos or ECO will not do anything since they will never see a set back of the water temp. Leave the circs in the "day" mode(Sun icon).

In systems with continuous circulation and a set back control that lowers the target supply temperature for extended periods of time (night or unoccupied) set the circs to "Auto". After 72 hours of continuous running, the circs will have "learned" the system operation and will lower their operating point during those times that the system target water temp is lowered.

"So on the Stratos a Simple outdoor reset Controller that will have a open contact on drop below setpoint will activate the circ?"

Answer: Yes, but you need the interface module with "External Off".

"If i just remember correct some of the "Older" Cirs from Wilo had that integrated in them?"

Answer: I have a European model Stratos on the Brain Box and the WWSD function is not integrated. Still requires the interface module.

"Is the interface Module the "Setpoint control?"

Answer: No. All settings are done on the Stratos with the red button and the Stratos controls itself. There are currently three modules available here in the states. External Off, External Minimum and LON.

The LON module allows the Stratos (Stratos only) to be integrated into a LON building management system. The circ can be controlled and monitored by the LON BMS. (A BackNet module is in the works) There is also a "DP" (dual pump) contact on the LON module. I will explain that below.

The External Off and External Minimum modules each have three sets contacts. They both have 0-10vdc and "DP" and either External Off or External Minimum.

The "0-10vdc" contact allows the Stratos to be modulated by a control that produces a 0-10vdc signal. This is a UNI-DIRECTIONAL contact so no remote monitoring. The installer would still have to program the head set point at the circ as well.

The "DP" contact, or Dual Pump, is used when we have two Stratos in parallel.(Not SERIES) Each Stratos would have an interface module and the DP contacts are connected with 18/2 standard thermostat wire. On initial power up, each screen will flash "MA" or Master. Pushing the red button on either circ will determine which becomes the master and which becomes the "slave". The slave circ will display "SLV" in the screen. ALL programming will be done through the master circ and nothing else need be done to the slave.

You may choose whether you want the circs to operate independently (back up) or together (higher flow requirements). In "back up" mode,(circ[]circ icon in the programming screen) only one circ will operate to satisfy system demand. In the event that something should happen to one circ, the other circ takes over after a 5 minute delay. I should note that in order for this to happen, an actual ERROR must be detected by whichever pump is running at the time. I was told of an instance where a contractor accidentally closed a ball valve in front of a master Stratos while he was insulating piping and left the job without re-opening the valve. The Stratos sat dead-headed for an entire weekend and the building was without hot water. Dead-heading a Stratos is NOT recognized as an error so the back up pump never came on. You can dead-head a Stratos or ECO 24/7/365 without hurting the circ.

If you choose to run the circs together,(Circ+Circ in the programming screen) you still do all of the programming through the master circ. As you know, running the circs in parallel doubles GPM capacity while head capacity stays the same. The Stratos calculates whether it is more efficient electrically to run one circ at a higher speed or two circs at a lower speed.

In either mode, there is an automatic switch between lead and lag circ after 24 hours of actual circulation.

The Stratos have a fault contact built in, no module necessary.

The External Off contact comes from the factory with a jumper. When using the Ext.Off function, remove the jumper and connect the Ext.Off contact with 18/2 wire to a non-powered set of contacts. An outdoor stat that closes on temperature drop for instance or a set of contacts on an OD reset controller with WWSD. Contact opens, the circ will not spin. It remains powered and the display screen is visible.

The External Minimum contact comes from the factory with a jumper as well. When the contact is open, the circulator drops its speed to minimum. The way that I have seen this feature used was when a contractor put an aqua-stat on the return line to his boilers. When the return water temp hit 140 degrees, the aqua-stat contact opened and the Stratos dropped its speed. This kept the condensing boilers condensing for the entire heating season.

Hope this helps!

Mark H