Grundfos Alpha 2 Wiring
Comments
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If you turn off the pump, the auto adapt feature will reset each time. What you are suggesting will work just fine in the constant pressure or fixed speed modes. Just cut the cord end off and wire it to the controller."If you can't explain it simply, you don't understand it well enough"
Albert Einstein
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I too like to see everything turn off when not in use!Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
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I thought the Alpha had a memory
There was an error rendering this rich post.
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On the ZVC 404 isn't the power to the circulator interrupted when there is no call for heat? How would the display illuminate when there is no call for heat?0
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You can leave the Alpha 2 powered up all the time, that's why they have the version with the line cord that you can plug in. The Alpha 2 will slow down and stop as the zone valves close. I use it like this on my boiler. The Alpha 2 does have memory as well for on and off applications. I have used it like that as well.0
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thank you @SuperTech - I can add an outlet for the pumps line cord but how will that get wired to the ZVC404?0
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If you want it on all the time, you don't need it connected to the ZVC. The alpha will detect when a zone opens and start pumping."If you can't explain it simply, you don't understand it well enough"
Albert Einstein2 -
That's pretty much it. It's designed to be plugged in, left on auto adapt and forgotten about. For people like me they built in constant speed and constant pressure modes to play with 😀. It's a nice pump but I believe it still has room for improvement.1
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If everything is off and not calling for heat, why would you need to see the display? The most efficient circulator is the one that is off.
Cut the plug off, strip back and wire it to the ZVC.
Dave H.Dave Holdorf
Technical Training Manager - East
Taco, Inc
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I've done it both ways, cut the cord and wire to a control of some kind or simply plug it into an outlet. If you wire it to a control it will wake up to a brand new system every time it's powered and have to relearn that system over and over again. If 6you simply plug it into an out let it will power down when there is no call and retain its adaptive memory. It really should have a constant power supply. With all the zones closed you'll see that it's using no or very little power and moving no water the way it was designed.
Miss Hall's School service mechanic, greenhouse manager, teacher, dog walker and designated driver
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If its being used in a zone valve application, it shouldnt be in the autoadapt mode, it should be in the constant pressure mode so there is nothing to learn.
the autoadapt mode should be used with thermostatic radiator valves.
So powering down after use will not affect the performance of the circ.
5 watts is still 5 watts.
Dave H.Dave Holdorf
Technical Training Manager - East
Taco, Inc
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I agree, I dont like the deltaP pumps running at a minimum speed just waiting for a valve to open. I'd rather power it down.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
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@Solid_Fuel_Man if using the plug - does that mean the pump is always running even though the zone values are closed? With all zone values closed is it actually moving any water?Solid_Fuel_Man said:I agree, I dont like the deltaP pumps running at a minimum speed just waiting for a valve to open. I'd rather power it down.
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Yes, it is spinning. Not moving any water, its keeping the differential pressure to "see" when a valve opens. Otherwise it's just a pump upstream of some valves.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
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Another option was to wire it through a Caleffi relay which will exercise the circulator occasionally throughout the "off" season.
Possibly some of the boilers also have that exercise function built into their on board controls?Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
The Honeywell L7224U has pump cycling built in, as does many condensing gas boilers0
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Doesn’t the Taco ZVC have this built in to the control? It is wired to a Lochinvar Noble Combi.0
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Usually there will be a DIP switch on the board to enable an exercise function. Here are DIP switch options on the Caleffi ZVR, it varies from brand to brand, as to the features and functions..Le John said:Doesn’t the Taco ZVC have this built in to the control? It is wired to a Lochinvar Noble Combi.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Shouldn't let the pumps "rub" for 30 seconds after 72 hours of non operation😁 think I found a typo hot rod.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
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New to the forum. Found this thread and had similar question. My daughter has a Navien 240E combo unit with the Grundfos Alpha2 circulation. (about 3 years old) This past week no heat but domestic water was fine. The pump was wire directly to the Navien unit. When heat was called for, the LED's on the pump would flash but would not stay on. To confirm if pump was OK I disconnect the pump from Navien unit, installed a plug on the cord and plugged into a wall receptacle. Pumped worked fine, turned on thermostats to call for heat and everything worked. Left it plugged into the wall so they could have heat. Is it OK to leave like this? Still don't know why it wouldn't power up from the Navien unit.
Note: They had a technician look at it when the problem started. He left and they assumed he was getting parts for repair but didn't return and haven't been able to contact him. I went the plug route so they would have heat but would rather not leave it this way without knowing what the problem was. Any thoughts on the issue with no or intermittent power to pump from Navien unit?
Thanks and sorry for long first post.
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More than likely it is ok to leave like this for the season until its a little less cold and more readily serviced. I had a similar situation last winter with my old boiler, the pump relay in it was intermittently cutting out. mine was a little different as it was both pumps (boiler and zone pump) both had regular power plugs so I just plugged them into the wall for the season since I was planning a whole new boiler that spring anyway. Since the water will circulate even when there is no call for heat it can somewhat change how the rooms feel if you have any zones that are "always on" like I do
You could just have a blown fuse in the boiler, or whatever relay board powers the pump may be fried.
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Is it on a zone valved system !
do you know what setting it is in?
In AutoAdapt it will just ramp down to around 7 w in a standby or idle mode
Leaving them always powered allows the exercise feature to work durning off season
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Thanks for the replies. I only have a basic understanding of these system so forgive me if I write something stupid. The heating side has 5 zone valves that provide heat to up and downstairs. I confirmed that all zone valves work. Each would call for heat when turned on individually. Each would cause the LED's to flash on the Alpha 2 pump. Sometimes it would stay on for a minute or two and then shut off even though the call for heat was still there so I wouldn't think that it's a blown fuse more likely some intermittent communication issue in the main board or some sensor.
The pump is set to Auto Adapt but does work with the other settings. With all zones off it shows 0-GPM and then go to 1-3GPM with one or two zones on and I believe 9-10 GPM when all zones on. (I'm now back home on Vancouver Island and my daughter and family are in Vancouver so I can't confirm the exact numbers)
I did confirm on one occasion when it stayed on for a couple of minutes that when the zone temperature was reached the LED's on the Alpha pump would go out so no power to the pump if the zone temp was met. Assume that this would be normal with the pump hooked to the Navien unit and not like it is with it plugged into the wall, where the LED's stay on all the time and just shows 0 GPM when zone heat have been met.
Again, thanks for your comments. I feel better knowing that it's probably OK to leave it plugged in directing to the wall outlet until they can find another technician to look at it.
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1, 2& 3 are fixed speed settings. In Auto or the 3 right hand settings, mine never goes to 0 gpm? There always needs to be some movement so the pump knows when to ramp up on a zone call.
When it reads 0 gpm, what is the watt readout. If it reads any watts it must be turning?
I would not put a lot of trust in the gpm, it is a calculated value, not an actual flow rate.
I think this was an OEM model, so it could have a specific algorithm
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Can't recall what the watt reading was at 0GPM other than it was low. The pump was probably not turning fast enough to register a GPM readout. I will ask them to confirm as I'm now curious to what it was.
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I think the gpm is a calculation based on rpm and current draw of the motor, calculated in the microprocessor.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream
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Confirmation back:
When it shows 0-GPM it is showing 6 watts so maybe not enough flow to register 1GPM consistently.
2 Zones on and calling for heat it's showing 19 watts and 4 GPM
5 Zones on, all calling for heat, it shows 43 watts and "HI" as GPM which according to the manual means you are over 12-GPM.
Assuming that all of this makes sense and within the normal parameters.
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Yes that sounds correct. I pulled a pump out of the body, held it in my hand to observe that low current draw, low rpm condition.
With the Alpha 15-58 connected to the GO app you can watch the rpm. Lowest I got was 2154 rpm, at 3W.
Highest was 4300, 38W.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1
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