Grundfos Alpha 2 Wiring

Le John

I want to wire the Alpha 2 to a Taco Zone Valve controller and since the alpha's display is always on what is the recommended method to wire it to the Zone Valve controller?

Zman

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.

Solid_Fuel_Man

I too like to see everything turn off when not in use!

Big Ed_4

I thought the Alpha had a memory

Le John

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?

SuperTech

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.

Le John

thank you @SuperTech - I can add an outlet for the pumps line cord but how will that get wired to the ZVC404?

Zman

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.

SuperTech

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.

Dave H_2

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.

Grallert

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.

Dave H_2

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.

Solid_Fuel_Man

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.

Le John

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.

@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

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.

hot_rod

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?

SuperTech

The Honeywell L7224U has pump cycling built in, as does many condensing gas boilers

Le John

Doesn’t the Taco ZVC have this built in to the control? It is wired to a Lochinvar Noble Combi.

hot_rod

Le John said:

Doesn’t the Taco ZVC have this built in to the control? It is wired to a Lochinvar Noble Combi.

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..

Solid_Fuel_Man

Shouldn't let the pumps "rub" for 30 seconds after 72 hours of non operation😁 think I found a typo hot rod.