Grundfos Alpha Getting Some Help?

Ronbo

I just installed an Grundfos Alpha 15-55 on my four zone primary secondary system.. When set to Constant Pressure 3 it is rated 12ft head and 7 flow but im getting a flow of 13. When I set to speed 2-3 or constant pressure1, 2, or 3 and the auto adapt it also reads 13 flow. What gives? My head of longest zone is between 10.5 and 12 for sure. I would like a flow of 7 total split between all the zones pipes and when set to speed 1 i get that but is this a problem leaving on this setting since the pump is rated for head of 3 and flow of 11 on this seting?

Am I getting help from the boiler's (pumpTaco 0014) from behind even though I am piped to spec on the Weil Mclain ultra 155?

Zman

Sounds Like

Sounds like the 0014 is "helping" How are your closely spaced tees oriented? How much straight pipe on each side?

Ronbo

Maybe

I have the manifold from weil mclain so the spacing of tees is on the money....from the supply side I have the expansion tank connected right to the manifold so about 12" from tees I have the tank and air separator then 3" nipple then my Grundfos pump another 12" to my four zones coming off , all run with 1 1/2 header with zones 3/4 running off.

It does work well at lower setting after all giving me what I want when set to lower speed 2. So as long as the flow reads what I want then the head is most likely good also?Or will it have issues at start up? Im a newbie by the way. Im assuming the pump is helping with both the flow and head, Yes? It just as well then because this pump will much less power also. It does react well as zones open and close. Its giving enough flow for 3 gallons per zone. As a zone closes the pump reduces flow by 3 gallons. Ty for any help by the way , you guys are great.

chapchap70

can you choke it down?

The alpha I put in is on a manifold with other circulators.  In order to get similar flow in different situations, I had to choke down a ball valve because I was getting too much flow when other circulators came on.  I have the Alpha at a constant pressure setting since the Auto Adapt gave me a flow of between 0 and 10 gpm depending on what was happening elsewhere.



Edit:  Are all your zones downstream of your 0014 circulator, or are some piped direct?  If they are all after the 0014, I don't see why you couldn't leave it at the number 1 setting if the flow is correct for all situations.  Before I installed an Alpha, I never knew the flow rate of a system I was working on; now I just have to assume that the Alpha display is correct because I have nothing to compare it with.

meatball

ALPHA on constant pressure

This will ride out along the curve based on the pressure you set. If you look at the curvem it is a long straight line with multiple gpm's along the way. If you desire a SPECIFIC rpm in a loop, I recommend using the ALPHA in conjunction with a Danfoss ABQM (pressure independent control valve) You can dial in the rpm you want (even use an actuator as a zone valve if needed)