primary/ secondary piping ( how to wire the primary pump)

aaron_4

1) How long should your Primary loop be in your primary / Seconday pumping designe?

2) In John Siegenthaler book Modern Hydronic Heating 2nd Edition, he talks about sizing the Primary circulator. How do you know what the temperature drop is. He uses 15 in the example.

Thanks Aaron

Dan_15

primary/ secondary piping (how to wire the primary pump)

I'm setting up a boiler with primary/ secondary piping. 3 zones. 2 radiant and an indirect. My question is how do i wire the circ on the primary loop to run whenever any of the secondary pumps come on? I'm using a taco sr504 expandible 4 zone switching relay with priority (If i can).

Steve_35

What are you using to fire the boiler?

Ron Schroeder

Mike

I wire circulator to C1 C2 on Aquastat, then whenever the SR504 pulls in Aquastat C1 will be powered. Think you can also wire it to ZR on the SR504

Dan_15

It's a biasi boiler with a riello oil burner
Thanks fo the help,
Mike

Jed_2

That's the \"Zig\"

with Biasi boilers. You have an L4006 operating control. No C1, C2. So with many control strategy's, you need that exta 120V relay to pull in. ZR does the trick many times, but I've had to add an extra external relay on accasion.

Jed

Dennis

Primary wiring

The easy way is to let it run 24/7 if you are worried about heat loss from the boiler you could insulate the primary loop. You could however use circulator relays with an extra set of normally open contacts in parallel to bring on the primary, if the primary draws more current than the contacts can handle, power an isolation relay to bring on the primary. The boiler can cycle based on the high limit setting or the reset temperature.

Dan_15

Thanks for the help, If I try ZR Do i leave the jumper in?
Mike

Ron Schroeder

Mike

If I remember right yes try page 23

http://www.taco-hvac.com/uploads/FileLibrary/100-9.0.pdf

kevin coppinger_4

if you use an....

HW 8148 tie the primary in of the c1/c2 on that relay every time tt is made that will go on...that simplifies a lot....kpc

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