Zvc403 capabilities. Will this work?

Noobieelectrician

Hello all, let me give my gratitude to you before I start for taking the time to read and help me out. I've tried to find the answers on my own but couldn't find anything clear enough....

*Background can skip*
I own a 3 family home that has 3 zones(1 for each family/story). Unfortunately, a previous plumber removed the zone valves and zone control board and the whole building is now being heated by one thermostat although each family has a seperate thermostat and seperate piping. 
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My old b and g nfi100 circulator seems to finally be on its way out and I figured while I'm replacing the pump(going with a taco 0010) I might as well reinstall the zone valves and zone control board. I'm looking into getting the taco zvc403-4 control board paired with taco 571 zone valves and three ecobee lite thermostats... Here is where I ran into speed bumps in my research. (Suggestions welcomed)

The zvc403 comes with a transformer capable of 40va according to taco documentation..which is ~1.9amps. each zone valve uses .9 amps... This already seems to be over the threshold without the thermostats.... Why would they sell a control board for 3 zones if it's not capable of of powering 3 zone valves... I might be misunderstanding. If someone can explain if this would work and how I wouldn't greatly appreciate it.. I'm figuring I need to add another transformer to get to 80va or go with a bigger control board although I'm only using 3 zones..

Thank you again

EBEBRATT-Ed

That would be a good question for Taco. They hang out here sometimes. The valves as you say are .9 amps each. Taco says in their literature that 3 valves will run on a 40 va trans

Maybe they will respond

hot_rod

The theory with high draw actuators is the will not all hit at the same time and overload the transformer.

Know the the Caleffi ZVR allow you to snap in a second transformer to get 80 Va on all the versions, simple molecular plug to wire. They are also 80 Va across all connections nor 40 on 1/2, 40 on the other half.

Zman

The Taco zone sentry valves draw .48 amps each.
How did you determine that the 0010 is the correct circ?

Noobieelectrician

Zman said:

The Taco zone sentry valves draw .48 amps each. How did you determine that the 0010 is the correct circ?

Thank you all for responses. I pretty much compared the pump curve/specs and whichever was closest to my original.. the 007 didn't really match up that well. The 0010 was almost identical with a slightly higher head. The port to port length is also the same at 6 3/8" Was I incorrect in this method?

I will look into the zone century valves. I was planning on the 571s as a recommendation from someone.

 hot_rod said:

The theory with high draw actuators is the will not all hit at the same time and overload the transformer.

Know the the Caleffi ZVR allow you to snap in a second transformer to get 80 Va on all the versions, simple molecular plug to wire. They are also 80 Va across all connections nor 40 on 1/2, 40 on the other half.

Thank you for that recommendation... I will look into that control board. 

I was under the impression that it would constantly pull 0.9 amps to either stay opened or stay closed.. is it actually only pulling 0.9 amps when it switches to either closed or open? If that is the case then I also would see no issues with 40va. I would still probably run an external transformer for the thermostats though

Zman

The 0010 is a low head, high volume circ. They work well on gravity conversions and mono flow setups with larger pipes. Probably not the best selection for typical 3/4" baseboard systems.

Noobieelectrician

Zman said:

The 0010 is a low head, high volume circ. They work well on gravity conversions and mono flow setups with larger pipes. Probably not the best selection for typical 3/4" baseboard systems.

What would you recommend as a replacement? I have not yet purchased the pump. I have a b and g series 100 #106189.. max flow 33gpm. Max head 8 and 1/12 hp

Thank you again.. I also looked into the zone sentry valves and will definitely be going with those. 

Zman

What type of system do you have? Bigger old pipes or smaller individual zones? Approx how far is it the farthest radiator?

Dave H_2

The 571 zone valves actually "oscillates" the power draw so that you do not have a full power draw continuously. The math doesn't seem right, but that's how its designed, you can use three on a 40 va transformer

Noobieelectrician

Zman said:

What type of system do you have? Bigger old pipes or smaller individual zones? Approx how far is it the farthest radiator?

I have my boiler setup on the ground floor with a single circulator.. each floor has its own supply and return of 3/4" piping(all open as a plumber in the past removed the zone valves) The ground/1st floor baseboards are about a foot below the circulator. The 2nd floor is about 8ft above the circulator and the third floor about 18ft above the circulator. The ground floors furthest baseboard is about 30ft from the circulator horizontally. The second floor is the same 30ft horizontally plus the 8ft vertically. The third floor is also the same 30ft horizontally plus 18 ft vertically. Hope that makes sense and again thank you... 

HomerJSmith

I would think this thru. Taco Sentry Zone Valves would be my choice. They have a high CV which means that they have a low resistance to flow. They also have a low current draw because they operate with a charging capacitor and they have indicator LEDs.

I would think you would need a Taco or Caleffi Zone Control.

I would also look into a Grundfos Alpha 2 ECM pump or one of the other ECM manufacturer's line. It will save on energy. The choice would dictate that the pump would provide the flow in gpm for the most restrictive zone, the one with the highest pressure loss. A Caleffi DirtMag with an ECM pump is essential.

The thermostat in each place must be wired into the Zone Controller to moderate the heating.

The B&G 100 had one of the flattest pump curves around. It was an excellent choice with zone valves. Technology has changed.

Noobieelectrician

HomerJSmith said:

I would think this thru. Taco Sentry Zone Valves would be my choice. They have a high CV which means that they have a low resistance to flow. They also have a low current draw because they operate with a charging capacitor and they have indicator LEDs. I would think you would need a Taco or Caleffi Zone Control. I would also look into a Grundfos Alpha 2 ECM pump or one of the other ECM manufacturer's line. It will save on energy. The choice would dictate that the pump would provide the flow in gpm for the most restrictive zone, the one with the highest pressure loss. A Caleffi DirtMag with an ECM pump is essential. The thermostat in each place must be wired into the Zone Controller to moderate the heating. The B&G 100 had one of the flattest pump curves around. It was an excellent choice with zone valves. Technology has changed.

Definetly going with the taco sentry zone valves after some research. 

Honestly would not know how to size a pump correctly, was just planning on replacing with something similar to what was already there. Only picked the 0010 because of the curve similarities with my existing b and g.  Need to do more research if i should just get something similar..

hot_rod

Noobieelectrician said:

Zman said:

The Taco zone sentry valves draw .48 amps each.
How did you determine that the 0010 is the correct circ?

Thank you all for responses. I pretty much compared the pump curve/specs and whichever was closest to my original.. the 007 didn't really match up that well. The 0010 was almost identical with a slightly higher head. The port to port length is also the same at 6 3/8" Was I incorrect in this method?

I will look into the zone century valves. I was planning on the 571s as a recommendation from someone.

 hot_rod said:

The theory with high draw actuators is the will not all hit at the same time and overload the transformer.

Know the the Caleffi ZVR allow you to snap in a second transformer to get 80 Va on all the versions, simple molecular plug to wire. They are also 80 Va across all connections nor 40 on 1/2, 40 on the other half.

Thank you for that recommendation... I will look into that control board. 

I was under the impression that it would constantly pull 0.9 amps to either stay opened or stay closed.. is it actually only pulling 0.9 amps when it switches to either closed or open? If that is the case then I also would see no issues with 40va. I would still probably run an external transformer for the thermostats though

Here is a look at 3 common types of zone valves, showing the current draw. The 570 Taco is unique in that every 15- 17 seconds it draws than .9- 1.2 amp as it cycles.

Different features on different types of valves, spring return are by far the most common, simple, reliable, most are 7- 8 Cv, plenty of Cv for 3/4 & 1" flow size. Some installers like thermal actuator type as they are completely silent. High flow or high shut off pressure is best with a motorized ball type.

enosez

Just a thought as to why the previous plumber piped it all on one thermostat. The previous owner Did NOT want the tenants to be able to control the temperature. 

Not sure if you live in the house and rent the other two floors or if this is a total rental but I would not allow the tenants to control the temperature.