Do I have enough VAs?


  #1  
Old 04-16-18, 07:33 AM
G
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Do I have enough VAs?

Background:
  • I have a 5-Zone system run by a Aquastat Relay: L8148E
  • I recently swapped-out 4 of 5 Boiler T-Stats from Mercury 2-wire to a HW Wifi RTH6500.
  • I'm successfully using Ventstar 2 Wire Kit at each of T-Stats, but now tired of looking at the wires hanging from the wall.
  • Zone Valves are Taco. I was not able to find Part#, but it says "3 Zones - 40VA transformer"
  • I have 3-wire installed behind walls. G-wire is not attached to anything on either end.
  • At the boiler, I have (2) 24V - 40VA Transformers wired red-to-red/white-to-white
After reading other posts on this forum (see trackback - my wiring footprint is exact same) I'm comfortable with how I can rewire from the furnace and supply power (G to C) to my T-Stats using the G wire, but what I'm not sure of is if I have enough VAs from the Transformers to supply my 5 T-Stats and Zone Valves.

If I'm doing the math correctly, between the two Transformers, I have 80VAs, of which the 5 Taco's require up to ~67VA's, leaving me with up to ~13VAs for (5) RTH6500 T-Stats. Will my current Transformer configuration support this, or should I wire-in / replace my (2) Transformers with 60VAs each?

Trackback:
https://www.doityourself.com/forum/t...ssistance.html
 

Last edited by Gatorman11; 04-16-18 at 07:36 AM. Reason: adding visible trackback
  #2  
Old 04-16-18, 05:33 PM
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Welcome to the forums.

The two transformers are used as separate circuits. Should be two zone valves on one transformer and three on the other. The 40va will run two valves and two wifi stats just fine. The transformer with the three valves should be upgraded to a larger one. I'm not aware of 60va models but there is a 75va transformer.
 
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Old 04-16-18, 06:50 PM
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Thanks PJ.

I definitely might be wrong, but I think they are wired in a series right now... see picture. So, to confirm, you think I should split them up?

https://drive.google.com/open?id=0B7...pKUDFCcGdjRG0w
 
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Old 04-16-18, 08:44 PM
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I can't have two threads running on the same topic. Normally I'd merge them but the time/order would be confusing. So this one will be closed and we'll continue.....HERE
 
 

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