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Multiple zone valves (6 Posts)

• Multiple zone valves

I'm trying to calculate how many zone valves I can put through a 40va transformer. If I take the zone valve motor amp rating and multiply by 24 volts, divide that total into 40, that's the answer (right)? Now I'm looking at a honeywell zone valve and it reads the following: 24vac 50 va pilot duty 120vac 4.4 amps full load 28.4 amps lock rotor. Which number do I use?
• Which Honeywell

zone valve are you using. The numbers you posted seem like relay numbers not Honeywell ZV's. If memory serves me Honeywell ZV's use about .2 amps so you can use 5 of them with a 40 VA transformer. If you are using a NEMA rated class II standard DC20-92 transformer you can exceed rating up to 200%.
• Tim

Would you be so kind as to show me how you calculated that? Or tell me what I'm doing wrong. The .2 amps is a 5th of an amp; 24 volts divided by 5 is almost 5, so each zone valve is drawing 5 va; 40 va divided by 5 va is 8 zone valves. There's probably a de-rating in there somewhere? Alan