Junction box for furnace

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stickboy1375 said:
Why not use W and a fan sail switch in series with the humidifier?
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sail switches tend to be unreliable and expensive... many furnaces have a 120V EAC (electronic air cleaner) or accessory lead and humidifiers typically come with a 24v transformer and/or humidistat. AprilAire has a nifty "senor" you clamp around the blower wire which has the advantage that on most furnaces it would only turn for heat because cooling uses a different blower speed... but its like $60
 
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LarryFine said:
Mine uses 24v for the little motor, which I grabbed from the R and C terminals. As a bypass type, there is no blower.
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What little motor?
Better read the instructions on the equipment... this would typically screw up your heat anticipator setting on mechanical thermostats not to mention void the warranty on several electronic thermostats, humidifiers and furnaces which all say NOT to do it. :mad:
Remember the solenoid valve in most humidifiers draws a lot more power than gas valve, and even if it didn't the heat anticipator has to be set... if there's a humidistat turning the humidifier on and off it would make that difficult.
 
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stickboy1375 said:
I always use the furnace supplied transformer for humidifiers, but newer units have a humidifier contacts built right into them...
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Always? How did you turn the humidifier on and off?

And yes some newer units have 24V humidifier contacts. I'd guess maybe 40-50%. About 50-60% have an EAC or accessory.
 
DaveTap said:
sail switches tend to be unreliable and expensive... many furnaces have a 120V EAC (electronic air cleaner) or accessory lead and humidifiers typically come with a 24v transformer and/or humidistat. AprilAire has a nifty "senor" you clamp around the blower wire which has the advantage that on most furnaces it would only turn for heat because cooling uses a different blower speed... but its like $60
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Yes, we already talked about the price on the current sensors, that's why I brought up using a sail switch... And what documentation do you have that sail switches are unreliable?
 
stickboy1375 said:
DaveTap said:
What little motor?

I'm assuming he meant the solenoid
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No, I mean the small synchronous motor* that rotates the water-pickup drum. The water level is controlled by a float valve.

We keep the blower fan on 24/7, so there's no real reason to cycle the drum, but I could easily switch it with the gas-valve wire instead.

*I say it's synchronous, and not shaded-pole, because the drum can rotate in either direction each time it starts, like my microwave turntable.
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