Aprilaire 700 Wiring Help

Patrick29hansen

I've never posted on a forum like this before, so please be patient with me! I also know my problem sounds stupid because I've been reading threads and random posts for the past two days trying to find a solution on my own, but I just can't find any real solution. Here's my problem:

I installed an Aprilaire 700 (with the automatic digital control model 60). Everything works great, except that the humidifier water and fan run whenever it calls for humidity, and has no regard for the furnace blower. I does have the "blower activation" switch, but having it on or off makes no difference. From what I've found so far, I PROMISE I have it wired correctly according to the directions, but obviously something is different.

From what I have read, it seems that it's running all the time because I have the "R" and "C" constant 24V from the furnace terminal connected directly to the humidistat, as the Aprilaire instructions clearly say to do. It even says that if it doesn't get constant power, it may not work correctly.

The only other reasonable idea I've seen so far is to run the "R" on the humidistat to the 120V "HUM" lead on the furnace (with a transformer). Does this seem like a better setup? And if so, why does the diagram clearly show something different? Finally, where do I get this transformer, and what exactly do I ask for? The transformer that came with the humidifier is installed in the "H" terminal on the humidistat as indicated in the Aprilaire diagram pictured below. Please help!

Attached Thumbnails

 

diyorpay

This website may have useful info:

http://www.alpinehomeair.com/viewpro...ctID=453058472

See Documents tab

Aprilaire 58 Installation Instructions, figure P looks relevant

beenthere

DO NOT connect R to 120 volts, or you WILL burn out the control.

Are you sure you have the controls G connected to the thermostat G, and the controls GF connected to the furnace G.

beenthere

DO NOT connect R to 120 volts, or you WILL burn out the control.

Are you sure you have the controls G connected to the thermostat G, and the controls GF connected to the furnace G.

raylo32

It was not stated that clearly but he was talking about connecting the 24vac transformer to HUM then the output of that to r and c, not directly 120v to r and c.

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jagans

This may sound rather simplistic, but why dont you just turn the furnace blower fan to ON and leave it there. This way you will have constant filtering of the air, and constant humidification as needed. Just be religious about changing the filter. The HVAC pros might have some cons about doing this, but continuous cleaning of the air is a good thing, IMHO.

Patrick29hansen

Thank you all for the input.

First off, beenthere - I would never connect 120V to the control, it would be with a 24V transformer. And yes, I am absolutely sure that my thermostat G goes to control G and that control Gf goes to furnace G.

Second, jagans - I'm not opposed to leaving the fan on all winter, but my humidifier is in my unfinished basement, so if I let it run all the time, the humidifier's fan will always be blowing cold air from the basement into the system which will make the furnace operate more frequently and thus cost more to run.

It really seems like something isn't working correctly on the humidifier control. So, diyorpay, using diagram P from the link you sent, it shows "W/G" and "Cf" on the diagram. How does that translate to the "W" and "G" terminals I have on my control? It seems that I'm missing the common lead in this case. Otherwise, I'm expecting the thermostat G or the furnace W to act as the common.

So. . .What about diagram L from that same link? Again, how do those terminals translate to what I have? If I use diagram L, should I put G on the thermostat back on G on the furnace, run the control's W to the W on the furnace, and run the G on the control to the C on the furnace?

Thank you all again!

beenthere

The 700 doesn't draw any air from any place other then the furnace. It can draw basement air.

Patrick29hansen

The 700 has an external fan that draws air through the evaporator pad into the duct work. This is the only feature I don't really like because it draws unfiltered air into the system which then gets blown into the rest of the house.

raylo32

No, the 700 uses its onboard fan to draw warm air out of the supply plenum blows it across the media pad, then blows it back into the other side of the opening into the supply plenum. IOW the air comes and goes from the same pressure area with its fan providing the motive force. It does not pull in unfiltered air from the room.

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beenthere

Don't know where you got that from. It only draws air from the duct it is installed on, and then blows that same air back into that same duct.

diyorpay

http://www.alpinehomeair.com/related...HC_install.pdf

Figure K or L but see differences for 700 old/new models.

Sorry if this duplicates what came with the 60 instructions.

beenthere

Also, make sure you don't have the wires on R and C reversed. It is polarity sensitive.

raylo32

Thanks for posting the latest manual. I guessed they had changed the 700 with all the questioners talking about them coming with a supplied external 24 vac transformer. I have the old almond one with the internal transformer. Now I know. :-)

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Patrick29hansen

I wired it according to Figure K, and R and C are correct from the furnace. I apologize for not knowing that the 700 only recirculated air inside the plenum. I assumed that will that large of a fan and the open slats on the part that hangs off of the duct that it was simply blowing room air across the media and into the plenum. I Don't know exactly how it works, but I see that you're obviously right.

However, this still only leaves me the option of leaving the blower on all winter, right? I just seems that when wiring according to their diagram, it should operate as advertised. I open to any other ideas!