Humidifiers and Dehumidifiers - Transformer Keeps dying

:wall:

After the transformer to my humidifier died twice in a row, I decided to install a new Honeywell Humidifier. However, after a month or two, this transformer is dead too! How can I fix this? Has anybody else had this problem? Do I need a diode in the circuit somewhere? If so, where would I get one?

I have an H1008A,D Automatic Humidity Control which says that it "knows when the furnace blower is operating eliminating the need for current sensing relays." (Have hooked up all the wires correctly, I believe) I am assuming that the wires are hooked up to the same wires as the blower motor. Should it instead be hooked to hot and ground?

Any help would be greatly appreciated - I can't afford to blow ANOTHER transformer!

Thanks,
-Dan

Tell us how you have it wired up, or take a photo of it.

Do you have a voltage meter to take a reading to make sure you are geting 24 volts on it?

Yes, I have a volt meter, and I understand the basics, E = I X R. (though that doesn't apply to transformers) That is how I know it's dead. I installed it, and it had voltage when I did. (Actually may have been more that 24V, if I remember correctly) However, I just used the 110 wires that went to the old transformer which was dead. I replaced the whole humidifier, thinking that perhaps the old humidifier had a short and was drawing too much amperage. However, when the new transformer died a similar death, I knew it had to be the furnace. I'm not sure what an AC current going to a motor would do to the voltage. (I was not thinking when I thought I diode would help; I was thinking DC current)

The diagram that comes with the humidistat is poor. 3 wires go to w, g and c. White, green, and common I assume? White and green were easy. Common? Assuming heating common, I hooked it to low voltage hot. Must have been right, because it worked. But, I assume those wires are only for sensing fan operation.

L1 and L2 go to the transformer. (& from there it goes to the thermostat, ect - I had to run 6 wires in all to this silly thing and I didn't even have an outside sensor) So, the question is, what is L1 and L2 supposed to be?! No clue. Hot & ground? Hot on Fan run and ground? I'm assuming that the stupid furnace guys hooked it up wrong, and that + should always be hot. So, my plan is to get out the DVOM and go hunting for a hot wire to hook the transformer to instead of the wire that is hot only when the fan is on. Sound like a good plan?

Thanks for your comments,
-Dan

The common needs to be hooked to either the common side of the trasformer or a ground when you hooke the C wire to another hot and the controller called for the unit to run it was supplied with two voltage sources

What model of humidifer do you have??

I would get that COm wire off of HOT bofore something burns out!

Well, there's one "com" (common I assume) that goes to the transformer. That's obviously ground, as the other wire is hot. So, obviously, common must be another name for ground? I see... this is a mistake, I'll have to change that wire. I'm rather surprised it worked. As these don't supply power to either the humidistat or the humidifier, I assume the worst I could do is make it not work!

On the fan board we read rwygt. Red, obviously, is hot. Which one is ground? T, I assume, which I find has the lowest resistance to ground.

I have a Honeywell HE225 which worked fine till the transformer blew. Which was the fate of the identically wired humidifier before it. At least, identically wired in respect to the transformer which was wired directly to the fan instead of using a switch.

Now, why doesn't everybody just hook it up to the fan instead of using the silly little $30 current sensing switch? (Or, in my case, an overly expensive humidistat - my house is so dry, it doesn't even need one) I can only deduce that hooking it up directly to the fan is not correct and perhaps that caused it to die. So, I'll hook it up before the fan.

Many thanks for your replies!