HELP Door chime transformer is kicking my butt!

I'm just short of pulling out what little hair I have over this. I've been searching on the internet and on this site for any clue as to why I can't get this stinking thing to work. I have a door chime transformer that has three voltage options (8v10A, 16v10A and 24v20A) like this. When you combine the 8V and 16V you should get 24V which is the case when I touch my black and red cable on my multi-meter directly to the transformer with power applied. As soon and I combine those two onto what I have set up as my 24V terminal strip, I get a reading of zero and the transformer starts to heat up. How am I supposed to get 24V to my Auber controls and to my switches like this?

Here are a couple pics of my wiring:



Close up of the transformer:



The color of the wiring is ambiguous.

Two of the leads coming from that strip go one each to my Aubers and the other two go to a three position switch. That way I can switch on my honeywell furnace valves when I need to bypass the PID's. My system should end up being almost identical to jlandin's and this thread.

All of that to say...can anyone help with the transformer wiring situation? Why am I getting zero volts when combining those two wires? Thanks for any help.

 

Are you shorting the 2 outputs of transformer together? You are measuring 24vac between which two terminals?

It appears that you are shorting the secondary.

 

It looks like you are shorting out the transformer by connecting them together on the bus. One should be positive and the other negative. You need two 24v buses.

 

Is the transformer supposed to change the phase of its outputs to be opposite of eachother? That's the only way I know of to get a 24 voltage with 8V and 16V.

Even if it does do that, I think you're shorting them together like raouliii said. I believe you'd have to have a separate wire going to your device for each voltage. I think what you've done there is given the other wires 16V and a sort between your 16V and your 8V which might be hurting your transformer. I'm not sure if you can use that transformer for what you're trying to do. I'd get a transformer designed to take 110V to 24V only.

 

It's likely just a 24vac secondary with a center tap @ 8/16. 24vac is the voltage between the two terminals.

 

Yeah, without a doubt you're shorting the output together... hence you'll read zero potential across it.. Like others have said, you'll need a positive 24VAC plus a 24VAC return.

 

Wouldn't they have to be out of phase with each other for the potential between the two to actually be 24 vac? I may be mistaken but I'm pretty sure that's how you end up with 220V in your house. Two 110V sources 180 deg apart so that the two potentials oscillate to be at 110V and -110V at the same time to give a difference of 220V.

 

Household 220vac is created basically the same way. It's better to consider it a 220vac source from a transformer. Neutral is the centertap of the transformer providing 110vac between hot & neutral. The centertap of the 24vac transformer just happens to be de-centered.

 

It looks like this transformer probably won't work for me then. There is no positive/negative post on the Auber controller as per page 5 of this instruction manual. The way it reads to me is that you have one 24V source coming into the controller on pin 13 and when the temperature reaches it's threshold, it kicks the relay and pass voltage to pin 14 which can then go out to my honeywell furnace valve. In my case, it goes to a 3-position DPDT switch.

Like this:



You can see the connections a little better here:

 

If 24vac is needed for your valve then the transformer you have should work. The controller & switch should be switching 1 leg of the 24vac source. The other leg should be connected to the valve. You are currently shorting the output of the transformer. You must keep the two leads from the transformer separate.

 

For instance, I could send the 8V leg straight out to the valve and have the 16V leg go to the PID for switching?

If I were to get this transformer, would the two wires coming out of the secondary side be wired similarly...one to the valve, the other to the PID?

 

This might help. Don't think of it as 8v & 16v but only 24v.

Separate the transformer outputs as 24vac & 24vac Return.

Wire pid terminal 14 to one lead on valve. Wire 24vac to common terminal of pole1 of dpdt switch. Wire AUTO terminal of dpdt pole1 to pid terminal 13. Wire MANUAL terminal of dpdt pole1 to pid terminal 14.

Wire 24vac Return to common terminal of dpdt pole2. Jumper AUTO & MANUAL terminals of dpdt pole2. Wire AUTO terminal of dpdt pole2 to other lead of valve.

I assumed your switches are dpdt (on-off-on) type.

 

Yep they are...Thanks! I'll give it a shot today.

 

The pid functions as a simple switch in the valve circuit. The dpdt switch either interrupts the circuit (off), enables the pid switch to control (auto), or bypasses the pid (manual). Using both poles of the dpdt allows for isolating the valve completely from the 24vac. Good luck.

 

CollinsBrew,

It's been mentioned a few times so far. Your transformer is dead shorted with the way you have it wired.



You need to reconfigure the way you deliver the power to the devices involved.

I hope this helps.

 

Ok... I messed with your picture a little bit and configured the wiring so that you will no longer have a shorted transformer. As best as I can follow your other wiring from the pictures, I think this change will get you where you need to be. (However, be sure to check it out before powering up again.)






I sure hope this helps.

 

Thanks P-J. If I break the strip where you have it in the pic as my wiring is now, the two black lines go to pin 13 on the PID and the two red go to the manual side of my switch. Wouldn't I have to jumper that over to the AUTO side of the switch somehow to complete the circuit?

 

Wouldnt it make more sense to replace the neutral with one of the phases?
Assuming the rest is wiered correctly ofcourse

 

Collinsbrew

Are you working from a schematic or wiring diagram of some sort? Your pictures don't give a clear layout of your wiring to the pid, switch and valve. There are a few different ways to wire your setup. If I knew where your starting point was, I can certainly help you sort it out.

"Black to pid terminal 13". What is connected to pin 14 of pid?

"Red to manual terminal of switch". What is connected to the other two terminals of that pole of the switch? What's connected to the 3 terminals of the other pole of the switch?

What are the two leads to the valve connected to?

 

The neutral to the valves? I thought about this and asked the question in some other threads about the TH and TR post on the honeywell vr8200 valves. I could run one leg to the valve and just have the other go where I currently have it. When the PID switches it will complete the circuit and would do the same when I move the switch to the MANUAL position.

 

You need to review your wiring to and from the PID terminals 13 and 14.

This wiring setup from Auber Instrument should be followed.

If you have additional switches in that circuit then you need to decide how and where to place them.

 

You cannot use the 120V power neutral on your 24V control circuits. Do not do this. You must use the 2 output lines from your 24V transformer to provide a complete circuit.

 

P-J...I just did exactly what you pictured but instead of all of those leads going to my switches, the second lead goes to the TH post on the valve. Now, when the PID kicks on or when I move the switch to manual, full 24V goes to the valve and it kicks on. So, essentially, all I had to do was move my two negative wires that were going to the valve from the neutral strip over to the second leg of the transformer. Finally, I'm going to get to make some beer again!!

 

That set up from the instructions is how I have the PID wired. I have one leg of the transformer going to pin 13 and then out of pin 14 I have a lead going to the auto side of my switch.

 

CollinsBrew,

Sounds like you did good. Anyway, I had not checked in on your thread because I was busy making a diagram for you so that it might be a little clearer.

I hope it clears up some things for everyone watching your thread.

P-J

 

PJ. Great diagram. That should work just fine, however, I have a sneaking suspicion that it's not wired that way yet. As I mentioned, there's a number of ways to wire it.

 

IT LIVES!!! Thanks for the help guys. Here's what it looks like now:



and the PID's and switches: