problem with an older AAON unit form 1992

[JBM1000]

I've just had the ghost seem to raise it's ugly head and the only way out is refrubish the circuit with new coil loads and even the t-former. Sometimes the ghost really is just "In The Machine" to quote the band The Police!

[2muchinfo]

does the unit have a smoke detector? we just had an aaon chatter relays and contactors intermitttantly because the smoke detector was pulling in and out.

[newyorkjets]

Problem solved... there was multiple contactors in the heating circuit that were causing a voltage drop on the low voltage side.

[ryan1088]

Problem solved... there was multiple contactors in the heating circuit that were causing a voltage drop on the low voltage side.

I bet you'll be back and see that problem again.....

[newyorkjets]

I bet you'll be back and see that problem again.....

well do you have any suggestions as to what could be causeing the problem?

[newyorkjets]

I bet you'll be back and see that problem again.....

well do you have any suggestions as to what could be causeing the problem?

[ryan1088]

The few times I saw this problem, all of them had very long runs to the thermostat. The inside panel clearly states how many feet of stat wire you can use before you need to upsize. In our case, we were 3 times over on length and it had regular stat wire ran to the stat. Voltage on the secondary was about 22 volts even with new transformers.

[newyorkjets]

The unit did have small diameter stat wire that had been spliced in one spot originally installed. When i seen this i did change out the stat wire. I did check the voltage at the coil after the repairs were made and had 25 volts. The stat is about 40 to 50 feet away from the unit... i didnt see anything saying a minimum distance... do you remember what it was?

[ryan1088]

How many conductors do you have running to it?

Here's the chart in the iom:
200'= 20 ga
350 =18
500 =16
750= 14
1250= 12

[newyorkjets]

there are 7 conductors

[ryan1088]

So 7 conductors and a 50' run would need 18 awg wire.

7x50=350

[newyorkjets]

well come to find out we have been there numerous times in the past replacing contactors... so this makes sense. I believe it was 20ga wire installed in the unit before i changed it. This would explain why the coils were burning out.

[ryan1088]

Now you just have convince them to let you to fix it!