coleman 3400-815

[wyndsurfr]

First off this is a coleman 3400-815 heat and ac...

I have fixed my 3400-800 unit (heat only) before and was very confident going over to help my friend on his, well not so confident now...

I'm sure it's got a bad sequencer which was the start of all the issues, but in diagnosing the problem I burnt up his motor (fire) whoops... Good news was I had another universal fit blower here at home, we put it in and it works great, well not really great...

here's the problems.

1. the motor seems to be getting hotter than it should, I am running the motor off of the orange common, and the yellow (medium-low) wire. It seems like it's getting hot, not sure how hot these motors run, but after we pull the disconnect plug the heat starts to seep out of the motor body and after a little bit it is very very hot, not causing physical damage but hot enough to make you move your hand pretty quick. What could be the problem there? After setting one motor on fire we haven't run it very long at a time at all, 45 seconds to 1 minute tops.

2. The 3 amp fuse going to the transformer keeps blowing when we tell the thermostat to ask for heat. He replaced the thermostat today before I got there, everything went fine according to instructions on thermostat except for we weren't sure if RH and RC should have stayed jumped or not, he pulled the jumper out at the thermostat itself, there was no place for a black X2 labeled wire but it terminated into nothing inside the furnace so we figured it did not matter.

(2) I did searching on here and found a post saying to pull the low voltage wires, then put them on 1 at a time to see if there is a short and where it is at. His cooling system has a 120 breaker for it, when the disconnect is in place on the furnace it throws the breaker in his main panel for the cooling system.

3. there is another part in there that I don't know what it's called, it sits beneath the transformer and to the right of the sequencer, it almost looks like a sequencer but on the back of it are windings like a transformer would have, the wires in number 2 and number 5 position came off inadvertently and we weren't sure if we put them back on correctly, I put blue on five and red on 2. Could this be causing our problems? (the blue was running along with the yellow going to his old fan motor now blue isn't hooked up to anything)

Thanks for running this site guys, yall rock, I see how much you help dummies like us and you've got some good karma heading your way for a long time to come...

[Robert]

Hi,

The number one rule when trying hvac diy repairs is knowing your limitations and when to stop.

That time has arrived and it is best to call an hvac tech at this point.

Here is what I and you know:

1-There has been a fire and one motor burnt up
2- There was an electrical component problem to begin with
3- You have a low voltage fuse continuously blowing
4- You have a line/main voltage breaker tripping
5- A second motor is getting very hot and quickly becoming another # 1.
6- You are unsure what to do next
7- I'm not there physically there to see what has happened


With 30+ years in this trade, I can say with confidence that you are best served here to call an hvac tech out.

Could be electrical shorts on both low and high voltage sides of circuits, bad components, wrong motor, fire damage, wire damage from heat, over amperage problems to name a few.

Those are problems that need to be correctly diagnosed before placing that unit back on line for the safety of your friend and you and any family living there.

Too many variables for me to safely attempt any type suggestions from here.


Take care and best wishes,
Robert

[wyndsurfr]

sounds like a plan for me then. This thing has definitely got shorts someplace, I don't think the shorts are before the furnace itself, but it is definitely a mess. thanks robert, that was the conclusion we came to yesterday provided I could not find a good wiring schematic on the internet, I found no schematic, so we don't know where we are at.

I appreciate the advice, thanks for your time.

[Robert]

Hi,
'
You're very welcome, happy to help.


Thanks,
Robert