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Discussion Starter #1
I have had three HVAC guys here and have only been able to get heat going. Spending lots of money and even purchasing a new outdoor AC unit/condenser which at this point I am convinced I did not need. So I decided to start digging and doing my own research.
I have a nordyne furnace model feh-012ha-04 that has its own transformer. I have a nordyne a-coil model aasa 030xb-02. I have a nordyne blower relay box model 901245. I have a nordyne heat/cool blower unit model 901282. I have a honeywell thermostat. The new outside unit is Ameristar 13 deer split system rotary compressor air conditioner 1.5-2.5 tons with R22.
So here are my questions:
1. How should the outdoor unit be wired to its own transformer and then the low voltages wires to the transformer for AC only.
2. How should the low voltage wire be conectect at the terminal on the AC blower relay?
Currently:
There are three low voltage thermostat wires to the outside unit, green, red and white. I will post a photo on how that is all wired currently to see if it is correct.
There are five low voltage thermostat wires to the theremostat, red (R for heat), Blue (Rc for cooling) no jumper, green to G at the thermostat, yellow to Y at the thermostat and white to W at the thermostat.
I will post a photo as to how everything is wired at the terminal on the AC blower relay box to see if this is also correct.

If there is any additional information or photos needed, please let me know.

Any advice is much appreciated. All the money I have spent I could have had a new system installed. I have been depleted of available funds. We have rocked window units all summer and do not want to run heaters all winter. I stated earlier that one HVAC tech was successful in getting the blower to kick on for the heat call but not the AC call. Since then another tech has jacked that all up.

I purchased and installed a new relay per the wiring diagram for the AC blower relay box.
I have also purchased a new transformer for the outdoor unit but haveno clue if it is installed correctly because the HVAC tech who sold me a new one took the old one.
 

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That air handler is very old.

Not sure why you're getting the outdoor suction replaced. You're pretty much dealing with clowns if they replace the outdoor unit because it doesn't turn on without identifying what's wrong.

Yah, if it's not working, call them back -> you shouldn't have to fix this yourself.

Really, re-using an old coil is a mistake. So is going with R22 - it's being phased out and repairs will be very costly.

The old coil can leak.

It's the wrong size for the new unit because the efficiency standards have changed.

The coil has a restrictor (call a metering device) that has to match the spec of the new unit -> some contractors may not change it, leading to really poor performance.

The operating pressure of the new unit is different so your old coil's metering device won't allow enough refrigerant to flow into the coil.

All in all, you should request that they make it work and also request that the coil and metering device are changed to match the new outdoor unit.

A new coil may not fit into that air handler, necessitating replacement.
 

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Discussion Starter #5
This is kinda confusing. The company that installed it can't get the AC to work?
Nope. Said they needed the wiring diagram. I know that having three different techs out has probably caused some issues because of each one not knowing what the other did. When the outside unit was replaced it all worked for a few hours, but something went wrong, I believe he tried to wire it all up on one transformer which could not hold the load. This is the reason I have asked if the outdoor unit has been wired properly to the transformer within the unit. Here is a photo of it. All the wiring has been reverted back to the way it was designed to be per the schematics on the individual parts. I just don't have anything to compare the outside unit too.
 

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Discussion Starter #6
That air handler is very old.
Yes, it is very old. So old that the company does not have any of the information (installation instructions, wiring diagrams, or manuals) for any of the parts.

I have followed all of the wiring per the schematics on each individual part but do not have anything to compare the outdoor unit to. I installed the new transformer to the condenser but want to be sure it is wired properly.

The furnace runs in one transformer and the AC in its own.
 

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presumably it worked before and was wired right.

the wiring shouldn't be different with a new condenser.

it sounds like in trying to run it off of one transformer, it was overloaded and failed or the fuse on the low voltage circuit blew.

The transformer in the air handler was probably for heat only, not having a high enough volt-amp rating for a/c.

If this is the case, the next step would be to rectify that and re-wire the low voltage circuits so cooling runs off of the fan centre's transformer again.

This is impossible to deal with over the net and you need a competent technician to straighten this all out.

If you have the funds, the best option at this point may be to put in a matching air handler and coil with the transformer and relays for cooling built in.

You aren't dealing with the highest quality people at least based on your posts.

Matching a new 13 seer unit to a very old coil in itself is a horrible idea.

Now they can't get it to run? residential control circuits aren't overly complex.

The brand is a chinese one -> nothing necessarily wrong with the unit itself but rather that the contractor is more interested in cutting costs than anything else.

What prompted the replacement in the first place?
 
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user is right, these guys are pathetic. Wiring diagram should be on the inside of the cover. A good tech could figure that out without a diagram. Who installed the transformer in the condensing unit?
 

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Discussion Starter #9
presumably it worked before and was wired right.

the wiring shouldn't be different with a new condenser.

it sounds like in trying to run it off of one transformer, it was overloaded and failed or the fuse on the low voltage circuit blew.

The transformer in the air handler was probably for heat only, not having a high enough volt-amp rating for a/c.

If this is the case, the next step would be to rectify that and re-wire the low voltage circuits so cooling runs off of the fan centre's transformer again.

This is impossible to deal with over the net and you need a competent technician to straighten this all out.

If you have the funds, the best option at this point may be to put in a matching air handler and coil with the transformer and relays for cooling built in.

You aren't dealing with the highest quality people at least based on your posts.

Matching a new 13 seer unit to a very old coil in itself is a horrible idea.

Now they can't get it to run? residential control circuits aren't overly complex.

The brand is a chinese one -> nothing necessarily wrong with the unit itself but rather that the contractor is more interested in cutting costs than anything else.

What prompted the replacement in the first place?
When the new condenser was added a transformer was not put in and yes it was all wired to one transformer which I also assume overloaded and stopped working.

I have corrected all of the wiring per the diagrams but have nothing to compare the outdoor unit wiring to in order to make sure the transformer has been wired in properly.

Not sure why the outdoor unit was replaced other than a tech telling me I needed to. This all started when an unnamed person in my household decided to put in a new thermostat. I believe the jumper was left in and the two circuits were crossed causing the transforms to blow as well as the relay.

I got a new relay as well. Prior to switching all of the wiring back to the diagrams the blower would kick on when calling for heat but not cooling. The HVAC could not get 24 from the condenser to the airhandler but he also did not have a transformer in there.
The blower relay box says the system has been wired for a two transformer system. I told them that over the phone when I called them back to say it wasn't working. The replays was that must be the problem so I am going to need your wiring diagram. The only thing I have is what is on the units individual pieces.
 

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The condensing unit does not need a transformer. I would remove the transformer and see what size it is, should say something like 40 VA. Let us know.

Did you check the fuse on the inside transformer?
 

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Discussion Starter #11
user is right, these guys are pathetic. Wiring diagram should be on the inside of the cover. A good tech could figure that out without a diagram. Who installed the transformer in the condensing unit?
I did. I don't know if it's correct. I figured someone could tell me by looking at the photos of the theremostat wires on the the airhandler terminals and the diagram of the airhandler. Just to check the inside connections.
 

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Discussion Starter #13
The condensing unit does not need a transformer. I would remove the transformer and see what size it is, should say something like 40 VA. Let us know.

Did you check the fuse on the inside transformer?
Why does it not need its own transformer if that is the way the blower relay box is wired? Please see the photos below. 1st picture is inside the blower relay box. Second picture is of the diagram on the front of the blower relay box and the third picture is a close up of the instructions on the relay box and the fourth photo is from the diagram on the furnace referring to the the relay box that is installed.
 

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Discussion Starter #14
The condensing unit does not need a transformer. I would remove the transformer and see what size it is, should say something like 40 VA. Let us know.

Did you check the fuse on the inside transformer?
Which transformer would you like for me to check?
Fuses are fine.
 

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Discussion Starter #15
The condensing unit does not need a transformer. I would remove the transformer and see what size it is, should say something like 40 VA. Let us know.

Did you check the fuse on the inside transformer?
The transformer on the AC unit is 40va
The old transformer that was on the furnace was also 40va. This has since been replaced with one that is 90-T40F3. The bigger transformer was installed by the tech who was unable to get the 24volts at the airhandler.
 

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Discussion Starter #19
The transformer only has 1 fuse, its purple with a red and yellow wires going to it.
The purple fuse is intact.
For thirteen plus years everything worked perfectly. There was always one transformer in the furnace section and one on the condenser.
 
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