Installation Wiring Problem

[ChilledBeam]

Need some advice from you guys. I had an American Standard System installed last summer during an addition on our house so I was never really able to know if it ran and was installed properly.

Here's what I got:

• 4.0 Ton 16 Seer Two Stage Split A/C (R-410A), Model # 4A7A6048B1000A

• 90% Two Stage Variable Speed Gas Furnace 93mbtuh (21.0), Model # AUY100R9V4W

• Hi Eff Cased Evaporator Coil TXV-NB (21.0), Model # RXC054S3HPC

• 3H/2C Prog (7 Day) Gas-Elec-H/P w/Humidity Control, Model # ACONT803AS32D

• Outdoor Temp Sensor, Model # BAYSEN02AT

• AccuClean Whole House Air Cleaner (21.5), Model # AFD215ALAH000A

Now that's its getting hot I turned on the system for the 1st time this year and the furnace does not seem to come to high speed like it did when the unit was in heating mode. Additionally the pull down time is forever. House was 84F and I set the thermostat for 74F and it took over a day to pull it down.

I know my load calc was right and I have enough compressor and blower so I pulled the wiring diagrams and made notes of how the thermostat, furnace and condensing unit were wired and think I have found the problem.

Here is a diagram of how the system is wired and how its supposed to be wired:



I think its not wired right because:

• The BK terminal on the furnace should be wired to Y2 on the condensing unit and that's second stage of cooling.

• W2 from the stat is wired to Y on the furnace and that looks wrong.

• The BK jumper has not been cut.

• The R to O jumper has not been installed.

• Y from the stat is wired to YLO instead of Y.

• I have no idea what is going on at the condensing unit with all those wires tied together...

Can you guy help me confirm what is wrong so when I call the installer I can get him to correct it. They have already been out once and told me all wiring is correct but clearly I don't think so.

Thanks in advance!

ChilledBeam

[hvacgreg]

Yes you are correct it is wired wrong call the installer back and have them wire it like your second picture.

[sarpanch2001]

you got it

[ChilledBeam]

Should the W14 BK jumper be cut?

[hvacgreg]

yes

[HOT SHOT]

Now that's its getting hot I turned on the system for the 1st time this year and the furnace does not seem to come to high speed like it did when the unit was in heating mode.

Should the furnace blower be on high speed in heating mode? I thought it should only come on in cooling mode since cool air is harder to move. Are you sure you have enough CFM of air moving across the evaporator coil? You're losing efficiency somewhere, I can't fathom why the company who installed it is telling you it's wired correctly if it's not. But then again... any other problem with the install is their fault as well. Get it wired as the diagram shows and see if you've still got problems.

[Airmechanical]

wired wrong!



.

[ChilledBeam]

Its wired right now and working properly. The furnace is up to high speed and cooling the house correctly.

Its apparent the installer did not even look at the installation manual and had no familiarity with the two speed cooling and variable speed blower configuration. It amazes me that something so simple could be overlooked. I am not a service technician but all I had to do was pull the thermostat and furnace cover to see what was wrong...

The only thing I have left to do now is test the cooling stages via thermostat.

Thanks for your help.