With the triple digits 100-115 temps out here in Oklahoma I've found the upstairs A/C cannot keep up with the heat. Herein lies problem as I see it. I think the blower motor is wired incorrectly. In the winter the air blowing out of the registers are far greater than in the summer. Its just a trickle in the summer. Not enough air is moving to adequately cool the upstairs. My downstairs unit, (separate A/C heating unit- top from bottom) blows a great amount of air. Filters have been cleaned, same goes for condensers fins outside-All cleaned.
Below are photos.
Here is what I have:
Three wires coming in and five wires coming out of the Blower motor. Here is how it's connected, also see pics below.
Three wires / Five wires (blower motor)
Red ------- Blue
Black ------ Black
White ----- White
____ ------ Red Capped
____ ------ Green connected to housing
On the blower motor is a label showing the wiring diagram.
Another label is found on the shroud or blower motor housing.
The 2nd photo shows how it is connected.
My question:
Does this connection confirm the blower motor is connected improperly, esp for summer use? In other words, as connected is this why in the summer the A/C air discharge is so light? Naturally, if it is incorrectly connected how do I then correct it?
Looking fwd to your help?
TIA,
Ron
Last edited by HVACMac; 08-13-2011 at 04:24 PM.
Reason: image probs
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cap the blue(that was connected to that power in red) and connect the 2 reds together RED is LOW for Heat............ Black is HI for cooling.now to see if the fan runs in hi speed shut the stat and only switch the FAN to ON should have the hi fan blowing...if not the heat and cool fan relays wires(Black/RED) within the furnace are backwards..you can't check LO fan with the heat from the stat because it cycles thru a time delayon that board in the furnace in the heating season not like the stat as FAN/ON from the subbase...lets hear back
High speed on colling model
Med high speed or Med speed to heating mode
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**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
if not the heat and cool fan relays wires(Black/RED) within the furnace are backwards..you can't check LO fan with the heat from the stat because it cycles thru a time delayon that board in the furnace in the heating season not like the stat as FAN/ON from the subbase...lets hear back
The pic posted shows two relays. I see a transformer, next to it is a small brown relay and above it to the right is a large aluminum Honeywell relay? Your thoughts? http://imgs.inkfrog.com/pix/msmikee/relays.jpg
Black wire should be connected in high speed on control board. Check also if A-coil is clean. Filter is clean.
Could be low on refrigerant. But you need hook up the gauges to check this
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**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
Black wire should be connected in high speed on control board. Check also if A-coil is clean. Filter is clean.
Could be low on refrigerant. But you need hook up the gauges to check this
Forgot to say, Freon is fine. All filters are clean. A-Coil has been is cleaned. As to "black wire to control board" thats a big unknown to me, Have no idea where to even look.
Ron
Last edited by HVACMac; 08-13-2011 at 04:24 PM.
Reason: image prob
To make sure your AC is running ok, you need to get the temp at the return and just after the a-coil. If the temp difference is under 15 you have some problem. If not, It's insulation problem.
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**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
To make sure your AC is running ok, you need to get the temp at the return and just after the a-coil. If the temp difference is under 15 you have some problem. If not, It's insulation problem.
Hey Jj, thx. I think that is way beyound my limited expertise. A month or so ago a HVAC man did check the freon levels and found them to be fine. He check temps using his gauges. But, not sure what he was referencing. Ron
I'm in Texas. I know it's hard to keep inside the house cold when outdoor temp is 105-110. I think your AC is running ok. You have to leave your AC running all night to remove all the heat.
__________________
**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
I hear that! TX was nearly as hot as us.
The downstairs unit really can keep the first floor cold AND it really can blow air. While upstairs the A/C has to contend with the attic heat and the evaporator/Furnace/ducts are all in the attic too! So its hot all around. Not surprised its struggling with 105+ degrees. Worse, temps are even hotter in the attic.
But, what concerns me, is the low volume of air coming out of the registers. Doesn't make sense to me and is why Im posting hoping to find an answer or least some direction before I call the A/C man. Ron
Assuming that AC is okay. It's just a sensation that air is not flowing properly during hot days. I bet this ends during normal days. This is the same thing when AC is low of refrigerant.
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**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
Exactly. Where Iam stumped is the volume of air I am NOT getting as compared to downstairs. Downstairs air rushes out from every register with great volume. Upstairs is only a whisper. I' am wondering maybe a faster RPM motor is needed?
What I am trying to say that your problem is not AC. The problem is more serious, insulation, load calculation, ducts calculation.
The blower motor is already setup in high speed in cooling mode ( motor black wire )
__________________
**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.
you can't check LO fan with the heat from the stat because it cycles thru a time delayon that board in the furnace in the heating season not like the stat as FAN/ON from the subbase...lets hear back
Linear Mode
