Customer Support 7 days a week

Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

New Topic Post Reply
Options
Go to last post Go to first unread
BobRegal  
#1 Posted : Wednesday, July 11, 2012 9:56:39 AM(UTC)
Quote
BobRegal

Rank: Member

Groups: Registered
Joined: 7/31/2010(UTC)
Posts: 5

OK.. I got a call from my mother that her AC isn't cooling off the house. I have no errors on the furnace. The furnace appears to be wired properly, as well as the thermostat. What I am seeing, and what the diagrams read, When the furnace is heating the house, the relay sends the current to the blue wire, Medium/Low fan speed, and when Cooling, to the black wire for high speed. The furnace fan is only spinning one speed.. and I am assuming it's medium/low...
From the diagram... I don't understand how the speed control of the fan happens. The SPDT relay sends the voltage to the blue wire, hence medium/low speed... and when cooling, the voltage is sent to the black wire, hence High speed.
My question:
Is the speed control in the motor? Blue wire medium/low and Black wire High... or is it in the relay... partial voltage to the blue wire, then the relay adds voltage to the black wire, sending voltage to both the black and blue wires for high speed?





UserPostedImage
UserPostedImage
UserPostedImageUserPostedImage
Sponsor
See inside of your appliance - diagrams and part photos for virtually every model.

powered by AppliancePartsPros.com
 
Simon / APP Team  
#2 Posted: : Wednesday, July 11, 2012 2:04:58 PM(UTC)
Quote
Simon / APP Team

Rank: Advanced Member

Groups: APP Team
Joined: 2/12/2012(UTC)
Posts: 5,556

Hi.

While the AC is running pull the black wire off the control board (be very careful not to brake or short anything). If the blower stops - it's OK.

There are other things to check: first of all the freon pressure, the air filter. If you don't have the gauges touch the thick copper pipe - must be sweating and dripping condensation. If it's not - there is the sealed system problem.

When testing keep the FAU closed.

Thank you.

Simon.
BobRegal  
#3 Posted : Sunday, July 15, 2012 2:57:27 PM(UTC)
Quote
BobRegal

Rank: Member

Groups: Registered
Joined: 7/31/2010(UTC)
Posts: 5

When I took off the inspection cover, the copper coils on the ends had condensation, but nothing on the fins at all... Maybe it needs a shot of freon... guess I will have her call for a check-up.
Thanks!

Originally Posted by: Simon / APP Team Go to Quoted Post
Hi.

While the AC is running pull the black wire off the control board (be very careful not to brake or short anything). If the blower stops - it's OK.

There are other things to check: first of all the freon pressure, the air filter. If you don't have the gauges touch the thick copper pipe - must be sweating and dripping condensation. If it's not - there is the sealed system problem.

When testing keep the FAU closed.

Thank you.

Simon.
Simon / APP Team  
#4 Posted : Monday, July 16, 2012 9:31:32 AM(UTC)
Quote
Simon / APP Team

Rank: Advanced Member

Groups: APP Team
Joined: 2/12/2012(UTC)
Posts: 5,556

You are welcome.

Simon.
Quick Reply Show Quick Reply
Users browsing this topic
New Topic Post Reply
Forum Jump  
You can post new topics in this forum.
You can reply to topics in this forum.
You can delete your posts in this forum.
You can edit your posts in this forum.
You cannot create polls in this forum.
You can vote in polls in this forum.