DIY Home Improvement, Remodeling & Repair Forum > Appliances > HVAC > bad transformer?




Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 09-16-2012, 11:32 PM  
Rob-M
Junior Member
 
Join Date: Sep 2012
Posts: 1
Default

If you have a 110v at the furnace then you have 110v into transformer, which is called the primary, test the secondary side of transformer (24v) by followingthe leads from transformer going to the low voltage connections usually "R" & "C" or "X" thats the 24v connections. Depending on well who has worked on your furnace and the manufacturer there maybe be a fuse once the 24v leaves the transformer going to the low voltage/thermostat connections may be a inline car fuse or colored fuse. If you have 24v there than you will at stat. On a call for cooling your stat will send 24v to the AC unit normally the yellow wire or "y" connection. Your 2 low voltage wires at AC unit are the 24v, so check the voltage there. Then it can go thru safety switches, circuit board then the contactor so follow it. Theres also manual resets at the AC unit to high and low pressure you may try resetting them. Can go on and on but its a start to save u a buck. Make sure your meter is on AC volts and not DC volts too. Good Luck

Rob



__________________

[URL="http://www.AdvancedHVACService.com"]www.AdvancedHVACService.com[/URL]

Rob-M is offline  
 
Reply With Quote Quick reply to this message
Old 09-17-2012, 06:08 PM  
Wuzzat?
Senior Member
 
Wuzzat?'s Avatar
 
Join Date: Jan 2010
Posts: 2,227
Liked 150 Times on 137 Posts
Likes Given: 81

Default

Quote:
Originally Posted by randytrue View Post
OK, I'm getting 13V AC at the transformer output.
Can we assume the transformer is bad?

Randy
A partial short should be pretty difficult to trace down without cutting and jumpering some connections on your controller board.

Taking 40 VA as a generic rating for your transformer, the secondary current should be 40/24 = 1.7A or less. Check it if you can.
__________________
Wuzzat? is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Oil Burner Transformer jgilpin HVAC 12 03-07-2012 11:17 AM
Low voltage transformer? sdupp Electrical and Wiring 8 02-01-2012 05:28 AM
24vac transformer burns out paponertelo HVAC 24 05-31-2011 08:14 AM
switching transformer hum normal? mstar HVAC 3 12-18-2010 08:56 AM
Transformer crazy bbyyll General Home Improvement Discussion 2 08-01-2008 06:11 PM