Much delayed start of compressor and fan


  #1  
Old 04-22-09, 05:01 PM
J
Member
Thread Starter
Join Date: Apr 2009
Location: California
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Much delayed start of compressor and fan

With the thermostat calling for cooling at the start of the day, the compressor and condenser fan of my Rheem central air unit do not start to run until about 2:00PM when the outdoor unit is partially under the sun. When the thermostat opens and then calls for cooling again, the contactor would pull in but the compressor and fan would not kick in until about 20 to 30 minutes later. Does anyone have any idea where the problem is?
 
  #2  
Old 04-23-09, 03:09 PM
E
Banned. Rule And/Or Policy Violation
Join Date: May 2007
Location: Wisconsin
Posts: 7,826
Upvotes: 0
Received 1 Upvote on 1 Post
Do you have a voltmeter to verify that even though contactor closes, that voltage is going through it to those 2 components?
 
  #3  
Old 04-25-09, 05:42 PM
HVAC Mech.'s Avatar
Member
Join Date: Jun 2008
Location: Rocky Hill, CT. USA
Posts: 220
Upvotes: 0
Received 0 Upvotes on 0 Posts
It could be a dozen different things, or combined faults. A few I would check: Supply voltage withing 10% of name plate, condition of contactor points, maybe marginal compressor capacitor, compressor on it's way out - mechanically. Bad time delay or board too if that's where it's mounted. Bad programmable Tstat.
This type of job would entail sifting through the possibilities logically and knowing what should be, when operating normally.
Tom Beer 4U2
 
  #4  
Old 05-05-09, 11:54 AM
J
Member
Thread Starter
Join Date: Apr 2009
Location: California
Posts: 2
Upvotes: 0
Received 0 Upvotes on 0 Posts
Much delayed start of compressor and fan

Thank you for your replies. I did as you two suggested. With the thermostat calling for cooling, voltage input to the DELAY ON BREAK TIMER IS 24 VOLTS. However across the output terminals leading to the 24V coil of the contactor, voltage is zero. I took the measurement about 2 minutes after switching the thermostat to cool. The delay timer is EAC-426/4-030 which according to the literature is a 30-second delay. Do you agree that the problem lies in a defective Delay Timer?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: