Air Handling Fan not running


  #1  
Old 05-28-08, 10:50 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Air Handling Fan not running

A/C Air Handling Fan not running with A/C compressor and condenser fan running.
Tried Heat, Fan does not run.
Turned Fan to ON at thermostat, No Fan.
Checked Voltage across capacitor with Fan switched to "on" at thermostat
Zero Volts ac.
Is this the circuit board ?
Or do I have to remove the Fan and check out of the unit ?
thanks Ian
Added:-
Carrier HSC4060 A/C
58RAV-11520 series 160 Heater unit.
 

Last edited by IanHen; 05-28-08 at 11:23 AM. Reason: added detail
  #2  
Old 05-28-08, 11:31 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 976
Upvotes: 0
Received 0 Upvotes on 0 Posts
Checking for voltage across the capacitor terminals is not how you test the motor. Here's what you do:

This motor has 2 brown capacitor wires plus the following: Black, Yellow, Blue, Red and White (so, is a 4-speed motor).

In cooling mode, Black and White are the ones getting juice.
With the thermostat calling for cooling, check the voltage across Blk and Whi (you can do this at the board, the terminals there are labeled: COOL and COM). If you get 120V there and the motor is not running, the motor "or" its capacitor are bad. Is the motor at least humming? Do you know how to test a capacitor?
 
  #3  
Old 05-28-08, 11:43 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by pflor
Checking for voltage across the capacitor terminals is not how you test the motor. Here's what you do:

This motor has 2 brown capacitor wires plus the following: Black, Yellow, Blue, Red and White (so, is a 4-speed motor).

In cooling mode, Black and White are the ones getting juice.
With the thermostat calling for cooling, check the voltage across Blk and Whi (you can do this at the board, the terminals there are labeled: COOL and COM). If you get 120V there and the motor is not running, the motor "or" its capacitor are bad. Is the motor at least humming? Do you know how to test a capacitor?
Thanks for a fast reply
No there is no humming.
Ok I will check it tonight.
If the thermostat calls for cooling the compressor runs, is this OK with the Fan off ?
I have a multimeter and can check the capacitor for shorts. I don't think i have a capacitance meter.
I also have a clamp type meter, this should measure 120V AC have not used it yet. (brought it to measure current draw)

BTW: I looked at the circuit diagram and concluded that at any speed there should be voltage across the capacitor.
 
  #4  
Old 05-29-08, 06:42 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
ok I turned it back on, had "wait" on thermostat.
Then Compressor turned on
Measured 0.0V black to white.
 
  #5  
Old 05-29-08, 07:22 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 976
Upvotes: 0
Received 0 Upvotes on 0 Posts
Make sure the board's LED is lit continuously (and not flashing). A continuous lit-up condition tells us that the board is getting its juice. Flashing tells us of some trouble there.

One more test before condemning the board (which is likely bad):
Disconnect those black and white blower wires from the points at the board where they are connected. With an x-cord feed 120V directly to the black (hot) and white (neutral) wires. If the motor now runs, then the board is not sending the much needed 120V signal to the motor.

You can also use this board's own self-diagnostic test feature:
Next to the LED there is a terminal labeled "TEST" and another labeled "C" (Com 24V). Locate them.
Shut OFF the room thermostat or disconnect the "R" thermostat lead (at the board). Briefly short the "TEST" terminal to the "C" terminal. Status LED will flash code and then turn on the inducer motor, hot surface igniter, blower motor-heat speed, and blower motor-cool speed for 10-15 seconds each.
I would expect you to see the inducer and igniter doing their thing, but not the blower.
 
  #6  
Old 05-29-08, 08:39 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
I am at work now so cant try this till I get home and it very hot here now over 90F (Dallas)
So I already ran the heat, the igniter worked and the furnace fired up but no Blower motor.
Yes light is on continuously, and i checked the 24 V at the thermostat wiring block, forget which one read 24V ( actually got 26V)
I am obviously keen to order the board if its bad.
 
  #7  
Old 05-29-08, 10:01 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 976
Upvotes: 0
Received 0 Upvotes on 0 Posts
Order a new board, it sure appears is bad, and even if it is not, is good to have a spare handy (you never know when you'll need it).

Juice up the black and white on the motor after you get home...if this gets the fan running, flip the t-stat to cooling and it will get the outdoor unit going. In thi manner you'll get your cooling until the new board comes.
(don't forget to have the blower door back in place, else you won't have return airflow in the house).

Totaline is the official Carrier parts distributor. You may want to contact them. have the full M/N of your furnace handy (maybe the s/n too) and tell them is the control board what you need.

http://www.totaline.com/
 
  #8  
Old 05-29-08, 11:16 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by pflor
Order a new board, it sure appears is bad, and even if it is not, is good to have a spare handy (you never know when you'll need it).

Juice up the black and white on the motor after you get home...if this gets the fan running, flip the t-stat to cooling and it will get the outdoor unit going. In thi manner you'll get your cooling until the new board comes.
(don't forget to have the blower door back in place, else you won't have return airflow in the house).

Totaline is the official Carrier parts distributor. You may want to contact them. have the full M/N of your furnace handy (maybe the s/n too) and tell them is the control board what you need.

http://www.totaline.com/
Good idea, that will test the motor and get it running as well !!!
 
  #9  
Old 05-30-08, 11:08 AM
M
Member
Join Date: May 2008
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Totaline

Originally Posted by pflor
Totaline is the official Carrier parts distributor. You may want to contact them. have the full M/N of your furnace handy (maybe the s/n too) and tell them is the control board what you need.

http://www.totaline.com/
According to the web site, they only sell to dealers. Can a homeowner buy parts from them?
 
  #10  
Old 05-30-08, 11:55 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by Mooneymite
According to the web site, they only sell to dealers. Can a homeowner buy parts from them?
I ordered a made in usa replacement from a dealer on ebay, buy it now, no auction stuff....
 
  #11  
Old 06-02-08, 09:08 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Fan works fine when connected directly to 110V
Since board did not show an error i suspect its just the on board relay. new board is coming .....
 
  #12  
Old 06-24-08, 07:07 AM
I
Member
Thread Starter
Join Date: Apr 2008
Location: Richardson Texas
Posts: 16
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by IanHen
Fan works fine when connected directly to 110V
Since board did not show an error i suspect its just the on board relay. new board is coming .....
Well I am tardy in giving an update.
First, thanks for the help.
The new board worked fine, only issue was the 110V power in lead was too short (this was a replacement board not OEM, more on that in a min.)
The old board was burnt at the relay pin. clearly this was the problem, and the board is probably repairable.
Interestingly the replacement board, made in USA, has relays that have terminals on them so the Fan power doesn't go through the board. Much better design IMHO.
 
  #13  
Old 06-24-08, 08:53 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 976
Upvotes: 0
Received 0 Upvotes on 0 Posts
Glad to read that things worked out well for you.
Stay cool
 
 

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