Condensor Fan not turning on?

MPDano · 07-03-2012, 10:36 AM

Hello all! I am new here and this is my first post but I am not new to forums.

A couple days ago, I noticed that my home was not cooling down with the AC on (my home has central air/heat).

1) I have a small 220V light tester so I tested the fuses. I got a light on one side and not the other, so I switched the fuses and the light followed the fuse. I assumed the fuse was bad, so I replaced it at Home Depot.

Old Fuse# FLNR 35
New Fuse# FRN-R-35

I asked the Home Depot person if this mattered (different numbers) but they said as long as the amps is correct. Ok, bought it and went home and installed it. I still got nothing and the test light still follows the old good fuse and not the new one.

I am stumped and don't want to start buying parts just to try it.

2) Would a bad motor cause this condition? My Motor# is GE 5KCP39FGN809BS which is replaced with a Carrier# HC39GE237

3) I do have something in the system as I pushed the valve and there is pressure (so no leaks).

Any suggestions on what I should do next?

Doc Holliday · 07-03-2012, 11:02 AM

Is the compressor running while the fan is not? Did you check for voltage at the contactor in the condenser? 120 volts each leg to ground and 240 across both legs.

MPDano · 07-03-2012, 11:39 AM

Quote:

Originally Posted by Doc Holliday

Is the compressor running while the fan is not? Did you check for voltage at the contactor in the condenser? 120 volts each leg to ground and 240 across both legs.

Didn't think to check on each leg separately, I checked with the switch "off" at the box (next to Condensor, not Breaker Box) and got 220v at the posts "before" the fuse. I turned the switch at the Box "on" and got no voltage at the posts on the other end of the fuse.

biggles · 07-03-2012, 12:05 PM

shutting the condenser disconnect off should keep the contactor in so as you throw the cond/disconnect on with the fuses in and the contactor closed your blowing the one.shut the stat off inside no cooling then the contactor will drop out....outside.try local grainger on the fuses if they are local...HD guy might of been the paint aisle dude covering...should of told you the exact difference.keep the power off you need to RING out the compressor terminals to ground and the cond motor to ground and its body....digital ohm meter setting on that meter....burp the insulated freon line out there get oil on your fingers smell it if it burnt smell/stings your nose the compressor went...NUKE as in cooked,ground, boat anchor...

Blands · 07-03-2012, 01:43 PM

More than likely with the heat we have been seeing it is a capacitor. You may have one or two capacitors for your condensor and exaust fan, my system has one capacitor for both (5-35 micro @440 volts.). You should have a diagram on your panel. Either way caps are fairly cheap if you can deal directly with your local HVAC shop. Usually you will see a bloated dome on the shell of the cap and maybe even some leakage. If the caps have never been replaced, it would be a good step towards preventive maintanence anyways. As far as the fan motor, it should still be okay as long as it has not been continiously trying to start, this will overheat the motor and possibly damage the core or windings. Hope this helps.

MPDano · 07-03-2012, 05:16 PM

Yes, it has a single Cap in there. I have a local electrical place that carries stuff like this. I may remove it and bring it with me for comparison.

@biggles I did make sure the Thermostat was off inside when I turned it on by the cut off. What "contactor" are you referring to? What is the difference in the fuses as they look the same and I even saw an ebay ad stating the new one was a replacement or equivalent.

Thanks for all these great replies guys. It's giving me a lot of things to try.

biggles · 07-03-2012, 05:26 PM

inside the condenser the comp and fan are on one is it free and open as we call it then you push it in and it springs open all with out power....if it is welded closed the compressor shorted out the condenser fan motor willn't melt a contactor or weld it....did you or have a continuity tester to check all wires to the copper line or metal bodies

MPDano · 07-03-2012, 05:30 PM

Quote:

Originally Posted by biggles

inside the condenser the comp and fan are on one is it free and open as we call it then you push it in and it springs open all with out power....if it is welded closed the compressor shorted out the condenser fan motor willn't melt a contactor or weld it....did you or have a continuity tester to check all wires to the copper line or metal bodies

Ah, yes I did open the panel and see something that looked like contacts. I will make sure to power it off and see if i can get it to "un" contact.

Evstarr · 07-03-2012, 08:15 PM

Isn't the new fuse a rapid blow and the old a slow blow variety?

**beenthere** · 07-04-2012, 05:56 AM

Quote:

Originally Posted by Evstarr

Isn't the new fuse a rapid blow and the old a slow blow variety?

They're both time delay fuses.

MPDano · 07-05-2012, 11:23 AM

Hello,

Ok, verified that the contacts were not stuck. I had my wife turn on and off the thermostat from inside the house as I watched the contacts go on and off. I am assuming now that I have power and the fuse is fine. Cap looks good as well, at least no bulging you would expect. Here are some pics to show what I am dealing with:

MPDano · 07-05-2012, 01:49 PM

Quote:

Originally Posted by Blands

More than likely with the heat we have been seeing it is a capacitor. You may have one or two capacitors for your condensor and exaust fan, my system has one capacitor for both (5-35 micro @440 volts.). You should have a diagram on your panel. Either way caps are fairly cheap if you can deal directly with your local HVAC shop. Usually you will see a bloated dome on the shell of the cap and maybe even some leakage. If the caps have never been replaced, it would be a good step towards preventive maintanence anyways. As far as the fan motor, it should still be okay as long as it has not been continiously trying to start, this will overheat the motor and possibly damage the core or windings. Hope this helps.

As you say, I probably should just replace the Cap as part of Maintenance anyways. I know these things hold some charge, should I be safe to disconnect all the terminals on the Cap without issue? With power disconnected of course. Or maybe disconnect power for some period of time before messing with the Cap?

bob22 · 07-05-2012, 02:49 PM

Cut off breaker(s) and pull/turn off disconnect.
Check power leads to ground to ensure juice is off.
Make a diagram of where the leads go to before taking them off the capacitor.
Use the shaft of a screwdriver to short out the terminals to one another and to metal of unit; that should drain off any residual charge; then take off wires from cap.

MPDano · 07-05-2012, 03:11 PM

Quote:

Originally Posted by bob22

Cut off breaker(s) and pull/turn off disconnect.
Check power leads to ground to ensure juice is off.
Make a diagram of where the leads go to before taking them off the capacitor.
Use the shaft of a screwdriver to short out the terminals to one another and to metal of unit; that should drain off any residual charge; then take off wires from cap.

Excellent procedure! Thanks Bob!

If this doesn't work (Cap Replace), then what would you do for the next step in troubleshooting?

Marty S. · 07-05-2012, 06:35 PM

Might just be the picture angle but that capacitor sure looks like it has a little hump on top to me. Get a new one, they're around $15.

07-03-2012, 10:36 AM	#1
MPDano Newbie Join Date: Jul 2012 Posts: 8	Condensor Fan not turning on? Hello all! I am new here and this is my first post but I am not new to forums. A couple days ago, I noticed that my home was not cooling down with the AC on (my home has central air/heat). 1) I have a small 220V light tester so I tested the fuses. I got a light on one side and not the other, so I switched the fuses and the light followed the fuse. I assumed the fuse was bad, so I replaced it at Home Depot. Old Fuse# FLNR 35 New Fuse# FRN-R-35 I asked the Home Depot person if this mattered (different numbers) but they said as long as the amps is correct. Ok, bought it and went home and installed it. I still got nothing and the test light still follows the old good fuse and not the new one. I am stumped and don't want to start buying parts just to try it. 2) Would a bad motor cause this condition? My Motor# is GE 5KCP39FGN809BS which is replaced with a Carrier# HC39GE237 3) I do have something in the system as I pushed the valve and there is pressure (so no leaks). Any suggestions on what I should do next? Last edited by MPDano; 07-05-2012 at 08:36 PM.

07-03-2012, 11:02 AM	#2
Doc Holliday I'm Your Huckleberry Join Date: Mar 2011 Posts: 5,216	Condensor Fan not turning on? Is the compressor running while the fan is not? Did you check for voltage at the contactor in the condenser? 120 volts each leg to ground and 240 across both legs. __________________ Thanks.

07-03-2012, 12:05 PM	#4
biggles Member Join Date: Jan 2008 Location: Long Island Posts: 3,250	Condensor Fan not turning on? shutting the condenser disconnect off should keep the contactor in so as you throw the cond/disconnect on with the fuses in and the contactor closed your blowing the one.shut the stat off inside no cooling then the contactor will drop out....outside.try local grainger on the fuses if they are local...HD guy might of been the paint aisle dude covering...should of told you the exact difference.keep the power off you need to RING out the compressor terminals to ground and the cond motor to ground and its body....digital ohm meter setting on that meter....burp the insulated freon line out there get oil on your fingers smell it if it burnt smell/stings your nose the compressor went...NUKE as in cooked,ground, boat anchor...

07-03-2012, 01:43 PM	#5
Blands Newbie Join Date: Jul 2012 Posts: 1	Condensor Fan not turning on? More than likely with the heat we have been seeing it is a capacitor. You may have one or two capacitors for your condensor and exaust fan, my system has one capacitor for both (5-35 micro @440 volts.). You should have a diagram on your panel. Either way caps are fairly cheap if you can deal directly with your local HVAC shop. Usually you will see a bloated dome on the shell of the cap and maybe even some leakage. If the caps have never been replaced, it would be a good step towards preventive maintanence anyways. As far as the fan motor, it should still be okay as long as it has not been continiously trying to start, this will overheat the motor and possibly damage the core or windings. Hope this helps.

07-03-2012, 05:16 PM	#6
MPDano Newbie Join Date: Jul 2012 Posts: 8	Condensor Fan not turning on? Yes, it has a single Cap in there. I have a local electrical place that carries stuff like this. I may remove it and bring it with me for comparison. @biggles I did make sure the Thermostat was off inside when I turned it on by the cut off. What "contactor" are you referring to? What is the difference in the fuses as they look the same and I even saw an ebay ad stating the new one was a replacement or equivalent. Thanks for all these great replies guys. It's giving me a lot of things to try.

Condensor Fan not turning on?