Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 08-02-2011, 08:20 PM   #1
Newbie
 
Join Date: Aug 2011
Location: Virginia
Posts: 3
Share |
Default

Condenser problems


Hello all,

Looking for a bit of insight if possible. Got a call from the wife today saying the ac was no longer blowing cold air, but "cool". Got home from work and she was right. The air was blowing but was cool at best...like just the air handler was delivering air.

I went outside to the condenser and heard the fan humming....like a locked rotor hum. I took a screwdriver and just bumped it and came on and started spinning freely, like there was no resistance at all....realized the hum was probably from it just not quite being able to turn. Still no cold air though This is where it gets interesting...

This is what I did:

Checked fuses and they were good.
Pushed in contactor and checked continuity between line and load side.
Checked continuity between both 120v legs on load side of contactor and there was...only problem being I have a cheap meter which wont tell me ohms, only that there IS continuity.

My question is.....what is this typical of? I am somewhat handy and think that I could replace the capacitor on my own. Unfortunately I dont own or have access to an analog meter to try to bleed the voltage off. Or does this sound like a bad compressor?

This wasn't a gradual thing. I went to bed last night with cold air, no hum, fan running fine. I'm guessing the humming fan has is a symptom but not a cause right?

Any help would be much appreciated. If it's best just to call a tech out I will do that and don't mind. The unit is not under warranty and if I have to pay for a no compressor so be it, but if it is something simple that looks and smells like it, I would like to give it a shot.

Thanks again to all.

VAlegacy is offline   Reply With Quote
Old 08-02-2011, 08:49 PM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,371
Default

Condenser problems


Probably a bad/weak capacitor. Leave the power turned off over night. In the morning short across the terminals with a screw driver or needle nose pliers(insulated handles). Mark what wires are connected whee, and the disconnect them and remove capacitor, and go get another one of the same valus, and install it.

beenthere is offline   Reply With Quote
Old 08-02-2011, 09:05 PM   #3
Newbie
 
Join Date: Aug 2011
Location: Virginia
Posts: 3
Default

Condenser problems


So I checked rotation on the fan.....and it was spinning incorrect. I knew this because there was a rotation arrow on the fan. The weird thing is I had the wife go inside and turn on the condenser from the thermostat...the fan didn't move, but I tapped it with a screwdriver I could make it turn on and start spinning either direction, and stay spinning. Then the fan just shut off altogether. Still sound like a bad capacitor?

Last edited by VAlegacy; 08-02-2011 at 09:11 PM.
VAlegacy is offline   Reply With Quote
Old 08-02-2011, 09:13 PM   #4
Member
 
Join Date: May 2010
Location: San Antonio
Posts: 375
Default

Condenser problems


look at the capacitor, it's probably bulged on the top (should be flat) meaning it's definitely bad. if you have a multimeter with capacitance you can measure it if you can't tell visibly that it's bad.
NitroNate is offline   Reply With Quote
Old 08-03-2011, 02:53 AM   #5
REP
Member
 
Join Date: Jul 2011
Posts: 615
Default

Condenser problems


The capcitor is the cheapest thing on the unit I believe.It doesn't have to be bloated to be bad.Label your wires and replace .You must replace with exact same uf values.If it says 370 volt you can go up to 440 volt but not the other way around.
There is a small chance that the motor windins have been damaged but I'd really be surprised if they were.
In the mean time do not run the unit.
REP is offline   Reply With Quote
Old 08-03-2011, 03:47 PM   #6
Member
 
Join Date: Sep 2010
Posts: 449
Default

Condenser problems


REP is right. Wikipedia states that after PCBs were banned, caps are not as reliable. They are better for the environment however. A weak link in every system for sure. First thing to check in a failure.

A neighbor's cap went last week but it was obvious. Top blew off completely and inside material looked like gray paste. To make a safe condition while we replaced, we disconnected unit outside by pulling a jumper from a wall mounted box. It was not a switch, just a jumper. Each side of copper terminal was a little corroded so we wirebrushed a bit, to ensure good contact.

My unit is very different and significantly older. I have the red, black and white heavy wiring going to a fully functioning outdoor circuit breaker (green too for grounding) mounted on garage. The white goes to the neutral bar, the red and black each to a breaker switch that are joined and can only be thrown at the same time. When my outside unit stopped recently, the main breaker did not trip nor did the outdoor breaker. The unit's red and black supply wires hook to screws at bottom of each breaker. I noticed the black and white wires in box were close together and were shorting out. The plastic coat of the black wire at the end, as it entered the breaker, was very brittle and crumbled when touched. This means corrosion and high resistance. I was able to trim black wire enough to get a better connection to its breaker and unit runs normally. I will perform a complete inspection at end of season and replace parts as necessary, probably the breaker switches. So,...testing for 220 across pressure switch would have saved me some time.
diyorpay is offline   Reply With Quote
Old 08-03-2011, 07:17 PM   #7
Newbie
 
Join Date: Aug 2011
Location: Virginia
Posts: 3
Default

Condenser problems


Just a quick thank you to those who responded to my thread. The capacitor was bad. A 15 min trip to the supply shop and 5 min install and is running great. Thanks again guys.

VAlegacy is offline   Reply With Quote
Reply


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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Carrier Condenser Unit Screwed? gimmes name HVAC 6 07-24-2011 07:05 AM
New Rheem Condenser RPQL-024JEZ Problems gxsalas HVAC 13 07-21-2011 07:50 PM
Goodman Fan Condenser Replacement Help bigjohnstud4200 HVAC 2 07-03-2010 01:54 PM
Residential AC Unit - Can a stalled condenser fan cause other problems? bcphoto HVAC 6 04-03-2010 10:09 AM
Condenser Fan Quits After approx 10 min kdogg HVAC 5 08-06-2008 06:03 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.