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 05-07-2012, 02:40 PM   #1
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Share |
Default

Wires on Fire


AC condensor unit started with a reversed bent blade cooling fan. Vibrations loosened power cable, wires grounded and burned up Replaced wire harness, wires burned up Wires also transferred heat to the local breaker, it burned up Changed all components, in this case, start relay(carbonized contacts), all caps including "hard start" and "bonus" cap for the fan not in the schematic. System failed, breaker inside overheated and burned open Replaced it. Cooling fan got tight, system failed. And for those who helped brilliantly with the 4m205j thread, I swapped parts out of that unit to troubleshoot this one. So..
1. The fan motor that failed had bushing not bearing, lubricated with "oily sawdust" should I just change it?
2. Reversed cooling fan, any more expected problems?
3. Hard start caps, are they ok or a "band-aid"?
4. My breakers are rated for ambient 40C, 104F, in Houston area this is a cool summer day, is it normal to use these?
5. I have slim line GE breakers inside panel, it seems if changed to the wider body breaker it should be able to dissapate more heat?

jb64 is offline   Reply With Quote
Old 05-07-2012, 03:12 PM   #2
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,556
Default

Wires on Fire


Are you being sarcastic with your use of the term "brilliantly helped"? I can't tell nor could I tell last time with your last post what it is you're wanting. If you need(ed) help with wiring than ask in a manner we can all understand. Pics always help as well.

And I just can't help but say that this is a perfect example of why certain things are best left to the professional AND I can't help but say I told you so for running the system without refrigerant. I'd be willing to bet you're compressor is fried as well. Something was terribley wrong with the wiring for this to occur, phase to phase or something.

I don't kow what to tell you any longer, obvously you jumped the gun. Next time it may be your entire home that burns. Might be time to call out that professional I was talking about.

__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 05-07-2012, 03:49 PM   #3
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,556
Default

Wires on Fire


Btw, there is not such a thing as a "bonus" cap for the fan. Compressor's have hard start kits to assist in their starting as they have refrigerant equaliziation issues to overcome. There is no air equalization issues that a fan motor needs to fight. If there were a "bonus" fan cap I'd have heard of it by now in my 12 years in this trade. Someone can correct me if I'm wrong.


Hard start kits can amplify electrical current by up to 600% for the compressor alone. Your normal caps only do it to about 3 times the normal voltage.


I don't know what you did but you royally screwed up. Do you have any idea how hot a normally well lubed compressor becomes on start up? What happens to a car without any oil in it? The motor seizes and many catch on fire in the process.



You had mutliple concerns that needed to be addressed and you ignored them and now you're paying the hefty price. I certainly hope you don't go about attempting to run new circuits/wiring or messing with the elecrical service panel where the breakers are. I'd also be willing to bet your wiring to the unit is fried, got way too hot. All wiring is only rated to a certain temperature and once that temp is reached or breached the wire and the insulation are never the same, not trustworthy. It could start a fire even once everything is wired in properly.and assumed running well.


This work is far outside of your realm of comprehension. Be smart, be safe, call the pro's.


Good luck.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 05-07-2012, 03:50 PM   #4
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


Doc,
Please slow down. NO sarcasism. Looking for friends, not enemies. The second unit has been running ok mid last since summer. I was trying to be humorus on this post. Maybe, I am the local professional.
jb64 is offline   Reply With Quote
Old 05-07-2012, 03:56 PM   #5
I'm Your Huckleberry
 
Join Date: Mar 2011
Posts: 5,556
Default

Wires on Fire


If all professionals were of your caliber than us tradesmen would be better off joing the fire department.
__________________
Thanks.
Doc Holliday is offline   Reply With Quote
Old 05-07-2012, 04:11 PM   #6
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


Doc Please,

Slow down, jb 64 is my birth year. In '85 I worked on motor control centers and fire pump controlers in and around Chicago. 480v standing in water, electrical explosions, common, worked on 5100 volt controls. I never asked what current should it draw, no questions about wire size, just looking for local residential experienced person.
jb64 is offline   Reply With Quote
Old 05-07-2012, 04:58 PM   #7
Member
 
Ravenworks's Avatar
 
Join Date: Oct 2010
Location: NE Ohio
Posts: 598
Default

Wires on Fire


My concern is you using those slim breakers,are you sure that you are drawing off of post phases?
Ravenworks is offline   Reply With Quote
Old 05-07-2012, 05:03 PM   #8
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,506
Default

Wires on Fire


1. The fan motor that failed had bushing not bearing, lubricated with "oily sawdust" should I just change it? Flip of the quarter


2. Reversed cooling fan, any more expected problems? Not really.


3. Hard start caps, are they ok or a "band-aid"? helps the compressor get off its locked rotor quicker, which saves the start windings.


4. My breakers are rated for ambient 40C, 104F, in Houston area this is a cool summer day, is it normal to use these? Your breakers are inside your home, the area the breaker is in is not at or above 40C. So they are fine to use.


5. I have slim line GE breakers inside panel, it seems if changed to the wider body breaker it should be able to dissapate more heat? See answer to 4.
beenthere is offline   Reply With Quote
Old 05-07-2012, 05:07 PM   #9
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


Doc,
Maybe I confused you, sorry. I have two 5 ton ac units and one 3 ton ac unit. 1 of the 5 ton has no freon, its off. The other was the original problem with the wires and extra caps. I have that one (wire fire) running since last summer(hot). I measure the current of all routinely, all ok, even when the one with burned wires was in spec.
jb64 is offline   Reply With Quote
Old 05-07-2012, 05:10 PM   #10
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


Beenthere,
Thanks for not joining the fire dept
jb64 is offline   Reply With Quote
Old 05-07-2012, 05:12 PM   #11
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


Bt,
Breaker boxes for each unit out by the condensers, inside breaker boxes in garage.
jb64 is offline   Reply With Quote
Old 05-07-2012, 05:13 PM   #12
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,506
Default

Wires on Fire


What size are the breakers, and what size is the max breaker size the condensers list.
beenthere is offline   Reply With Quote
Old 05-07-2012, 05:17 PM   #13
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


BT & Doc,
I mean it, you both really helped with the other unit, its ready for freon. I was having brain problems believing 2.5 mfd difference was going to double the run current, I was way wrong.
jb64 is offline   Reply With Quote
Old 05-07-2012, 05:23 PM   #14
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,506
Default

Wires on Fire


Run capacitors aren't actually used to provide more power to motors. Rather they throw off the sine wave. A small change in uf, can make a big difference in amp draw.
beenthere is offline   Reply With Quote
Old 05-07-2012, 05:25 PM   #15
Member
 
Join Date: May 2012
Location: Houston Area
Posts: 62
Default

Wires on Fire


BT,
Size, amps 60 wide body sq D outside, GE 50 slim in box in garage, all dimensions similar except width, large 1.5", thin 1"

jb64 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
Timer switch has 4 wires. Only 3 wires on switch by itself. Now what. noone Electrical 11 11-15-2011 06:07 AM
installing an electrical outlet with 3 sets of wires + ground dsparks Electrical 7 07-08-2009 06:18 PM
Req: Help connecting circuit breaker and running wires RickDel Electrical 5 05-26-2009 06:38 PM
Confusing Chandelier Wires Burnsy Electrical 21 02-22-2009 03:29 PM
Old house, new light fixture, too many wires Persephonee Electrical 3 01-15-2007 08:58 AM




Top of Page | View New Posts

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