Phillip Posted December 27, 2008 Report Share Posted December 27, 2008 Here in Alabama we do not have that much cold weather. Sunday and Monday was cold and the rest of the week has been up in the 60s and 70s. This time of year I will shoot the temp on the compressor casing before I test it. If the temp is too low I will not run them. On todays inspection I shot the casing and it was 111.3. I shot the fan housing and it was 78. What would cause this higher temp?Click to View 53.96 KB Click to View 59.62 KB Quote Link to comment Share on other sites More sharing options...
AHI in AR Posted December 27, 2008 Report Share Posted December 27, 2008 They have been running the AC. Quote Link to comment Share on other sites More sharing options...
Phillip Posted December 27, 2008 Author Report Share Posted December 27, 2008 No one lives at the house. Quote Link to comment Share on other sites More sharing options...
energy star Posted December 27, 2008 Report Share Posted December 27, 2008 The crankcase heater was on. A heater, either wraps around or is installed in the compressor to prevent the the migration of liquid refrigerant to the compressor (out side) R-22 will always go to the coldest area in the system. A compressor is designed to pump gas not liquid. (Scroll compressors have less of a problem) So after a long sit in the cold, and the first start up occurs a gas is present, not liquid that will slug up the compressor and perhaps damage it. I do not know why the the fan shroud or casing was a bit warmer? Heat gain from the sun. I would not think that the crankcase heater would generate the much excessive heat, but I could be wrong. I find I do get things wrong more than I would like. Ha ha. Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted December 27, 2008 Report Share Posted December 27, 2008 It may have been running if the thermostat was set for automatic operation. Did you happen to notice the switch setting on the thermostat? Is this a heat pump? I've seen external crankcase heaters that get pretty hot. Quote Link to comment Share on other sites More sharing options...
Phillip Posted December 28, 2008 Author Report Share Posted December 28, 2008 The unit is a Traine straight cool unit 27 year old. The thermostat was set on off. There is no external crankcase heater. The unit was setting in the sun and outside temp was 62. Quote Link to comment Share on other sites More sharing options...
energy star Posted December 28, 2008 Report Share Posted December 28, 2008 Then its inside the compressor, but it has a heater. 27 years old, I hope you told them it's time to replace? Whats the model # One more point. Have some fun. Go grab two items you can toss in the oven and heat to 150 or 200 degrees. Set one 3" from your temp gun and one about 16" from the gun. Even though both rocks (or whatever) are heated to the same temp, you will get two different readings. Quote Link to comment Share on other sites More sharing options...
hausdok Posted December 28, 2008 Report Share Posted December 28, 2008 Originally posted by energy star Have some fun. Go grab two items you can toss in the oven and heat to 150 or 200 degrees. Set one 3" from your temp gun and one about 16" from the gun. Even though both rocks (or whatever) are heated to the same temp, you will get two different readings. Yeah, but with some sour cream, chives and some bacon bits both will be delicious. ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted December 28, 2008 Report Share Posted December 28, 2008 Originally posted by hausdok Originally posted by energy star Have some fun. Go grab two items you can toss in the oven and heat to 150 or 200 degrees. Set one 3" from your temp gun and one about 16" from the gun. Even though both rocks (or whatever) are heated to the same temp, you will get two different readings. Yeah, but with some sour cream, chives and some bacon bits both will be delicious. ONE TEAM - ONE FIGHT!!! Mike But hard on the choppers. Quote Link to comment Share on other sites More sharing options...
energy star Posted December 28, 2008 Report Share Posted December 28, 2008 OK, You got me. I guess a baked potato would be better. At least when done with this simple experiment you could eat it. Quote Link to comment Share on other sites More sharing options...
inspector57 Posted December 28, 2008 Report Share Posted December 28, 2008 I would be concerned about an error using the ray gun outdoors with different reflectivity on different surfaces. Did you touch the surface to confirm the readings were in the right ball park? I have and use a infrared thermometer, but I always am aware of the possibility for errors, especially on shiny surfaces. Quote Link to comment Share on other sites More sharing options...
Phillip Posted December 29, 2008 Author Report Share Posted December 29, 2008 I shoot the casing all the time and there are always around the same temp as the housing of the fan and the outer cover of the unit. Most of the time the outer cover of the unit and the fan housing is warmer then the compressor casing since the sun hit them more. I know there is a different in the temps in different distances and different surfaces. Quote Link to comment Share on other sites More sharing options...
Phillip Posted December 31, 2008 Author Report Share Posted December 31, 2008 To day the sun is shinning and the temp is 59 degrees. I when out and shot the temps on my heat pump unit. It is one year old Goodman. The exterior of the unit was 57.5 Click to View 60.93 KB The fan housing was 77.5 Click to View 73.81 KB The compressor casing was 75.2 after being on and running today. Click to View 86.63 KB Quote Link to comment Share on other sites More sharing options...
steve morris Posted January 4, 2009 Report Share Posted January 4, 2009 On a TRANE unit of that vintage the mfg. uses the start winding in the compressor as a crankcase heater.(I believe this is a bad idea,Florida being the lightning capital of the country, a lot of shorted start windings) The temp. you stated is a little high, it may have other problems and the compressor is cyling on the internal t-stat embeded in the winding. When the control contactor goes bad some a/c tech.(for lack of a better name) may have miss wired the new one in, I found them all the the time when I was in the business. Quote Link to comment Share on other sites More sharing options...
energy star Posted January 6, 2009 Report Share Posted January 6, 2009 Phillip, when you tested the 27 yr old unit in post # 1, did it seem to operate ok? What was the outside temp? Quote Link to comment Share on other sites More sharing options...
Phillip Posted January 7, 2009 Author Report Share Posted January 7, 2009 Originally posted by energy star Phillip, when you tested the 27 yr old unit in post # 1, did it seem to operate ok? What was the outside temp? It cooled but did not have much of a temp change. The outside temp was 62 degree. see post # 9 Quote Link to comment Share on other sites More sharing options...
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