Digital guage dilemma
I went to go replace a leaky Comfortmaker evaporator coil today. Nice sunny day, 75 degrees this morning, coil was located in a cape cod type attic, so everything was set to be perfect. In a little over an hour, I had a new filter drier on, the new coil in place, all my joints looked factory - as they always do. Only bad thing that's happened so far is I set off the smoke alarm and scared the poor lady. Oh well. I pressurize the system with nitrogen, check for leaks - none of course. Pull a vacuum and after 30 minutes, I'm down to 95 microns - I was REAL happy.
So I go to open the service valves and start it up. Everything is purring along nicely - wait, what's this? 18 degrees subcooling? Hmm, let me run it a little longer.
22 degrees subcooling? Now that pit in my stomach is growing. What did I do - did I damage the TXV, was nitrogen not flowing and I stopped up the strainer? Non-condensables maybe? Surely it'll clear up.
25 degrees subcooling. GREAT! 3 hours and this job has been nothing but perfect, now I'm going to have to pull the charge and start all over!
Wait - my LL temperature is 67 degrees? Surely that can't be right because it's at least 80 degrees out now. I take my clamp off the liquid line and my temperature keeps going down into the 50s. I put my stick thermometer on and I'm reading 10 degrees subcooling on the dot. So everything was just fine, except my clamp...
This is what I hate about digital gauges.
Yea.....That could be a problem. Or when you do your A/C work dealing with 90% Magic Pak PATC type units, from Condos, Apts, student housing, 55+ communities...... Watching the look of the maintenance mans face is PRICELESS!!!!!!
That has not happened with my digi cools....
Originally Posted by CircusEnvy
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
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