START YOUR TROUBLESHOOTING IN THE RIGHT PLACE!
by Kenneth Ripberger, KR Services
The most exasperating part of using a telephone to help a technician diagnose a problem, is the fact that YOU can't see what the technician is seeing. Many service managers have to develop a bit of Extra-Sensory-Perception, along with their crystal ball and Ouiji-board, in order to come up with a suggestion or solution for the Lost Soul in the field.
When the trouble seems to stem from a refrigerant circuit problem, the show can only began with the magic key. Merlin, the service manager, therefore asks Mr. Lost Soul:
WHAT IS CONTROLLING THE REFRIGERANT?
If that answer is not known, then everyone is from that point forward, simply wasting a lot of time. We will soon see why this is important, but Merlin has noticed that this frequently pops up as a roadblock. Mr. Lost Soul responds:
I THINK IT USES AN ORIFICE BECAUSE I SAW THE TAG ON THE COIL.
At which point Merlin sighs, stops waving his magic wand and puts it down, and then takes a sip of his coffee. He has been down this road too many times to fall for that one, and says:
WE HAVE TO KNOW FOR SURE WHAT THE REFRIGERANT CONTROL IS. DO YOU HAVE A TXV, A CAP TUBE, OR AN ORIFICE?
Now Merlin can predict so well, (remember his ESP!) what the next line from Mr. Lost Soul will be, that he lip syncs it perfectly when it is spoken:
WELL I COULDN'T SEE IT BECAUSE IT'S REALLY HARD TO GET TO, AND IT'S DARK AND KIND OF HOT, AND THE SCREWS ARE RUSTED AND I DON’T EVEN THINK THE PANEL COMES OFF ON THAT COIL, AND SOMEONE TOLD ME BEFORE THIS ONE ALWAYS HAS AN ORIFICE, (Takes a long needed deep breath) AND WHY DON’T WE JUST CONDEMN IT AND CHANGE EVERYTHING IT'S REALLY OLD!
Now Merlin is peeling open another pack of cigarettes, his third today. He knows this system was just installed last week. He also knows that his company has had some mix ups with new coils because the expansion valves have been on back order. He stays cool and says:
OK MR. LOST, PLEASE DO ME A PERSONAL FAVOR, REMOVE THE FOUR SCREWS ON THE PANEL, CHECK IT FOR ME AND CALL ME BACK WHEN YOU GOT IT. I HAVE TO GO TO THE BATHROOM REAL BAD, BYE!
No sense going any further. The technician had reported a 90 psig suction with a 240 psig head. He didn't see any sweat on the suction line and was getting ready to condemn the compressor. This particular technician, Mr. Soul, had a few years experience in installing apartment complex units, and knew that these symptoms just HAD to indicate bad valves.
With typical low-cost equipment that usually employs a fixed orifice metering device, that diagnoses may have held water. But Merlin wasn't going to waver from his cardinal rule, that's why he made the big bucks. Thirty seconds later, Mr. Soul is back on the line:
IT HAS AN EXPANSION VALVE! I'VE GOT THE NUMBERS ON IT AND I BET THAT'S WHAT RUINED THE COMPRESSOR!
Merlin is having visions of the Florida coast dance through his head, just like in the commercials, and considers laying down for a while. But now he can move forward, so he picks up his magic wand again:
PUT AN ELECTRONIC THERMOMETER ON THE LIQUID LINE AND GIVE ME A READING. AND IF YOU ARE GOING TO TELL ME YOU DON'T HAVE ONE, THEN PUT YOUR CALIBRATED FINGERS ON IT AND TELL ME IF IT'S REAL WARM.
Merlin reminds himself that this is what he does best. Sometimes a magician has to work around all the usual roadblocks, and interpret some technician's "fuzzy logic" responses. He knows Mr. Soul will need some extra training, but he's also aware that what is going on at this minute may be some of the best training there is. Mr. Soul calls back on the cell phone again, very excited, with enough emotion to put Robin Williams to shame:
I UNWRAPPED MY NEW ELECTRONIC THERMOMETER I BOUGHT LAST YEAR, AND IT SHOWS 115 DEGREES, AND THE LINE FEELS VERY WARM. I FOUND A CHART IN THE UNIT THAT SHOWS A SUBCOOLING CURVE FOR TXV SYSTEMS. SO I FIGURE THERE'S NO SUBCOOLING GOING ON, AND SO I ADDED SOME GAS. IT'S RUNNING GREAT NOW AND THE SUCTION DROPPED TO 80. I GUESS THAT'S WHY YOU WANTED TO KNOW THE CONTROL TYPE. THANKS BOSS, I CAN TAKE IT FROM HERE! I'M GOING TO HELP YOU REMIND ALL THE INSTALLERS THAT THEY HAVE TO KNOW WHAT THEY HAVE BEFORE THEY CHARGE THESE THINGS! BYE!
It was also an eye opener for Mr. Soul, to finally put to use his expensive tools, which he had purchased to impress people with. Mr. Soul can now officially change his nickname to Mr. Technician. He has just made that leap from whiner to professional. Even Merlin was shocked when the tech support process leaped forward so quickly. He didn't even get to recite his speech; that fixed orifice and cap tube systems rely on the superheat readings for charging and diagnoses, as opposed to expansion valve systems which use the subcooling characteristics for charging, and most diagnostics. Merlin never heard back from him after that day, except when Mr. Technician invited him to his new Florida beach condo. You see. Mr. Technician makes the big bucks now too.