apprentices

Hey just wanted your input
Just taken on a apprentice from another engineer. He is kind of set in his ways ie put gauges on - low on gas so top up no rise in suction pressure so expansion valve is blocked is basic of his findings for a job we done .
So my question to you is how do you go about fault finding a cellar cooling system and testing/inspecting a expansion valve?
I want to show him this thread and show him he doesnt neccessarilly need guages to fault find and its not my way vs another , more his hands eyes and ears are just important as guages are and that he will probably find a way that works for him completely different from who trained him anyway
Thanks in advance

buy him qwik couplers- if he's set on fitting gauges to everything- teach him how to check superheat,subcooling, show him a system correctly operating and mark temperatures of liq line,discharge temp, running current etc so he can compare it to a faulty system
or buy him that kotzza software- theres a few questions you can do for free
http://www.simutechsystems.com/
found this

Whats wrong with installing gauges, I thought it was the best basic thing to do if something is wrong!

Going on a limb, but most techs would not install gauges because they are a bit lazy (in my opinion).

I f all you do is cellars, then I guess you could get away with it after awhile of touch & feel.
If there is a sight glass in liquid line & looks OK , suction in cold on compressor, room temp OK, then
its PROBABLY OK.

most people who whack gauges on dont bother with qwik couplers- therefore everytime they maul with it, they lose some of the charge-
i aint endorsing the product in any way but if it means u can connect to a discharge pipe at 33bar and not get burnt they i'll keep using em!

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Originally Posted by install monkey

most people who whack gauges on dont bother with qwik couplers- therefore everytime they maul with it, they lose some of the charge-
i aint endorsing the product in any way but if it means u can connect to a discharge pipe at 33bar and not get burnt they i'll keep using em!

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I don't work with the stuff, but whatever you have to do to read the pressures in the system, the easiest way!
To me you don't have to install on a system every time if its "running OK", but to troubleshoot I
would have thought it was necessary.

I would measure temps with contact thermometer first and foremost, check input voltages, running amps, contactor integrity, correct switching of thermostat, as well as good air flows through condensor and evaps and make sure fans are going in right direction ! If gauges MUST be connected then i would always pump the gauges down by throttling the high side back into low side , pum down unit to 5 psi before removing gauges then fully opening service valves !!!

best way to teach him not to use gauges is to cut all his gauge lines and send him to a call in the middle of nowhere!;)

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Originally Posted by sean1

Hey just wanted your input
Just taken on a apprentice from another engineer. He is kind of set in his ways ie put gauges on - low on gas so top up no rise in suction pressure so expansion valve is blocked is basic of his findings for a job we done .
So my question to you is how do you go about fault finding a cellar cooling system and testing/inspecting a expansion valve?
I want to show him this thread and show him he doesnt neccessarilly need guages to fault find and its not my way vs another , more his hands eyes and ears are just important as guages are and that he will probably find a way that works for him completely different from who trained him anyway
Thanks in advance

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Hi

Just my opinion I would not fit gauges straight away now as previous reply says eyes ears touch systems then temp readings and if all the information is pointing to that use your gauges to confirm.
Just my opinion

Ian

One thing MOB taught me was to slow down. He would usually go into a plant room and just sit and think. Now alright he is a lazy f**k but this highlighted that there is a tortoise and hare approach to fault finding.

fault finding is like making love to a beautiful woman.....

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Originally Posted by r.bartlett

One thing MOB taught me was to slow down. He would usually go into a plant room and just sit and think. Now alright he is a lazy f**k but this highlighted that there is a tortoise and hare approach to fault finding.

fault finding is like making love to a beautiful woman.....

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Not shove it in real quick & then off to the next one..?

Definitely stop and think! Look at the system as a whole before doing anything. It's easy to focus your attention in one place and waste time when the fault could be obvious elsewhere. Fitting gauges is certainly not essential at every service call. Mine usually stay in the van on arrival to a call and during initial system checks. I suppose everyone approaches fault finding differently. As long as you are efficiently finding the faults, the customer and the boss are happy then your probably doing ok... As an apprentice I worked with lots of different engineers and saw many different approaches. All you can do is show your apprentice how YOU like to do things. He will make his own mind up if that works for him or not but when he's out on his own he will always think back to things you've said and things he's seen you do. Be the best role model you can and encourage him to think smart and work safely!

fault finding is like making love to a beautiful woman.....[/QUOTE]

What is making love to a beautiful woman like?? I've never been that lucky! Sometimes the misses looks ok if I'm hammered :D

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Originally Posted by NewmanRef

fault finding is like making love to a beautiful woman.....

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What is making love to a beautiful woman like?? I've never been that lucky! Sometimes the misses looks ok if I'm hammered :D[/QUOTE]


You will be hammered when I forward this onto her facebook account :cool:

Ha ha! Please don't! Who will do my cooking and cleaning...

I have a few options re. gauges.
First, look, listen, smell, feel - in any order that suits you. Many a FGD leak has been located by smell, then sight. ;)
I avoid fitting gauges as much as possible - there's no reason to lose refrigerant if you don't have to, I think. And as Gary keeps saying, it's about moving heat energy, not changing pressures. As a couple of posters have said, use a thermometer first, it doesn't take long to get an idea of what temp's to expect for a given system with a particular refrigerant. For example, I find most recip's with R22 will have a discharge temp of around 75*C in normal operation.
I always use quick connectors on schraeders. However, I have found that the o rings in them tend to give out quite quickly - especially if they dry out - so I now use the tap valve type. Also much easier with higher pressures, like R410a. The other advantage of quick connectors is that they enable you to recover the manifold high side, thus losing less refrigerant (Outside of refrigeration, very few machines have service valves on the compressor).
Next I have individual HP & LP gauges that I use as required - easier to carry (especially where quite a lot of gear has to go up a ladder for e.g.) & again less refrigerant loss than a manifold.
Finally, if I have to start getting really serious, I get my manifold. :)

I used to try and get the apprentice to imagine they were the refrigerant going round the system. Then picture what state they were in in each part of the system, imagine what would make them behave the way the system was. The same with the various components, picture them doing their job now imagine what would happen if they were faulty.

I used to get them to take faulty parts to pieces to see how it failed and also see how it should work.
Drawing out the system is a good idea too.

Recent call to a cold room at a Pub in the middle of no-where. Temperature at 16 degrees C.
Evap fans working and coil was clean and clear of ice. Compressor and condenser fan were working but suction line is warm. There is heat coming off condenser and no temperature drop across the drier. Should i fit gauges now.....Nope.
Just give it a minute and see what happens. Compressor drops out.

Open up the electrics and find it is a small 3 Phase unit and the auto reset overload was cycling when the contactor failed to engage all 3 legs. Just an example of observing before jumping in with gauges.

typical - pop up, post irrelevent hyperlink then dissappear!:mad:

Watch the frost and feel the cold. If it's at the inlet of the TXV, the screen could be plugged. If it's at the distributer only it might need to be opened up or the power head has become weak. Warm the bulb with hand or hot water, If the valve sounds like it is moving gas, but the suction is warm, it's low on refrigerant or drier, solenoid or hand valve are not open enough. If it's not feeding all the distributor tubes, some could be plugged. If it's a small cap tube system, shut the fan off. If I think it's low on gas I leak check before tapping in with a gauge so I find if it's on the schrader valve.
If you add gas and don't find a leak, lie and say it was the schrader valve. ha ha.
If there is a port to put a gauge on a non critically charged system, put it on. Writing the pressures down on your work order makes them think you are smart.

During ppm works if no Service valves available don't connect gauges, unless not reaching set point will investigate further. However, had a call on a newish J&E Hall yesterday at a pub, temp slowly creeping up according to customer, +15 degrees checked cellar temp, pipework (on r410a) air off/on the same mmmm get l.p. line on check pressure yep down to 1bar. Lost 1.2kg, found liquid flare nut cracked. I agree don't wack gauges on for the sake of it but if after a good investigation I.e. running amps, pipe temps etc don't be afraid to check the pressures IMO! Obviously depends on the job

Lucky we are not doctors! Blood pressure, heart rate hope for the best until it does'nt work or have symptoms.