Hmm,exactly,me to:DQuote:
Originally Posted by rick130
Hope the caravan A/C gets sorted......:)
maybe we need a yack yack thread for the fridgies on here:angel:
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Hmm,exactly,me to:DQuote:
Originally Posted by rick130
Hope the caravan A/C gets sorted......:)
maybe we need a yack yack thread for the fridgies on here:angel:
Yea you both have gone off topic, but it's making me smile along the way, I too come form a Kelvinator heritage as well as rebuilding Bock, Grasso, Trane etc. I also would say the Trawler guys used to love T's and Y's, when I was living in Hervey Bay I used to spend time with an old skipper that used to rebuild T after T, he bought bucket loads of parts when they closed up the Teneriffe distribution wharehouse so figured he would keep rebuilding till he ran out, used to see some interesting repairs... ahhh the good ol' days:D
:-) 32 years as a fridgy, and I'm on the national body that develops the training packages that apprentices learn and trainers teach.
perhaps there is a need for a fridgy question threads - I'm bloody passionate about my trade.
and as far as the actual question goes - propane is not covered by the Arctick license, but you must display a sticker stating that a hydrocarbon refrigerant is in the system
P.S. get a fully qualified fridgy to help :-)
I know this is way OT,hope the OP does not mind,but the training the A/C&refrg. apprentices get today(in Brisbane) is absolutely nothing near the quality we got 35 yrs ago:mad:Quote:
Originally Posted by blitz
Could be the quality of the teachers,not necessarily the stuff they are supposed to teach.
Quote:
Originally Posted by scarry
Yep, this will be my 35th year and I totally agree the training is ****e, I have even been asked if I am a Refrigeration Mechanic or and Air Conditioning Mechanic by a younger "Tradesman"....... I'm starting to get up on a soapbox so will sit down again
Its a fair distinction today in my book....
Airconditioning mechanic is a guy who fixes car AC and make the car go bits.
Refrigeration mechanic does pretty much everything else thats refrigeration related (possibly not evaporative stuff, but this side of the house is not my world). (they also usually have some limited sparky quals as well)
Typically at work when someone wants AC work done on their car they come in asking for an Air con Mechanic, When they want the fridge or their wall mount AC fixed they coming asking for a fridgey.
Either way, I usually wind up doing both.
[
perhaps there is a need for a fridgy question threads - I'm bloody passionate about my trade.
P.S. get a fully qualified fridgy to help :-)[/QUOTE]
Yes I would agree!
As a transplanted Pom in the US, I sat and passed the EPA tests for stationary and mobile A/C systems. That was in the 90's when R22 and R12 (freon) was the norm in cars. Of course on the horizon was the R134a refrigerant and conversions for existing mobile units. In those days I made a good living converting R12 to R134a existing systems. As a plus always had a few devotees asking me to fix stationary systems like those through the window A/C plants.
Yes I am passionate about the business too, because when you get it right, by following the "nouse": you have built up by experience and training you get very happy customers. I would say that in the auto business its the best way to get satisfied customers, and fewer griping about the bill!
That was then, this is now!
These days the mobile licensing in the US has been stood on it head.
First any Tom "Dick" or Harry can buy R134a in dispensing cans with a whip hose from a parts store and charge it himself. Small, big and "super size" cans line the shelves complete with its own oil and "leak stopper brew" mixed into the refrigerant as a magic fix it all.
Of course it rarely does and that's when I see it!
My problems are, being licensed I have to have expensive equipment to recycle the brew which is often contaminated.
Most cans have a stop leak additive which buggers up my hose connectors or internals in the machine, not to mention the vehicle it is in when its time to properly repair it.
So I have to have add on kit to detect this stuff. Then use a semi crooked machine to suck the stuff out!
Now I haven't mentioned Hybrids like the Prius. The Gen 2 and on have an electric A/C compressor; so no drive belt!
Run by an internal electric motor the refrigeration currently is the same (R134a) but the lube oil is different to stop shorting down of the internal "lekkie" motor by moisture suspended in the oil medium. I have lost count of how many I fixed last year where "Dick" had charged it with the universal can of 134a from the parts shelf only to have a car shut down due to internal short circuiting!
Now this isn't cheap , a new compressor is around $3000 (no typo) retail a new condenser with sealed in situ receiver drier is $1500. Add the labour and it comes out to around $5000 to fix what would have been a cheapish job to put right in the first place.
The same goes to a certain extent with APU systems on big trucks. Most use R417a and the old R22 but every so often I will come across a system that is down on efficiency. The last one I fixed in a Kenworth W900 had some "Wally" in a truck stop who should have known better, had bunged in a charge of 134a with a goodly dose of synthetic oil. The mix of mineral and syn oils made a right old bloody mess.
Training again I suppose!
Anyway as the saying goes "If this stuff was it was easy everyone would be doing it:cool:
On a satisfaction index the job has some satisfaction. A few years back I had to go to a local sand and gravel company to look at a truck A/C system. At the weight bridge was a wooden shack with about 5 ladies in it dressed in tee shirts and shorts all sweating. Being a bloody hot Colorado day the A/C through the window type was chugging away without much success. Taking a quick look at the outside condenser, the problem was evident thick caked on mud all over the matrix.
A few buckets of water chucked on the coils made it go cold fast--real cold! I could hear the exclamations inside the shack like "Looks like the Limey has fixed it"!
After looking at the truck I popped in to see the ladies all sat in cold comfort dispatching trucks. "Chorusly" thanked for the magic application of cold water I commented to one gal with a crumb tray "yea luv" that cold air is working it magic!!!:censored:
Cheers Dennis:D
zedcars
That's a straight moisture thing Dennis, you'd have the same problem in stationary refrig/a-c too.Quote:
Originally Posted by zedcars
Remember stationary refrigeration/a-c has been using inbuilt electric motors since the 1920's, think of any air conditioner or fridge at home, let alone commercial/industrial stuff ;)
Part of the spec for any refrigeration oil is dielectric strength, and any common, over the counter refrigeration oil should sport it in spades.
One of the the other thing is moisture content or dryness, and the specs for this are tight. Very tight.
Polyolesters and PAGs are extremely hygroscopic, the recommendations have always been to use from tins, not plastic bottles (as plastic acts as a membrane, moisture can pass) lids removed only for pouring oil and recapped staright away (although this was standard procedure when using 3/4/5GS all those years ago) and anything not used straight away must be disposed of as it's contaminated (although hands up who 'purges' the tin with dry nitrogen before re-capping for reuse ? :angel:) etc, etc.
Our electrical supply here is like the UK, 240V single phase or 415V three phase, 50Hz, so the problems of moisture breakdown and shorts are real, although the problem usually manifests as acid which then really does lovely things internally as the oil, refrigerant and moisture have a lovely atmosphere to react with the heat inside the compressor.
When we first started using POE's in commercial refrigeration back in the early nineties, Copelands recommendation (and a warranty stipulation) were dryers with double the moisture and acid holding ability of those used previously, purely as the oil was so touchy, and if you are careful and handle everything as recommended, purge systems with dry nitrogen when working, evacuate properly, etc you will never have an acid/moisture problem.
The big problem is the unknowing/untrained, they just don't get how dry and clean you need to be.
Rick
Good post and I enjoyed reading your submission.
Yes those PAGS are very hydroscopic and this was emphasized during a course I took when they first came out for 134a applications. Even in our Coloradan high plains desert atmosphere with about 22% humidity the stuff shows a quick deterioration if left open to the air. My shop blokes think I am being a tiresome old Limey "-----" well you know! Demanding all open pipes/ports be plugged during major vehicle repairs when the A/C has to be disconnected/opened up. Plus using protective eye wear.:(
Mods I think there is definitely a thread on these forums for A/C work whether mobile or stationary. Just for the curious if for nothing else
But you are right Rick, training/unknowing is the issue. In the case of the Prius and other similar Hybrids it can be fatal. With around 257 to 333 volts DC whizzing about in those orange cables One untrained educated idiot with tools could end up permanently dead! :angel:
Cheers Dennis
Kev is talking about the distinction between refrigeration and comfort cooling.Quote:
Originally Posted by Blknight.aus
Mobile refrig/a-c is different again. (although back in the 'old' days we tended to do everything.)
The only difference really between refrig and a/c is evaporating temps, but there's definitely been a distinction between skill sets since I did my time in the early eighties :angel:
The blokes that worked on big commercial a/c systems and worked for the big companies were often trained very well, the fellows that only did domestic/light commercial were only exposed to a narrow range of circumstances and so had a narrow range of experience.
Even when I was at Tech in the early/mid eighties the specialisation was pretty evident.
I was lucky, one day I could be working on a DX milk vat, the next a Temprite beer system, then a major Telephone Exchange air conditioning system, or installing a ducted a/c system in a house.
Each had it's little 'tricks', but if you encountered something new you applied your basics and you nutted it out.
eg. a Dairy Kold milk vat used a fixed orifice metering device and no receiver, they were a critical charge, so to gas one up you needed to put a chaff bag over the condenser and get the discharge pressure to 150psi (R12) and when you achieved a suction pressure of 20psi with a sweaty suction line, that was it, you shut your gauges off otherwise you'd have an overcharge and that'd really slow the rate of pulldown. Not a good thing in a dairy where the temps are closely monitored and often the tanker would arrive just as the last cows are leaving the bails (the condensers were marginal at the best of times too, and all the dairies had the bloody vacuum pump exhaust near the condensing unit, blowing oil all over the condenser.)
You paid no attention to the sight glass, although with those conditions it would actually clear, just.
The first time I encountered one (as a first or second year, yes, I was out on the road by myself :angel:) I hadn't been tipped off to 'this is how you do it' but I got it right by applying the basics, watching my gauges, feeling temps and watching the speed of pulldown.
OK, I fluked it :D
After getting back to the workshop and being asked, "what was wrong" I was then told "this is how you do it" :lol2:
All the other fella's I went to tech with worked in one area only, eg comfort cooling or pub/club work and a lot of them seemed to become brain dead when presented with something slightly outside their field of experience, yet the basic principles are the same.
We actually used to reckon that someone that did their time on commercial refrig could work on anything, but it didn't appear that an a/c bloke could go the other way.
Or is that being biased ? :angel: