license to handle R22a refrigerant gas ?

R22a will operate successfully on either mineral or POE oil.Your system would have POE oil if it was originally designed for R407c.

Changing oil in a sealed system can be done but is difficult,we have done it many times.Most systems it has to be done more than once to get the percentage of old oil in the system below the correct amount.This is checked using a refractometer.

I would get it filled with the refrigerant it was designed for and then forget about it.......,particularly as R407c is readily available and at a reasonable cost on todays market.

And those domestic fridges use very small amounts of refrigerant(600a),we are talking less than 100grms.

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Originally Posted by scarry

R22a will operate successfully on either mineral or POE oil.Your system would have POE oil if it was originally designed for R407c.

Changing oil in a sealed system can be done but is difficult,we have done it many times.Most systems it has to be done more than once to get the percentage of old oil in the system below the correct amount.This is checked using a refractometer.

I would get it filled with the refrigerant it was designed for and then forget about it.......,particularly as R407c is readily available and at a reasonable cost on todays market.

And those domestic fridges use very small amounts of refrigerant(600a),we are talking less than 100grms.

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I agree.

Back when I started doing oil conversions to POE in about '91 (on larger, open drive systems) Castrol's recommendation was three fluid changes would get the level of mineral oil below 1% in the entire system.
This was deemed ok for efficient operation and good oil return when converting R12 to R134a, etc.
I did this on several large dairies with DX systems with very good success.
It also saved taking a sample and using a refractometer (which I was too lousy to buy :angel:)

"particularly as R407c is readily available and at a reasonable cost on todays market"

Are things different in QLD? I was quoted about $100.00/kg and Im in the trade.

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Originally Posted by rick130

I agree.

Back when I started doing oil conversions to POE in about '91 (on larger, open drive systems) Castrol's recommendation was three fluid changes would get the level of mineral oil below 1% in the entire system.
This was deemed ok for efficient operation and good oil return when converting R12 to R134a, etc.
I did this on several large dairies with DX systems with very good success.
It also saved taking a sample and using a refractometer (which I was too lousy to buy :angel:)

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Agreed,but we were doing many Govt. jobs and had their inspecters checking up on us,everything had to be documented.

We also had to drain the oil separaters on all systems that had them,and refill with the new oil.If this wasn't done,many systems took over 5(sump) oil changes to get less than 3%,which was specified.

On the sealed units we use to silver solder a schrader valve into the sump,worked well,never had an issue.

We were using Castrol oils as well,they were very helpful.

We also had to change all the shaft seals,solenoid valves and any other items that may have had rubber seals,such as sight glasses and hand valves.

We did hundreds of systems and never had a problem,i don't think we ever adjusted a TX valve.Pressure switch settings needed adjusting,particularly the HP,going from R502 to R507.They specified R507,not 404a.(basically same stuff anyway,we have mixed it successfully,never had an issue)

The best thing was we were able to keep all the reclaimed R12 and R502:):)
As there was nothing in their spec saying what to do with it once it was reclaimed.

Now we all have the same challenge again,replacing R22......

Back when I was buying and selling used cars, one could buy cans of Freon with some hose and fittings at many auto stores. K-Mart used to sell them. Over the counter and no questions asked. Dead easy to top up the systems that needed it as a sales point. "This lovely original (low dog) car has working a/c". When a mate was closing and clearing out his wrecking yard and workshop about 2-3 years ago, he found a couple of gallon cans of Freon squirelled away on shelves in the back shed.

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Originally Posted by northiam

"particularly as R407c is readily available and at a reasonable cost on todays market"

Are things different in QLD? I was quoted about $100.00/kg and Im in the trade.

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Must be,i bought some last week for around 30% less than that plus GST.

R22 is over $100,and going up GRRRRRRRRRRRRRRRR:mad:

I think the only readily available common synthetic refrigerant cheaper than 407c is 134a

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Originally Posted by FFR

Hi Dave,

hey, look at us, we have land rovers. It is not about common sense and practicality... it is all about learning how things work, you know what I mean.

Because R22a is as dangerous as the petrol or the LPG bottle, I suppose that the requirements to handle it in Australia will be easy to fulfill, if any (as mentioned before, no requirements in western countries)

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I feel where you're coming from and having seen some of the stuff that guys who hold much better AC liscences than me have tried on truely wish that we could go back to how it was before someone decided we need to listen to the greenies.

ATM, take your pick of refrigerants from R8 through to the 600 series and in Australia it doesnt matter, if its sold as a refrigerant and if the guy at the point of sale is doing his job you're not going to get it without a liscence.

I have cert II / III in Aircon and I cant buy the stuff because to get a liscence I need to have cert IV. My employer (the ADF in this case) can buy the stuff and I can then use it.

roughly outlining the certifications

Cert I is basically identify all the component of the system where they are, how they work and non invasive system diagnostics (electrical checks ,this bit gets hot this bit gets cold)
Cert II gets you to invasive testing and basic repair (plug on gauges, remove simple components, gas handling purge vac procedures)
Cert III lets you build up and install predesigned systems (think kits)
Cert IV get you to buying the gas and making system design changes (based on obsolescent parts/gas changes)
Cert V lets you design from scratch and make system design changes based on performance.

From what I remember about the hydrocarbon gas, if the system is going to be setup in an enclosed non ventilated area (auto bodies count which is why I remember the 30% rule) and the refrigerant is more than 30% flamable gas by weight and/or the weight of the portion of the refrigerant that is flamable is over a certain weight (which in auto world it only is in the largest of busses so I dont remember the weight but Id guess its something like >1kg) Then there are rules that govern the requirements for fitting additional safety gear and warning systems.

I dont usually reccomend using hydrocarbon heavy gas, not because it can go foom or because its less effecient (theres ways around that) but because usually it has a requirement for different seals/lubes than the gasses I routinely replace and being flamable has a different storage class than non flamable refrigerants.

I recently renewed (to long expired) my full RAC with the artick (Dept of environment etc) they rejected my application as I only had a
"certificate of proficency refrigeration mechanics"
After a lot of bs and many days someone there finally knew what a COP was. :censored:
I had to explain to the so called govering agengy that you only obtain of cert of proficieny after successfully completing a indentured apprenticeship
I have since received my renewal

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Originally Posted by FFR

AFAIK, from what I have been reading on whirlpool forums, a car running an aircon with R22a or other hydrocarbon must have a big sticker under the bonnet, so any mechanic will treat the vehicle as if it were an LPG.

My original question was about getting some kind of restricted license to handle hydrocarbon refrigerants, and apparently there are two National Accredited Units (UEENEEJ174A and UEENEEJ175A) related with the use of hydrocarbons, and a single, part time TAFE course to do split systems installs of up to 18 kW, after that (and some other requirement, maybe) you can apply for a restricted refrigerant license. But I'm just searching for info, all this stuff might be outdated or wrong.

Yes, there are one thousand things that can go wrong everyday with petrol and other volatile hydrocarbons... but at the end of the day it is only an aircon running propane. If if were risky then it would be banned. I think that having 250 grams of propane in the roof is nothing compared with 100 liters of petrol in the rear tank. But this is only a personal opinion.

Many thanks for your responses. :)

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Sorry, I thought I'd been clear on that point. A restricted refrigerant licence DOES NOT allow you to charge, recover, or work with the refrigerant in any way. Even with a full licence, you cannot legally buy refrigerant. You need a Refrigerant Trading Authorisation (a purchasing licence) to legally buy refrigerant, as well as the full Refrigerant Handling Licence. The RTA is held by the company (as far as I know it's not available to individuals, but I could be wrong. Never needed to find out) so my employers have the RTA & buy the refrigerant. I then use that refrigerant under my full refrigerant handling licence. Which is why I said you'd need to set up a company having got your qualification & full refrigerant licence to buy the stuff.

My Scarry & Rick130 are right of course in that you can change the oil in a hermetic system, however it's a lot more difficult.
I have done it a few times, most memorably on a large order of Trane packaged units. It's a lot of work, & you may end up damaging the compressor beyond repair. I reckon it's a prohibitively expensive option in your case. Sorry if I gave the impression that it simply cannot be done.

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Originally Posted by northiam

I recently renewed (to long expired) my full RAC with the artick (Dept of environment etc) they rejected my application as I only had a
"certificate of proficency refrigeration mechanics"
After a lot of bs and many days someone there finally knew what a COP was. :censored:
I had to explain to the so called govering agengy that you only obtain of cert of proficieny after successfully completing a indentured apprenticeship
I have since received my renewal

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Many, many went through the same crap.

My TAFE certs weren't recognised by the ARC initially as my quals are from NSW and were from prior to 1990 even though they were the required modules for commercial/industrial a/c and refrig through the NSW TAFE system, as required for the then apprenticeship programme to gain a full trades qualification :rolleyes:
I'd been servicing, building and designing systems for years and contracted as a consultant on a couple of NSW Hospital AC jobs :lol2:

When the ARC system came out it was all based on the Vic TAFE modules and course numbers. They didn't seem to recognise anything from the other states that was over ten years old, even though it was supposedly a National system.
Sheesh, I'm not that bloody old. :o

It was an absolute schemozzle.