One for the fridgies

Des, all the gear I work on with a can has test pressure test limits on the comp and low side, the comps usually have it in the fine print on the rating plate somewhere.
E.g. Anything on R410a you cannot pressure test at high side pressures, the same with R404. IIRC R410a chillers have a test limit of around 25 bar on the low side, even the RC/heat pump one's, but the high side can be tested at something like 40+bar.
When I used to do installs I'd pressure test the pipe work at near max discharge pressures for both sides, and obviously RC AC can take it, too.
Anything with an aluminum evap I'd be careful. A number of big supermarket freezer cases have aluminium evaps on R404a but even +30° is only roughly 190psi

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Originally Posted by rick130

Des, all the gear I work on with a can has test pressure test limits on the comp and low side, the comps usually have it in the fine print on the rating plate somewhere.
E.g. Anything on R410a you cannot pressure test at high side pressures, the same with R404. IIRC R410a chillers have a test limit of around 25 bar on the low side, even the RC/heat pump one's, but the high side can be tested at something like 40+bar.
When I used to do installs I'd pressure test the pipe work at near max discharge pressures for both sides, and obviously RC AC can take it, too.
Anything with an aluminum evap I'd be careful. A number of big supermarket freezer cases have aluminium evaps on R404a but even +30° is only roughly 190psi

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And a bottle of Dry Nitro? I have forgotten most of that stuff where once it was second nature, but you are using different refrigerants today.

I wonder if anyone has ever blown a Can in half at the weld? Never heard of it but you can bet sometime, somewhere, somehow, it has been done.:soapbox:

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Originally Posted by 4bee

And a bottle of Dry Nitro? I have forgotten most of that stuff where once it was second nature, but you are using different refrigerants today.

I wonder if anyone has ever blown a Can in half at the weld? Never heard of it but you can bet sometime, somewhere, somehow, it has been done.:soapbox:

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Naa, you'll blow the glass plug out of the terminals long before anything else let's go

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Originally Posted by rick130

Naa, you'll blow the glass plug out of the terminals long before anything else let's go

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Oh yeah there is that [bighmmm] but I was talking BOOM BOOM Baby.

So for something different out Wacol way,at one of the ‘motels’ for the undesirables,they loaded a cold room with 80 milk crates of milk,6.00am yesterday morning.

Locked it up.

Somehow ‘someone’ had shoved a plastic spoon into each evap fan motor blades.[bigsad][thumbsupbig].

So this morning when they opened the room up,not only was the room full of a burning smell,that is still lingering,but all the milk is being tipped down the drain.[bighmmm]

Oh well,keeps us in work I suppose.[biggrin]

Rick,yes we used to pressure test everything to 300 PSI,with dry nitrogen and leave for at least 24 hours.
But we always used to remove the low side pressure switch,as some brands are not happy with those types of pressures.
Some jobs we even went to 400.

Then a vacuum down to minimum of 200 microns,on new jobs,some were speced to 150.
Vacuum will always let you know if there is a leak,and at times quicker and more definitive than pressure,but mainly on new systems,didn’t work as well on older systems due to gaskets and seals weeping,refrigerant boiling out of oil,moisture,etc.

With auto air,or as said,anything with an aluminium evap,test pressures need to be a lot lower.

Quote:

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Originally Posted by scarry

So for something different out Wacol way,at one of the ‘motels’ for the undesirables,they loaded a cold room with 80 milk crates of milk,6.00am yesterday morning.

Locked it up.

Somehow ‘someone’ had shoved a plastic spoon into each evap fan motor blades.[bigsad][thumbsupbig].

So this morning when they opened the room up,not only was the room full of a burning smell,that is still lingering,but all the milk is being tipped down the drain.[bighmmm]

Oh well,keeps us in work I suppose.[biggrin]

Rick,yes we used to pressure test everything to 300 PSI,with dry nitrogen and leave for at least 24 hours.
But we always used to remove the low side pressure switch,as some brands are not happy with those types of pressures.
Some jobs we even went to 400.

Then a vacuum down to minimum of 200 microns,on new jobs,some were speced to 150.
Vacuum will always let you know if there is a leak,and at times quicker and more definitive than pressure,but mainly on new systems,didn’t work as well on older systems due to gaskets and seals weeping,refrigerant boiling out of oil,moisture,etc.

With auto air,or as said,anything with an aluminium evap,test pressures need to be a lot lower.

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S'funny (in a manner of speaking) that, Plus pinching/breaking off the TEV capillary might get me out of a hole if ever I was locked in & they buggered off home. If it was accessible that is. I mean what Fridgie carries plastic spoons in their kick, more a Screwdriver imho. Better yet.

What a bloody waste of good product just to cause mischief. They need rooting, sorry, Shooting, as they may enjoy the former & we couldn't have that now could we? Taxpayer pays as usual so bugger it.


A bod/Screw, who worked at one of our Labour Prisons( & there is a joke in itself) told me the kitchens had to cook many hundreds of Boiled, Fried, Scrambled eggs each day for, wait for it, just in case the guests all required all sorts of googs, consequently they were all binned because no one did & this supposedly happened each day. Not malicious like your story but it really amounts to the same thing I suppose.

If it wasn't done they were scared of a Riot apparently.


Actions like this make me sooooo annoyed.

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Originally Posted by 4bee

Actions like this make me sooooo annoyed.

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What we see and hear about is only the tip of the iceberg.[bigsad]

At the Youth center the latest is to pour water down the back of the TV,so it blows the arse out of it.[bawl]
No problems,the new one will arrive the next day....

Quote:

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Originally Posted by scarry

So for something different out Wacol way,at one of the ‘motels’ for the undesirables,they loaded a cold room with 80 milk crates of milk,6.00am yesterday morning.

Locked it up.

Somehow ‘someone’ had shoved a plastic spoon into each evap fan motor blades.[bigsad][thumbsupbig].

So this morning when they opened the room up,not only was the room full of a burning smell,that is still lingering,but all the milk is being tipped down the drain.[bighmmm]

Oh well,keeps us in work I suppose.[biggrin]

Rick,yes we used to pressure test everything to 300 PSI,with dry nitrogen and leave for at least 24 hours.
But we always used to remove the low side pressure switch,as some brands are not happy with those types of pressures.
Some jobs we even went to 400.

Then a vacuum down to minimum of 200 microns,on new jobs,some were speced to 150.
Vacuum will always let you know if there is a leak,and at times quicker and more definitive than pressure,but mainly on new systems,didn’t work as well on older systems due to gaskets and seals weeping,refrigerant boiling out of oil,moisture,etc.

With auto air,or as said,anything with an aluminium evap,test pressures need to be a lot lower.

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I don't trust vacstats, so I choose the one that reads the lowest! [emoji23]

I've had a number of chillers take three days to pull down and still not get where I want, re pressure test, think I have a leak and then use the apprentices vacstat and it was sub 400 micron and held. [emoji849]
One chiller I even used Trace-a-gas which has hydrogen in it, as I thought I had a leak.

We clean them, we plead with them, we abuse them, threaten to melt them down, all to no avail, they seem to do their own thing? [emoji53]

Quote:

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Originally Posted by rick130

I don't trust vacstats, so I choose the one that reads the lowest! [emoji23]

I've had a number of chillers take three days to pull down and still not get where I want, re pressure test, think I have a leak and then use the apprentices vacstat and it was sub 400 micron and held. [emoji849]
One chiller I even used Trace-a-gas which has hydrogen in it, as I thought I had a leak.

We clean them, we plead with them, we abuse them, threaten to melt them down, all to no avail, they seem to do their own thing? [emoji53]

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And if Apprentices still do not knuckle down we ditch them. Roight Rick?[bigrolf]


Still trying to understand how a plastic spoon can stall a fan motor like that? Either the motors are **** weak with little torque or the plastic spoon was summat out of the Kitchen with a handle 6" thick & really, really wedged in.

No doubt some one is looking for dabs to match up with the miscreant. "Oh Hello, it was the Head Chef or a 100 other suspects. Case closed" [bigrolf]

Quote:

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Originally Posted by rick130

We clean them, we plead with them, we abuse them, threaten to melt them down, all to no avail, they seem to do their own thing? [emoji53]

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The apprentices, the chillers,or the Vacstats.[bighmmm][biggrin]

In another life,when I did many years of commissioning, apart from leaks,moisture was the biggest issue with trying to get good vacuums.We used to purge every largish system with a full large bottle of medical grade dry nitro, before starting.Had heaps of success doing this.The suppliers of the standard dry nitrogen could not guarantee it was dry.The medical grade always sorted out the issue.

Des,what I recon they did is turned the switch to the fans off,its pretty easily accessible on that particular room, then set the spoons up.We also found a heap of spoons in the condensate tray,so I recon they have had a few goes at doing it before being successful.The fans are standard 300mm,the spoon will slide up through the guard and jam it, pretty easy to do, once you work it out and they have the luxury of having all day to work these sorts of things out.[bighmmm]
Its a bit of a change from setting off the fire system by breaking a sprinkler head or punching an entrapment alarm in, just as they all head up to their bedroom suites.[bighmmm]

At the youth centre,breaking a sprinkler head sets off the deluge systems, it floods the whole block, an absolute PITA,as it wrecks the whole place.[bigsad]
They are starting to modify this system so it can only be manually turned on by a staff member.