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Every night since Friday,that’s a lot if you are also working the days.Quote:
Originally Posted by rick130
I am pretty sure there are legislative requirements in Qld in relation to breaks after doing call outs after hours.
If it’s not legislative in the industry we are in,then some companies may have their own rules.
I will try and find out.
Yes,duty of care comes into it as well.
Paul, I trust you donned your PPE to hose that condenser out. You could have got wet otherwise.[biggrin]
That one has caught a lot of Mechs/Techs (Tex Mex) out over the years & it was always one I had a shufti at usually before getting in deep.
But then I am Perfect, just like Trump says he is.[biggrin]
Even here at home I need to do it pre-- Xmas even though the air appears clean there can be a lot of small **** floating around. Thanks for the reminder though, with a forecast of 47c in the city it may need it since it has been a while since being done.
Have already refueled Fire Pump & Genny & test run them this morning as SA Power Networks reckon an outage is on the cards today. If that is all that happens we'll be happy.[bigsad]
Rick,Quote:
Originally Posted by scarry
Checked with a mate who works for a large commercial refrigeration contracter in QLD,so maybe not relevant?
They do ammonia as well.
His words were the award wording is tricky.
They are entitled to 10 hours rest after finishing a call out,but if required to work the next day before the 10 hours is up,they are paid double time.
Your situation may depend on how well you get on with your boss?
And as said,NSW maybe different,there are state and federal awards.
Point I was making (not too well...) is that 1234yf has been around- as an invention etc - for a long-ish time.
Mercedes (Daimler?) is being obstinate as they believe in CO2 , and are working on it. By themselves, it seems.
Naturally, this would not sit well with the US makers / patent owners of 'the Other Gas' if the Merc approach proves correct...
Anyway, its just another Flammable refrigerent gas, one HVAC guy I spoke to tells me the Flammability Class is "2.1" - what ever that is, but apparantly not "mildly flammable" as the 'US Patent owner' claims in some of its literature.
You're in a better position to interpret this :-
http://www.harpintl.com/downloads/pd...1234yf-clp.pdf and
https://www.boconline.co.uk/en/legac...7,tcm:10-90007
SOLSTICE YF REFRIGERANT (R-1234YF) MSDS | MsdsDigital.com | Search our SDS online database free | Material Safety Data Sheet
The parting words of the company who fixed a bus I picked up... 'R134a is fine, but doesn't work like R12 or the hydrocarbon ones when it gets REALLY hot' , like our 41+ degree days out here in WA
I think it also comes down to how well the systems are built.- Money.... if the gas ain't all that good, thent he hardware needs to be matched (bigger) to suit,
- Our Toyota Camry is a mobile refrigerator, the Magna is only "ok" , even with new compressor and gas. Both 134a.
But the old CM Valiant.... would give frostbite to the middle rear and front seat pax, no matter how much the road was melting! R12 of course.
Good luck to MB trying to get CO2 to work on a car.
I work with it on supermarkets and in transcritical systems (medium temp and low temp systems combined, vs the CO2/R134a cascades that were current until very recently) we see 90bar consistently in the high side.
That's 1300psi in old school terms.
I realise hydraulics see those sort of pressures, but it means no aluminum heat exchangers, the system I work on uses stainless steel headers and pipework on the high side, heavy gauge copper on the low side including the evaps.
There are big energy efficiencies with using CO2, as well as capital savings as the physical size of the plant is smaller, but the pressures make things 'interesting' and is very very easy to make the system a bomb if you aren't careful.
You need to be very careful not to trap liquid anywhere.
The rate of expansion with only a minor increase in temp is the scary part.
Stolen from another site.[bigsad]
https://www1.picturepush.com/photo/a...0/16224797.jpg
On another subject,
Auto air systems retrofitted from R12 to R134a never worked well in hot weather,mainly due to the condenser being to small for R134a.
Systems designed and fitted OEM, for R134a are usually fine,as they should be,its been used in auto air since 1995.
Discovery2,3,and 4 are a good example,their AC systems are fantastic,they will work extremely well even in temperatures of 45 degrees.
My weekend off and the phone rings at 4:15!!!!
The young tech on-site needed some advice.
Another failed coil on an EXV at the transcritical site.
Not sure what's going on there.
That's a bit scary.Quote:
Originally Posted by scarry
My initial thoughts when I read this was........ intermittent voltage spikes &/or sticking Sol. Valve armatures or poor electrical terminations but I'm sure you have considered these things Rick, but just recalling the "good olde days" when a Sol. coil was just a Sol. Coil regardless of the refrigerant. Not unless it is fighting a bit of abnormal high pressure from somewhere with Co2?Quote:
Originally Posted by rick130
Or even a crap/ substandard coil that is under-rated for it's duty?
Or do you think I've been breathing too much smoke? [bigsmile1]
These are actually an armature with two windings to drive the stepper open and closed, Des.
Unlike a TXV that uses a needle and seat, Electronic expansion valves are like a small poppet valve and orifice and drive open and closed in incremental steps, (usually several hundred) hence the name stepper valve.
The supply to the actual valve is via a 'driver' a fully programmable device that measures superheat via a thermistor, and suction pressure via a pressure transducer to maintain superheat.
We're losing one winding in the armature/coil, its going high resistance so the valve can only move one way.
As soon as the driver reads the high resistance it goes straight into error and stops.
I have a set of magnets to manually drive the valve open and closed, the yoing bloke is on his way back to my place to grab them so he can close the valve as I think it's lost its midpoint and isn't opening properly.
It thinks it's 100% open but isn't feeding, so he needs to manually close the valve and then plug the driver back into the coil/armature and I'm hoping it will then work.
I've talked him through the other checks, e.g. sensor and the transducer is ok as they use a common transducer for several valves.
It's easy to check too, check the module suction trans reading against the rack suction pressure trans back on the computer in the plant room
The poor bugger is doing some miles, this customer is 1.25 hours away, he was nearly home when he was called back, the case temp hadn't come down.
He needs a set of Carel magnets. [emoji6]