Thread: One for the fridgies

Des, you'd like the smarts of the electronic gear.
It all self diagnoses, and is pretty much spot on, or at the very least points you in the right direction.

While we had electronic expansion valves back in the eighties for AC, the modern ones are very good, just had a couple of Carel coils falling over on a new supermarket where we are providing warranty backup for the installer.

As Tote said, when you understand a control circuit and what it's trying to achieve you can generally nut something out, regardless of what it is.
And I keep telling the young blokes, keep it simple, go back to your basics, don't over complicate things or jump to conclusions, pick a starting point and methodically work through the system, don't jump around all over the place guessing.

And I keep telling the young blokes, keep it simple, go back to your basics, don't over complicate things or jump to conclusions, pick a starting point and methodically work through the system, don't jump around all over the place guessing.

Excellent advice indeed, Rick. Sort of like "First, fit your gauge set". "Eeerrr boss,what's a gauge set"

I know, I'm being facetious here now, which is not like me I realise?


Miniature Electronics certainly have improved our lives not only in Refrigeration & Photography etc but jeeeezuz a lot of it appears to be a tad overkill in some things & as Paul mentioned just because you can, or words to that effect.

Where the electronics bring people undone is when they rely on them instead of using their basic understanding of how things work.

We had a supermarket rack recently short of refrigerant.

The clients tech said no its not, it's not going into low liquid alarm.
Except all the sight glasses in the receiver were empty, the evaps he was working on in the big dairy room (they are just iced up!!) were only partial ice ups (bottom half) and the cool room next door was alarming and when you walked in you could hear the TX valves hissing thanks to starving of liquid.

But he didn't have an LL alarm so it was something else!

Thats' a good one Rick.

A hissing TEV is safely a good starting point not to mention MT Sight glasses let alone the partially iced coils. It hisses because it is passing vapour ffs.


Those sort of circumstances wouldn't need "electronics" to help him on his way. Just eyes & ears & maybe a kick up the arse.


Did you find the reason for the "buggered" electronics?

Those long hours can certainly be an absolute PITA,they can burn you out pretty easy.
I did 8 call outs one weekend last year,and i think i am a bit older than Rick
I am the same,an early morning call,say at 2.00am,and i can't get back to sleep,then its go again the next day.
And the other issue,the long hours are usually in summer,which compounds the tiredness,due to heat and humidity during the day,and the amount of work that time of the year.
Definitely a WH&S issue.
I think there are rules about having a set period of rest after call outs,but i didn't worry about it,i just kept going,as do the boys.

We recently had to go to a job,where the Daikin 20KW ducted unit had a fault code that said reversing valve fault.
The other contracter had replaced the valve twice,and the inverter board,then gave up.
The customer had had enough.

One of the boys went there,and it was a faulty sensor on the evaporater coil,not the reversing valve.Easy to diagnose,10 minutes max.
Get into the wall controller parameters,and the senser values are displayed,one is at -40 degrees.

This is where experience and careful diagnosis is needed.
The PCB looks at the faulty senser,and presumes the reversing valve is causing the fault.
Fault codes do not always give the correct fault.

Temper zone units are same,go out on LP,but no LP control,they work on using sensors to determine superheat.If its not correct,fault code will be LP.Often the real fault is blocked strainers in the accuraters,or the PCB is running the condenser fans to fast,therefore lowering the HP below what it should be,therefore increasing the system superheat.Nothing to do with Low Pressure.

I went to a Daikin refrigerated container last week,it is the most complicated refrigerated container on the planet,by a country mile
The site electrician had spent days trying to sort out numerous fault codes,with no luck.He was sure the electronic TX valve was shagged,we had replaced it a year ago.
Thorough hose of the condenser coil,hasn't tripped out for a week.

All fun and games.

Temper zone units are same,go out on LP,but no LP control,they work on using sensors to determine superheat.If its not correct,fault code will be LP.Often the real fault is blocked strainers in the accuraters,or the PCB is running the condenser fans to fast,therefore lowering the HP below what it should be,therefore increasing the system superheat.Nothing to do with Low Pressure.

Jayuz mate, just wondering if you could post some of this in English?

Originally Posted by Old Farang

Jayuz mate, just wondering if you could post some of this in English?

It wouldn't help.

Paul, I asked the question re stand down after long on call hours.
Stand down only applies to scheduled shifts, there is no legislative requirement, at least in NSW for a mandated break when 'on call'
Of course this doesn't override an employers duty of care.

And yep, I'm on another callout atm.
Every night since last Friday.