C&G 2079 Training

[Grizzly]

Having recently taken the 2079 exam and practical.
With several of my colleagues.
We were all slightly shocked by the response of our very experienced trainer.
Basically when being questioned on charging technique of a Zeotropic (Blend) Refrigerant.
Where as Chiller Engineers we are taught to charge with Vapour ( throttle the liquid prior to it entering the system).
Until reaching a system pressure compatible with 0c.
Therefore eliminating the possibility of creating ice crystals within the condenser or evap.
Our instructor was having none of it
We have all discussed this before I know, and it's irrelevant for a lot of the guys!
But at least if you are informed of it's relevance, it can be applied when necessary.

Has anyone else come across this during training?
Grizzly

[Lman]

come on grizzly the trainer knows best dump all the liquid in and whalst your at it turn the water pumps off lol

[Grizzly]

come on grizzly the trainer knows best dump all the liquid in and whalst your at it turn the water pumps off lol

You been there too I guess?
Grizzly

[ptsac]

I suppose it could just be a misunderstanding. We still charge in the liquid state but allow to vaporise before entering the system, until as you say above oc saturated. However you would hope he could have realised that.

[Lman]

No he did mean dump it in as liquid as we told him we throttle it back to prevent icing. The reply was basically why would you want to do that use the vac to get as much liquid in as you can.

[monkey spanners]

So long as it leaves the bottle as a liquid it doesn't matter what state it enters the system, and as you say Grizzly it wants to be a vapour till the saturation (? i forget the propper terms ) temperature for the refrigerant is above the freezing point of what you is chilling.

And if you are putting the whole bottle in you can take it out as vapour also, as it'll get mixed up again in the system.

Jon

[Grizzly]

Hi Jon.
thanks for the input. as I say we have all discussed it before, it was just that Our instructor was not interested.
After all no-one is going to argue with their assessor are they.
Yet they are only human like the rest of us.
It's no big thing I was just wondering as to whether anyone else has experienced similar.

Thanks for the back-up Lman.
Grizzly

[Brian_UK]

I think also Grizzly that some people, your assessor eg, sometimes listen but don't hear what is being said.

He has to ensure that his trainees take liquid out of the bottle and that is what he will stick with.

If you add complications like doing it properly then you simply confuse the issue. Some people haven't grasped yet that you can use your manifold valves as throttling devices thereby splitting the phases at that point.

[taz24]

Having recently taken the 2079 exam and practical.
With several of my colleagues.
We were all slightly shocked by the response of our very experienced trainer.
Basically when being questioned on charging technique of a Zeotropic (Blend) Refrigerant.
Where as Chiller Engineers we are taught to charge with Vapour ( throttle the liquid prior to it entering the system).
Until reaching a system pressure compatible with 0c.
Therefore eliminating the possibility of creating ice crystals within the condenser or evap.
Our instructor was having none of it
We have all discussed this before I know, and it's irrelevant for a lot of the guys!
But at least if you are informed of it's relevance, it can be applied when necessary.

Has anyone else come across this during training?
Grizzly

Could it have been a misunderstanding.

I tell people to bomb charge the refrigerant in,
all of it in one go if possible but if the pressure equalises
then the refrigerant has to be bled in while the system is running.

On the assessment you have to demonstrate both liquid
charging to the system and bleeding the stuff in to a working system,
so is it possible the guy was just concerned with that more and lost
the point of your argument??

I know what you mean about questioning the assessor but they are only
human and don't know it all.

I know I don't

taz.

[Latte]

Something i thought was wierd. A question come up something like although cant remeber the exact wording "what should R410 gauges NOT have". The answer they were looking for was a sightglass, however on my next visit to NRS there on display was a Rothenburger display stand full of different gauges and the 410 one's DO HAVE sightglasses !!!!!!

Work that one out

[cadwaladr]

Something i thought was wierd. A question come up something like although cant remeber the exact wording "what should R410 gauges NOT have". The answer they were looking for was a sightglass, however on my next visit to NRS there on display was a Rothenburger display stand full of different gauges and the 410 one's DO HAVE sightglasses !!!!!!

Work that one out

yes heard that,mine have a sight glass you ask yourself do r410 systems have sight glass fitted?

[Brian_UK]

Something i thought was wierd. A question come up something like although cant remeber the exact wording "what should R410 gauges NOT have". The answer they were looking for was a sightglass, however on my next visit to NRS there on display was a Rothenburger display stand full of different gauges and the 410 one's DO HAVE sightglasses !!!!!!

Work that one out

That's mainly relating to people using their manifold set for pressure testing.

Yes, the manifold should take the test pressure but, is it worth the risk?