correct inverter refrigerant charge

How can you determine the accurat refrigerent charge in an inverter heat pump system?

Cheers

Sven

Get an experienced tech in to do it for you

< r t f m >

Recover and weigh.

you need an inverter checker to see if it is going the full 100% or for some machines 260% (Daikin) than use youre manifolds. ore you can recover, weigh and fill whit the correct amount.

Ice

you need to no the total lenth of the liquid line and then refer to the manufactures instalation instructions to calculate the extra charge and the base charge of the unit

Thanks for the replies.
It seems that recover and weigh is the easiest option
Can the inverter activity determined by the power consumption?

Cheers

Sven

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Originally Posted by Brian_UK

< r t f m >

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what does it mean

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Originally Posted by icecube51

you need an inverter checker to see if it is going the full 100% or for some machines 260% (Daikin) than use youre manifolds. ore you can recover, weigh and fill whit the correct amount.

Ice

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I can be wrong Ice but they're speeded up to 250 Hz so 500%, so they run at speeds of +/- 7000 RPM. That's why they brake so easily;):p

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Originally Posted by Peter_1

I can be wrong Ice but they're speeded up to 250 Hz so 500%, so they run at speeds of +/- 7000 RPM. That's why they brake so easily;):p

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No Peter, youre close, they speed up to 260Hz and 8800 rpm, before the engage the second compressor, than go down to 160 Hz. When the inverter reaches again 260 Hz and the std compressor 160 Hz they engage again an other, so now you now why the brake down so easy. When they are at full load the toptemps of the compressors reaches easy 90 °C to 110°C , so you now what happens to the oil at this stage.

Ice

Reclaim and weigh in + additional charge (For VRV)

make sure when you take messurments, the unit is at full load, this means, make sure every attacht unit is working at maximun capacity.

Ice

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Originally Posted by sumsor

what does that mean?

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http://en.wikipedia.org/wiki/RTFM

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Originally Posted by sachin230

what does it mean

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http://en.wikipedia.org/wiki/RTFM

Is that what it means? Not quite the answer I was hoping for.
I'm not aware that there's an explanaition in any of the single splits manuals.
For the city multis and the VRVs there is, but that's not what I was after.
I can't belive that there's no other way then recovering the charge and weigh, especially with the more expensive units like Mitsubishi and Daikin. Since the correct charge is the most important fact about the efficency of aircon units, why is there not a simple dip switch that gives you a fixed compressor output and valve settings? Surely that can't be that expensive!
Talking to another contractor, he told me that Daikin do a service and diagnostic tool for single splits, has anybody used this tool before?

Cheers

Sumsor:)

I don't see where is your problem. To reclaim and weigh 1kg of refrigerant (usual quantity in single split inverter) you need at most half hour.
To establish and measure all parameters which will tell you that unit is correctly charged ( and that is impossible for heat pump inverters, because of difference of charge in heating and cooling mode) you need more time.
Where is problem with easiest and safest (not to mention that any other system error cannot have influence on that result) way of establishing that charge is correct by weighing?

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Originally Posted by nike123

I don't see where is your problem. To reclaim and weigh 1kg of refrigerant (usual quantity in single split inverter) you need at most half hour.
To establish and measure all parameters which will tell you that unit is correctly charged ( and that is impossible for heat pump inverters, because of difference of charge in heating and cooling mode) you need more time.
Where is problem with easiest and safest (not to mention that any other system error cannot have influence on that result) way of establishing that charge is correct by weighing?

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Hi Nike123,

thanks for your reply.
I'm mainly working on city multi and VRV systems and the recovery takes a lot longer. Of course with the low amount it is a lot quicker to recover.

:o

Cheers

sumsor

Even with splits they have been critical charge since manufacturers went to rotary or swing compressors. Any Techs I knew that thought that they could charge a unit that take less than 1 kg of gas based on gauge pressure would usually find themselves returning to the job to reclaim and weigh in. Done plenty of tests charging units of pressure and then reclaiming to see how close I could get it. Always found I overcharged.

As for VRV there is ways to set the comp capacity however you can't control the air on temperatures in each different room or eev settings. Too many variables

VRV III does have have the auto charge function and refrigerant check function but not used in most countries.

With global warming and the push for more efficient units and goverment regulations I would say this will only get worse.

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Originally Posted by Crash Pilot

sumsor

Even with splits they have been critical charge since manufacturers went to rotary or swing compressors. Any Techs I knew that thought that they could charge a unit that take less than 1 kg of gas based on gauge pressure would usually find themselves returning to the job to reclaim and weigh in. Done plenty of tests charging units of pressure and then reclaiming to see how close I could get it. Always found I overcharged.

As for VRV there is ways to set the comp capacity however you can't control the air on temperatures in each different room or eev settings. Too many variables

VRV III does have have the auto charge function and refrigerant check function but not used in most countries.

With global warming and the push for more efficient units and goverment regulations I would say this will only get worse.

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Hi Crash Pilot,
very interesting, thanks mate.

sumsor

recover and weigh recoverd amount