Long pipe setting on LG OUtdoor unit

[back2space]

Does anyone know what the Long Pipe setting on an LG outdoor unit does?

One of our pipe runs is at the max reccomended almost and we was wondering if we should use it.

[baycuclaudyu]

In a past I have problem with one LG split .The lenght of pipe was 16 meters all is on higher point .And after some times blink me and say I have an alarm.After I set to long pipe I dont have an alarm .

[VRVIII]

Does anyone know what the Long Pipe setting on an LG outdoor unit does?

One of our pipe runs is at the max reccomended almost and we was wondering if we should use it.

Hi,

I can’t say for definite but I suspect this will adjust the target evaporating and condesing temps due to the additional pressure drop caused by longer pipe runs.

[back2space]

One of our pipe runs is 24metres and the max pipe run per unit can not exceed 25metres... the other 2 units have a pipe run of 4 and 10 metres, would you say that I need to activate the long pipe run, even though only one is near the max.

Total pipe run for the entire system can not exceed 70 metres...

What would you suggest... I have tried both and not noticed any extra amps/wattage draw and seems to be have the same.

We are having an issue where the back room which is a 24metres piperun the coil temp doesnt seem to get high enough to be able to increase the fan speed to high when we only have that one unit demanding heat, if we have another unit demanding heat then the compressor ramps up increasing refrigerant temp so the unit in the backroom then switches to the fan speed we have selected.

Not sure what its issue is, we had all the refrigerant checked and leaks checked and firstly there was a leak on the system but everything is fine now.

Perhaps its the control strategy.

SOmeone said that the switch increases the compressor speed to increase the pressure in the system?

[back2space]

Hi,

I can’t say for definite but I suspect this will adjust the target evaporating and condesing temps due to the additional pressure drop caused by longer pipe runs.

Assuming this makes the outdoor unit work harder... meaning more wear and tear?

[back2space]

I believe the unit now has 100grams more than it needs as it should have 1300grams in and it has 1400grams in.

Not impressed as going to have to get them out again... more expense. The system is working ok now we have activated long pipe but if he says the charge can be detrimental or wear it out I dont want to run that risk.

Also not impressed that the original installers have not installed one of the units at the min 5 mtr pipe run... its 2metres!

Got this reply below from LG:

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Richard,

We are told that it increases the Compressor frequency, marginally.
Without a frequency meter I doubt whether it would be noticeable.

A 100g over-charge would be considered an excessive amount, and potentially detrimental to the operation of the equipment.
Also, the MINIMUM length to any indoor unit is 5m, so one unit is incorrectly piped.


If total charge value after calculation comes out positive (more refrigerant to be added), move the slide switch to long position.

Kind Regards,

Ken Macedo
Air Conditioning Hotline Supervisor

[back2space]

Hi,

I can’t say for definite but I suspect this will adjust the target evaporating and condesing temps due to the additional pressure drop caused by longer pipe runs.

Just changed it back to Normal Pipe Setting as getting very low air off temps and complaints of the draughts from the excessively low air off temps in cooling mode whilst it doesnt make any difference in heating mode (compressor ramped up higher anyway) in cooling mode the air off temps are about 11/12C whereas in Long pipe mode we get about 7/8 and complaints of draughts in the area so I guess it causes compressor to ramp up further in cooling mode and as you say VRVIII adjust the evaporating and condensing temps as longer pipe runs will cause duty drop. Due to the units being oversized anyway this is not a problem and we still have got plenty of cooling.