Re: LG Multisplit ongoing issue... slowly getting there I think!
UPDATE - LG Attended Yesterday:
Very friendly and knowledgeable chap... arrived at 8am.
The man connected a laptop, checked all sensors and found that 2 of the indoor units had loose connections on the board where the sensors connect. This could cause the unit to throw up an error code showing that the sensor was missing/shorted (never happened) or it would raise the resistance and give false readings back to the outdoor unit. He is to arrange replacement sensors to fix this.
Checking over the outdoor unit all sensors were ok on here... the outdoor air temp sensor had a plastic sheath round it and he said this will cause the sensor to be out as the air wont get to it (I disagree it may slow down reaction time by a few mins, nowt major though). So he cut that back so the sensor itself was in the air directly. The laptop showed that valves were operating etc and nothing stood out as not working properly but what the laptop doesnt show is if a valve is stuck as the system doesnt have sensors to show that a valve isnt operating correctly. I queried this but he said that it would stick out like a sore thumb on the readings. (dont think it would if it was a fraction not closing properly) EG laptop would show valve at 30pulses but what if it was at 20 or 40 pulses this would let too much or too little through.
He then did a calculation of the pipework and he says the unit is short of 220grams of gas. Strange as defrost cycles are few and far betweena and when it does the timed 5 hr oil return cycle there is never any ice built up on the outdoor unit. I queried if this would make much difference he was adament that it would cause an issue of poor heating. What I dont understand is that when the unit does a defrost or a oil return cycle and goes back into heating the heating performance and air offs are very good until the next cycle when they are back to being poor at 32C or so. Even putting it upto 30C they go up a by a few degrees but not much.
As soon as I turn another unit on the performance is good, we get good air off temps.
My engineer is going to come back and reclaim refrigerant through a drier and weigh it out to see whats in it as possibly short of refrigerant (why no freezing up of outdoor unit though?) if its short will need new refrigerant as I understand the gas is made up of different components.
Is there any logic in this email I sent to him this morning: What do you think:
"Very poor heating again this morning, only 32C air off in lounge (unit drawing 1.2kw), then the unit went into oil return mode (not defrost as its 6C outside and no frost on the coils) and 5 minutes later it is blowing air out at 40C and compressor drawing 1.6kw, is this a sign of it being undercharged such poor heating till it does oil return? Just funny how as soon as its done oil return I get good output. Also the fact that when two units are running means compressor is pumping harder to so if it is short of refrigerant how do I get better output when two are running as there is still the same amount of refrigerant isn’t there."
Let me know guys... hoping that it just a gas issue as its going to be an expensive winter when it gets really cold again (fan heaters etc)
Re: LG Multisplit ongoing issue... slowly getting there I think!
Hi Richard,
Sounds like you are getting somewhere now. Even though 220grams may not sound like much from my experience it can make a difference. I would suggest adding it. Also I would suggest selecting the 'LONG' pipe setting on the outdoor PCB. It may help by ramping the compressor up a few extra Hz. Just remember it is more likely that a system will go into defrost more often in temp > 0 deg C as there is more moisture in the air than < 0 deg C. Also as oil return and defrost perform similar functions this should aid in ensuring the system runs at its optimum capacity at the duration of the 2 functions hence why you are getting better air 'OFF' temps.
Re: LG Multisplit ongoing issue... slowly getting there I think!
The long pipe setting is already in use, haven't noticed any difference in performance at all. The whole thing is very poor. The guy was telling me not to be concerned with air offs but my opinion is if they are poor then that's the reason for low heating capacity.
Strange thing is when all 3 are running I am supposed to be getting less duty as the outdoor is over subscribed but I actually get better performance when all 3 are running than if just 1 is running which I am not supposed to get. So I would expect lower air offs when all three are running but no i get air offs of 47c versus 34c max when just one is running.
Nothing matches up with the data book at all.
Gonna be getting fan heaters out if this doesn't resolve it. I am hoping there isn't a leak, I noticed yesterday there was like an bluish film on top of the condensate that was coming out from under the unit. So hope the outdoor coil doesn't have a leak.
To get the gas recovered, purged with nitrogen etc, recharged is gonna cost me another £300. Could have had mitsi put in for what this has cost me.
Gutted :(
Quote:
Originally Posted by
Ross
Hi Richard,
Sounds like you are getting somewhere now. Even though 220grams may not sound like much from my experience it can make a difference. I would suggest adding it. Also I would suggest selecting the 'LONG' pipe setting on the outdoor PCB. It may help by ramping the compressor up a few extra Hz. Just remember it is more likely that a system will go into defrost more often in temp > 0 deg C as there is more moisture in the air than < 0 deg C. Also as oil return and defrost perform similar functions this should aid in ensuring the system runs at its optimum capacity at the duration of the 2 functions hence why you are getting better air 'OFF' temps.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Re: LG Multisplit ongoing issue... slowly getting there I think!
Paid £400 for reclaim, (no refrigerant loss whatsoever just slightly undercharged) so unit has exact refrirgerant weighed in as per LG.
However issues are still exactly the same. No change so I am not very happy.
WHen the system works it works very well however the next cycle on it may be very poor and air offs will be poor.
FOr example the other day when it was -2C outside an hour before I was getting air offs of 41C then an hour later air offs were 28C with no change if I put the set point upto 30C.
So I am back onto LG to see where they are going to take this next.
I still think its the EEV's as the outdoor unit main header pipe has higher temps than what gets to the indoor units. So its almost like the EEV's are not allowing enough gas through.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
DTLarca
What's the refrigerant?
Hi Mate
Refrigerant is R410a.
Re: LG Multisplit ongoing issue... slowly getting there I think!
With hand held instruments or with the lg software, cable and dongle were the subcool and superheat readings taken during operation before a defrost and then later after a defrost?
I'm just trying to work out where the refrigerant is during operation changes.
If it was R407C then internal fractionation would be a possibility. But with R410A there would be zero fractionation problems.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
DTLarca
With hand held instruments or with the lg software, cable and dongle were the subcool and superheat readings taken during operation before a defrost and then later after a defrost?
I'm just trying to work out where the refrigerant is during operation changes.
If it was R407C then internal fractionation would be a possibility. But with R410A there would be zero fractionation problems.
Yes they were and LG said all readings came back ok.
Thing is its not nessasarily after a defrost cycle this happens, could be the next on cycle that performance goes up or the next cycle performance may be poor.
Usually always good performance after a defrost cycle though.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
back2space
Yes they were and LG said all readings came back ok.
Thing is its not nessasarily after a defrost cycle this happens, could be the next on cycle that performance goes up or the next cycle performance may be poor.
Usually always good performance after a defrost cycle though.
Need to check actual inverter frequency at the different times then.
Most multi meters fail to register the hz coming off of inverters - instead we have to measure the volts onto the motor which increases with hz.
Just to eliminate any chance of a discrepancy between intended frequency and actual frequency.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
DTLarca
Need to check actual inverter frequency at the different times then.
Most multi meters fail to register the hz coming off of inverters - instead we have to measure the volts onto the motor which increases with hz.
Just to eliminate any chance of a discrepancy between intended frequency and actual frequency.
THis is something I checked as well... I have the unit connected to a energy meter and the current draw is the same (I measure in watts or volts) and it draws the same so the compressor is doing as it should. It just doesnt make anysense. Bang it upto 30C and you perhaps might get air off a few degrees warmer.
For example now justturned the unit on for today (been out all night) and getting air off of 43C and its 0.8C outside. Next on cycle may only get 32C air off but changing it to 30C witha return air off 21C it wouldnt increase that much.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Right guys bit of an update and I guess what appears to be a resolution.
No thanks to the engineers involved or lg's £500 a day service techs.
Today was getting air offs worse than when we had the -12c at night so I thought enough is enough I am going to take the covers off outside and look at the valves.
Spend an hour getting to the valves. End up on my hands and knees outside at -2c and notice that all the valve heads but one are not clipped onto the pipe.
They are loose and so the heads have never been seated properly so therefore appear to not have been driving the pin/screw inside. Eg when valve told to fully open it's only been able to open say halfway.
So I pushed all the heads down properly so they were clipped in place and then came back inside and checked air offs and getting nearlly 40c on the problem units.... Which is miles better than 25c I was getting this morning.
Cant believe that after I all I have spent it was something so simple and obvious. Why had my engineer never checked this. Same as LG!
It was getting to the stage where I was going to spend money on getting the valves replaced. I don't think they have ever been clipped on since one of the units was changed over as u really have to struggle at the floor level to see where they clip on.
Just testing it all now but so far so good.
Re: LG Multisplit ongoing issue... slowly getting there I think!
I think that you should stop spending your hard earned cash on various 'engineers' and LG.
Save it up and go on an AC Service Course, you know it makes sense. :D
Too, hope things do stay improved.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Update...
Havent been able to get on in a while but securing the EEV's back in place made no difference at all apart from the bedroom units coil now gets upto temperature quicker and will switch into desired fan speed after about 10minutes of operation!
Have emailed lg and no response as of yet! Useless!
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
back2space
Have emailed lg and no response as of yet! Useless!
And yet you still recommend them to others (bushyh), strange.
Re: LG Multisplit ongoing issue... slowly getting there I think!
Quote:
Originally Posted by
Brian_UK
And yet you still recommend them to others (bushyh), strange.
Multisplit units would be a no no at all, I would still reccomend the 1on1 splits as during the cold spell the system worked fine and plenty of heating its just this control strategy that seems to be odd.
Bushyt - lets face it anything is better than that calorex rubbish he has installed.