Water Drips/ Water Splashing out on indoor wall mount evaporator, VRF VRV problem

[rashVRF]

Hello there folks,

I have only recently joined the force as a service engineer.
Here in Malaysia it is quite hot and humid.
We have this problem with vrv/vrf system installed in a hotel.

When ac switched off, the indoor wall mount units feels cold when the evaporator is touched.
because the indoor units are not switched on, hence the blower isnot working, and if left for a long time, the evaporator gets cold enough and starts dripping on the louver.

out of the entire system, about 6~8 indoor wall mount units suffer bad leaks termed ac sweating.

the rooms have bout 75% humidity, due to that it makes the dripping quite bad.
We believe that the expansion valve at the indoor unit does not fully close and that is how
refrigerant seeps to the evaporator.

Solutions:
1. Some say install a dehumidifier
2. others recommend a heater and a thermostat control to deter condensation.

which of this can help with the problem?

*Bare in mind that if the indoor units are switched on always, we do not have a condensation problem on the evaporator, however this is a hotel and when guest checkout these units are
in individual rooms are left switched off long enough and start dripping.

do advice me folks...
Im trying to seek a cost effective/simple way to solve the prob, but unsure if dehumidifier etc would do the job.

[install monkey]

what make is your system-if mitsi then perform a reset and this will realign lev heads-also mitsi are problematic for lev heads detatching themselves from lev bodys

[rashVRF]

mines Fujitsu VRF.
When you say reset you mean reset power and restart the entire system ?
I have done that. hoping the indoor valve would sit at proper original position when unit power off.
however there might be some dirt stuck in the valve not allowing it to fully shut, as in very tiny gap so gas seeps through making the unit sweat after approx 6~10hrs power off!.

what are lev heads ?

*besides that if I can use a dehumidifier or somesort that would reduce humidity so help prevent the refrigerant from seeping into evaporator during unit power off would be great.

[install monkey]

lev heads are the indoor valves you have been referring to, if you stop all indoor units does the condenser still run? sticking/welded contactor. can you run the system in full heating to maybe flush the system?

[rashVRF]

If i stop all indoor units , the outdoor(condenser) does not run.

I have not tried heating to flush the system, perhaps that one solution and then monitor it.

I do not think there is a problem with the contactors.
we have an Inverter compressor and one constant compressor in each outdoor unit.

thanks for the replies mate...
helpful discussion...

[The Viking]

Hmmm,
How old is this system?
Was it properly commissioned?

My first check would be to:
Turn all indoor units OFF, then start just one of the indoor unit you got problem with. Start it in cooling, set at minimum temperature.
Leave the other indoor units turned off on their remotes, or the central controller, whatever you got.

-Does the running unit perform well?

If not you got an installation problem, where the system "speaks" to the wrong indoor unit.


Only after the system passed this test would I start taking things apart and that's when things gets complicated...

You mentioned that you were new to this game? Any chance that you could get a more experienced engineer in to help you with this?
VRV/VRFs are complicated and not easy to learn trouble shooting on...
Sorry

[install monkey]

morning viking-good to see your alive and kicking

[jumper]

Fan should keep going long enough to warm & dry evaporator.

[The Viking]

morning viking-good to see your alive and kicking

Thank you, just starting to wake up from my hibernation...

[chemi-cool]

Thank you, just starting to wake up from my hibernation...

Its about time, you got some people here seriously worried.
Welcome back.

[Grizzly]

Hmmm,
How old is this system?
Was it properly commissioned?

My first check would be to:
Turn all indoor units OFF, then start just one of the indoor unit you got problem with. Start it in cooling, set at minimum temperature.
Leave the other indoor units turned off on their remotes, or the central controller, whatever you got.

-Does the running unit perform well?

If not you got an installation problem, where the system "speaks" to the wrong indoor unit.


Only after the system passed this test would I start taking things apart and that's when things gets complicated...

You mentioned that you were new to this game? Any chance that you could get a more experienced engineer in to help you with this?
VRV/VRFs are complicated and not easy to learn trouble shooting on...
Sorry

Yes ditto.
Welcome back my friend.
Grizzly

[rashVRF]

system is approx 1 year old now or slightly short of a year.
we are only going to resume troubleshooting very soon to diagnose d prob.

the hotel is open to guest, they just try keep d rooms used, or atleast keep the indoor units wiped as n when it starts drippin (usually after more then 12hrs switched off).


It was commisioned by other engineers, im only recently taking over.
I hope to learn much and fast.

*to answer your question, yes the system corresponds to the correct indoor unit,
and it runs fine.
i have tried that during my previous visit.


thanks viking... you must be quite d veteran i presume ?
hehe salute


hoping to learn from u guys..
cooling is now my job!

[The Viking]

thanks viking... you must be quite d veteran i presume ?

Not a veteran I'm afraid, just old.


As you are looking at more than one indoor unit with the same fault, EEVs not closing, on a newish system, then there aren't many things that could cause it.

Something is stopping all those valves from shutting. If there were one valve after a year, yes, it could be a manufacturing fault on the valve but you are talking 6 to 8 valves here. Extremely unlikely that they all failed of their own.

My best guess, remember that I'm a couple of thousand miles away, is that this system has "grit" in it.
Most likely whoever installed it did so without using OFN when they did brazings.

Only way to tell is to cut a strainer out to have a look.

Quick fix- don't turn indoor units OFF, leave them ON, in fan only if needed.
But, this is likely to cause compressor failures.

Better fix(and expensive)- cut driers in to the suction lines just before each compressor and change these frequently until you got a clean system.

Best fix- using a flushing agent to flush the system and then replace the oil.
But this is complicated and timeconsuming/expensive.


Good luck, and don't forget the most important bit...

Let us know what you find.

[goshen]

Hi
if all else mentioned above fails,resort to setting all units that are stopped for a few hours,to come on and operate for a few minutes ,this however is a awkward solution .
lev's should not have a leak that big, to allow liquid rerigerant to accumalate and cause what you discribe.
good luck

[kanchi]

Pleasechargetoapproximately5%gas

[stufus]

Is the power to the indoor unit's being dropped via a card reader or something similar.
If so this could be the cause of your problem ,resulting in the LEV heads ending up put of sync with the control's
The control's will think the valve is closed when in fact it is 12/20/30% open causing evap to flood when unit is off as the valve can't drive closed if the power is off !!
When power is returned the unit will presume the valve is closed and the cycle will continue every time the power is dropped out so the problem gets progressively worse.
But as suggested above lack of OFN purging during installation is also a very likely cause of your symptoms.
Cheers
Stu

[a/c.nick]

some good advice on this thread. i was guessing the wiring do not match the pipe work but you say its all good. so sounds like it could be a dodgy install. will fujitsu cover the unit if a dryer is installed on a r410a system? flush system and recharge with dryer if allowed might be your cheapest bet

[rashVRF]

Pleasechargetoapproximately5%gas

What do you mean?

[rashVRF]

Is the power to the indoor unit's being dropped via a card reader or something similar.
If so this could be the cause of your problem ,resulting in the LEV heads ending up put of sync with the control's
The control's will think the valve is closed when in fact it is 12/20/30% open causing evap to flood when unit is off as the valve can't drive closed if the power is off !!
When power is returned the unit will presume the valve is closed and the cycle will continue every time the power is dropped out so the problem gets progressively worse.
But as suggested above lack of OFN purging during installation is also a very likely cause of your symptoms.
Cheers
Stu

Hmm, i would also like to give this a check, maybe turn off d effected indoors using remote not by card reader, then monitor temp after LEV during switched off state ~ can do somesort of a comparison wit another unit by switchin off (removing card reader).

Also likr what was previously mentioned, try heating to temp flush!
I will b visitng site by early Feb and would want to try these methods to futher diagnose d system... Thanks again guys, i will keep d thread further updated wit my findings.

Thanks for d suggestions.
Cheers

[stufus]

Turning off by the controller will not sort the problem until all the LEV's are reset as they will still be out of step and even with the controller they may not drive fully closed.
Cheers
Stu

[kanchi]

What do you mean?

I'm sorry
I waswrongin Englishtranslation.

I think
For a5%chargeVRV AC
LEVbadcase ofVRV VRF

[stufus]

Well that clears that up
Cheers
Stu

I'm sorry
I waswrongin Englishtranslation.

I think
For a5%chargeVRV AC
LEVbadcase ofVRV VRF

[benijoseph]

dear rash

It seems ur solenoid valve is faulty or might not be connected properly to the circuit that is the reason it is not shutting when unit is off, or system might be dirty inside.
I had a similar problem it was with four indoor unit, it was faulty solenoid valve it used to start leaking every year. finally we put a shut of valve in series, whenever unit is not in use! put off the valve!

regds.

[rashVRF]

Turning off by the controller will not sort the problem until all the LEV's are reset as they will still be out of step and even with the controller they may not drive fully closed.
Cheers
Stu

Best i can do is to turn off power wait for 30 seconds and back on, and wait... Keep doin that with the main power until the valve heads sits at proper position. Perhaps if i do that 5 times it wud help the lev find the original start position, correct? Otherwise how else to reset its position?

[goshen]

Hi
couldnt put it in better words!!
best regards

[stufus]

I'm not to sure Rash ,most manufacturers have a procedure for resetting their valves ,I'm not familiar with the Fujitsu procedure .
If the system has a reclaim mode which opens all valves for recovery you could try activate this and then cancel it which should drive all the valves closed.
Cheers
Stu

[Raisins78]

I was going to say the same thing as Stufus.
If the indoors are getting isolated by the card reader, then it can cause this (seen it before)
Re-wire one to constant power and turn it off with the remote only, this should power down the valve and shut it completely. if that doesnt fix it, then id be putting money on scale in the system from pipe brazing.

[MR T]

maybe gas not enought

[rashVRF]

maybe gas not enought

could lack of gas cause such an issue ?

[jdunc2301]

maybe gas not enought

Ahh the old "something isn't working blame the charge" ............

could lack of gas cause such an issue ?

I doubt it, i would make a bet that its the valves not closing off correctly

J

[Mrdaikin]

I would say that stufus has hit the nail on the head with this issue, something is stopping the operation of these units before the expansion device has driven into its closed position.

[Mrdaikin]

Rash, do you have model no of outdoor and indoor units??

[stufus]

It's not short of gas !!!
Your LEV's are out of step..
Ring Fujitsu for the vale reset procedure.
Even oxidisation would not cause this amount of valve issues ,(unless the pipe work was full of water during installation)
Cheers
Stu

could lack of gas cause such an issue ?

[jdunc2301]

What do you mean its not short of gas! It's always the gas!!!

J

It's not short of gas !!!
Your LEV's are out of step..
Ring Fujitsu for the vale reset procedure.
Even oxidisation would not cause this amount of valve issues ,(unless the pipe work was full of water during installation)
Cheers
Stu

[Mrdaikin]

I'm pretty sure on the AOY type outdoor unit, sw2-3 (on) is the electronic expansion valve initialization... however can't believe a system of this age would have that many valves out of sink without some external interference.