Fujitsu ARY60UUAK troubleshooting

[jester.ro]

Hello

Let me just start by saying i'm in no way a technician or able to repair an air conditioning unit, so be gentle please

Anyway, i have a Fujitsu ARY60UUAK that i use to cool a computer room. It's been installed 2 years ago, and it worked just fine until few days ago.

It works fine for a short time, but then the indoor unit just stops. The wired remote displays error (E:EE) and the only way to turn the unit back on is to cut the power and start it again.

After searching alot i found the way to display the engineering error codes on the wired remote, and the code is 0:0E, which seems to be "Outdoor high pressure abnormal".

Now the problem is the outdoor unit is not easily accesible, and not very visible either, but i can find a way to get near it to inspect it.

So my question is, before the technicians arrive to check it out, is there something i can do? What does "Outdoor high pressure abnormal" actually mean? could it be the fans and the coolers are clogged with dust and the unit is not getting enough cooling? i had a look at other outdoor units that are whithin reach, and noticed they're almost covered in a sort of dust/cotton-like blanket, probably from the poplar trees around, being spring and all.

Thank you for your time, i really hope you guys can give me a few pointers.

[nike123]

You are on right track. It could be clogged condenser fins and/or faulty fan.

[jester.ro]

managed to get to the outdoor unit with a vacuum cleaner and removed everything that was clogged on the fins.


What's weird is that the outdoor unit was in better shape than others, much cleaner and still misbehaved like that. For now the unit has been running for a fewhours without any problems, but i'm still waiting for the tech to have a look at it.

[jester.ro]

hey guys. i'm returning with the same problem it seems.

Cleaning the outdoor unit didn't really help apparently. The unit still stops from time to time, but i noticed it starts again by itself.

Now, when i first described my setup, i left out a detail that might be pretty important. The indoor unit is placed on the ceiling of 3'rd floor of a building, and the outdoor unit is placed at the level of 1'st floor floor. That would make the level difference about 7 meters, could that be a problem? The unit was installed by a proffesional team, but looking back at it, i don't know how professional they were, specially since i'm cureently looking for another company to fix my AC problems, since the first ones are nowhere to be found.

[nike123]

The indoor unit is placed on the ceiling of 3'rd floor of a building, and the outdoor unit is placed at the level of 1'st floor floor. That would make the level difference about 7 meters, could that be a problem?

No!
..................

[jester.ro]

thanks for the quick and definitive answer.

But then what does "Outdoor high pressure abnormal" reffer to? who's pressure is too high?

[Brian_UK]

But then what does "Outdoor high pressure abnormal" refer to? who's pressure is too high?

The heat that is removed from your indoor room is discharged by the outdoor unit during the cooling process.

If the outdoor coil, condenser, gets blocked by dust, debris or anything else then it is unable to get rid of that heat.

Refrigerants change their pressure in relation to their temperature so, the hotter the refrigerant the higher the pressure is. When that temperature/pressure rises towards a potential danger point the software within the unit shuts it down.

If the unit runs at high temperatures for too long then the lubricating oil can start breaking down and eventually the compressor will be killed.

Hence, keep it clean, both indoor and outdoor.

[jester.ro]

ok, so basically the outdoor unit cannot release the temperature in a timely manner, so it stops.

Problem is currently both units are pretty clean, the 2 big fans on the outdoor unit work fine, and the fins are not clogged by anything. What else should i check? Could be it that some sort of pressure sensor is broken? The unit has been running non-stop for about 2 years. Currently the outside temperature isn't very high (ambient), about 27-30 celsius. Last year, in the summer, the unit ran fine when there were 40+ celsius outside.

I've also noticed something else. The indoor unit has a pipe attached to it, that goes outside. I guess it's the pipe that lets condensed water go out, like i saw on other AC units. But the thing is that pipe is very dry, no drop of water comes out at the end. I'm not sure if that's normal .

[Brian_UK]

One problem with using 'regular' air conditioning units to cool computer rooms is that they are not designed for that type of duty.

When first started the unit will cool the room by cooling the moisture in the air which condenses on the surface of the indoor coil. This moisture then runs out of the unit via your drain pipe.

Now it seems that the unit has reached the limits of it's cooling ability as there is no more moisture in the room to cool down; as seen by your dry drain pipe.

The cooling cycle is now being switched on and off by the internal units freeze protection circuit because the coil is getting too cold because it is dry. If you can maintain the humidity level towards 50% then your cooling will improve.

Life was so much easier before computer rooms.

As an aside, not a complaint, although you vacuumed the outdoor coil there may still be a build up of dirt within the fins of the coil, a liquid spray cleaner is recommended to finish the job.

[jester.ro]

actually i just checked the indoor unit now, cleaning it even more. I was expecting that the fins of that coil would be cold, but they aren't. They're at room temperature(maybe a little colder, but they certainly don;t feel like any cooling liquid has run near them). It's true the unit has been mostly off cose of the above error, but i'm also guessing that a cooling fluid leak would have been represented by another error on the wired remote, right?

I'll try and look again at the outdoor unit tomorrow, to see if it can be cleaned even more.

But honestly this cleaning thing seems a little too much, i have other smaller units (4 x 24k btu fujitsu as well) that have absolutely no problem running in the same conditions. The only difference (apart from model of course) is that the outdoor units for them are much closer to the indoors (2 meters max).

[jester.ro]

unfortunately i cannot edit my post to add a question: where is the temperature sensor that checks if the is supposed to stop cooling the room? on the wired remote? on the indoor unit (saw a sensor-like thingie on the fins of the coil) ?

Considering this is definitely not a heavy-duty always-on kind of AC, would setting it to a higher temperature on the remote benefit it in the long run?

I have it set to 22 celsius now, and the room temperature rarely goes that low, usually is around 23-24.

The room isn't very big, it's 70 square meters and 2.6 meters high. It contains about 150 servers, inside 15 42U racks. The cooling consists of this 60k btu unit + 4 other 24k btu units.

Is there a calculator for the amount of BTU's required to cool a certain amount of wattage consumption?, maybe taking the room volume into consideration as well?

[back2space]

unfortunately i cannot edit my post to add a question: where is the temperature sensor that checks if the is supposed to stop cooling the room? on the wired remote? on the indoor unit (saw a sensor-like thingie on the fins of the coil) ?

Considering this is definitely not a heavy-duty always-on kind of AC, would setting it to a higher temperature on the remote benefit it in the long run?

I have it set to 22 celsius now, and the room temperature rarely goes that low, usually is around 23-24.

The room isn't very big, it's 70 square meters and 2.6 meters high. It contains about 150 servers, inside 15 42U racks. The cooling consists of this 60k btu unit + 4 other 24k btu units.

Is there a calculator for the amount of BTU's required to cool a certain amount of wattage consumption?, maybe taking the room volume into consideration as well?

What are your air on and air off temperatures from the indoor unit?

[bigor_2]

2 jester.ro
Pls visit to apc.com/prod_docs/results.cfm?class=wp&ISOCountryCode=ro and download documents WP-50 and WP-55.
These documents will help to find answers to your questions.
In due time they too have helped me.

[nike123]

You done what you can, now it is right time for calling service engineer.

[jester.ro]

oook, so the techs came today, they fixed all of the units.

regarding the fujitsu duct problem, they said it was something related to the wired remote, not sending the right signals to the outdoor unit. Anyway, after they worked on it, the unit ran fine for about 8 hours (previoulsy it was stopping every 10 minutes).

But now it's happening again. So after 8 hours of running well, it started stopping again, with the same error. So the techs have to come back on monday, but i really don;t understand. whatever they fixed, was temporary.

[bigor_2]

Duct type AC has the air filter?