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  1. #1
    Join Date
    Aug 2007
    Location
    Kansas
    Posts
    36

    Thumbs down Fujitsu Mini-split Problem Please Help!!

    I sold and installed a Fujitsu 36RCLX cassette type air conditioner in the center of the ceiling in a freshly remodeled board room. Indoor unit AUU36RCLX and outside unit AOU36RLX. Background: single story building, no windows, brick/cinder block construction, only north wall exposed to outside air, all other walls against controlled environments on other side. The board room was just remodeled, and it's dimensions are 38'X28' with a 9.5' ceiling. Condensing unit set on the roof, approx. 10 feet above cassette unit. Ran new 10 gauge copper circuit per NEC code and installed disconnect on roof. Pulled vacuum before releasing freon to 500 microns. The construction contractor installed a brand new drop ceiling before operation after initial install and insulated above drop ceiling with R-16.
    Here's the skinny.
    A/C worked fine 3 days after initial installation (as per factory included installation instructions), then went down on a 1b error code (high pressure sw). The ambiant temp was peaking around 90 F. One of my techs spent forever on the phone with Fujitsu tech support and they sent out a new control board we received 3 days later and then system ran for approx 24 hours before again going off again on a 1b error code. We blew out the indoor coil, cleaned the new condensor and powered back up. Stayed on line for around 4 hours, went off on compressor failure. Customer getting irritated, so I contacted sales rep and Fujitsu tech support, tryed more solutions (changed other parts and screwed around for about 8 more days changing parts as per their instruction) with same result, compressor would not start. Told sales rep to get out here with new unit and help find a fast viable solution. He came out, we spent an additional 3 hours on phone with Fujitsu tech support until he got extremely upset with them and he made the call to demo out existing outdoor unit and replace as per the installation instructions. We then installed a brand new outdoor unit. Installed new wiring harness to indoor unit and new line set as per their recommendation. Unit started and cooled board room to 72 degrees.....held temp for 3 days, then went down on 1b (high pressure sw)! We again called support, cleaned units again, powered down, started back up and would not stay on line for more than four hours at a time without going off on high pressure. Sales rep gave us the green light to change out the indoor unit, so we installed brand new indoor unit. System cooled like a champ for about 5 days, or until temps started hitting 100 degrees and then started into same 1b error code. Sales rep came back out today, we spent around 3 hours on phone with tech support today and they are trying to tell me that the operation parameters of the unit only go to 115 degrees F!!! The ambient temp on the roof this afternoon was 106 F and surface temp of the black tar roof was 122 F. They are now sending out a fan motor and a new control board again. The air going in the bottom side of the condensing coil was 112 F and the air going into top side was 107 F. I decided to paint the black tar roof around the condensing unit with snow white roof sealant and have knocked 7 degrees off surface temp directly in front of and around condensing unit.

    Has ANYONE had the same issue or does anyone have any suggestions regarding my situation. This has been a ridiculous situation and although we've sold and installed around 10 Fujitsu high wall systems without a single problem, I'm pretty sure that I'm done with this company. I purchased it from my Carrier sales rep and he has been wonderful in helping with the situation and feel he has went above and beyond, but he tryed to get a Fujitsu factory rep out to help remedy the problem and they weren't concerned with trying to help us. Please give me your insight. Thanks

  2. #2
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,774
    I use to like Fujitsu systems but I'm starting to take a second look. I've had a small server room down for more than 2 weeks now cause the 15 amp circuit breaker trips from time to time. No reason. No specific time. Sometimes it's once a summer..now it's every 2 to 3 weeks or so.

    Fujitisu would not help me until I was standing next to the unit..the roof is covered with yellow jackets and wasps. So got there real early one morning before the bees became active and ran all situations through tech support. No real answer from them cept the same old instruction manual talk.

    So I ordered a new power relay board thinging that after three years of running that the power relay has weakened and is putting the compressor into RLA tripping the circuit breaker. Have yet to receive the board but was told today it's in.

    Getting pretty dissapointed with them. Let me know what you found.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  3. #3
    Join Date
    Jul 2007
    Posts
    35
    Did you have the same error code (1b) at every failure? The 1b actually indicated an outdoor fan problem; it would be very strange if you have the same error every time, even after the change out.

  4. #4
    Join Date
    Aug 2007
    Location
    Kansas
    Posts
    36
    No, we had several different error codes in total, just can't remember what the error code was for the compressor failure off the top of my head. The 1b error code was the most recurring, and we had a 16 error code also 3-4 times which if not mistaken is the indoor coil dirty. Not at all impressed with Fujitsu or the way they stand behind their products.

  5. #5
    Join Date
    Jul 2007
    Posts
    35
    Just so I understand correctly, when you replaced the outdoor unit, tech support told you to weigh in more refrigerant? The pre-charged refrigerant should be more than enough for the 10' lineset in this installation. The extreme hot ambient air on the roof probably made the whole setup very unforgiving if the charge was not optimal. (They -Fujitsu- do have a design limit of 115 F outdoor for the cooling mode.)

    I would also suggest writing down the error code in a log with the related outdoor temp to help with the troubleshooting.

  6. #6
    Join Date
    Aug 2007
    Location
    Kansas
    Posts
    36
    I'm sorry, I didn't type that correctly, the charge we weighed in was after recovering the initial charge on the first unit and prior to the first unit's compressor failing. The pump down function would not work, and the guy at tech support wanted to make sure the charge was correct before proceeding. My fault for typing that wrong (i will edit error). My tech and sales rep have kept good record of everything that has went on, and Fujitsu has record of everything that has went on with tech support. ALSO: FYI, the minimum length of line set allowed via tech support is 16 feet, and the initial line set was shortened during installation and ended up 14' 9" (only could of made an oz or two differance in charge!). So that is why we went ahead and replaced the first line set and wiring harness, with a new full length line set and new wiring harness as per tech supports directions. The reason I'm on here is to try and figure out a solution, my customer is upset and the unit will currently run for long enough at a time to cool the room down to temp, it just trips out on a 1b error code after 1-4 hours of operation, so I've been going by a couple times a day trying to keep them cool by resetting system. Very frustrating to say the least. Live and Learn. I just can't imagine that I'm the only one in the world that has one of these on a tar roof? And you would think if the application was an issue, they would have been up front about avoiding situations like the present? I'm just trying to find a solution and was hoping with all of the knowledge here that someone might have faced a similar issue or the same poor resolve from Fujitsu. The best thing about it is the fact there is a old Rheem 10 seer on the same roof that has been running like a champ about 60 feet away, and the customer is letting me know all about it! LOL! Kansas is not the hottest place in the world!

  7. #7
    Join Date
    Sep 2004
    Location
    Newbury Berkshire
    Posts
    490
    Is it windy on the roof as occasionally these systems suffer when over exposed...

    Cheers

    Richard

    P.s Post some pics please that always helps;-)

  8. #8
    Join Date
    Jul 2002
    Location
    Slacking off right now
    Posts
    7,546
    lineset insulated seperatly? liquid and suction? ( I have seen some insultated together)

    correct wires between evap and cond? terminals?

    no joins in wires?

    I recomend raising the unit up a bit higher from the roof to reduce the radiant heat from affecting the condensor - I also recomend installign a bigger sheet of the pink- blue styrene sheets under the unit

    I don't buy rth 115z limit fujitisu units work all over the world and soem areas are hotter than 115

    I recomened checking the wires between the evap and the cont.

    there is a procedure to set these up for short linesets and the factory reps know this - find a factory rep that will work with you
    www.vetopropac.com - The best tool bags on the market - The offical tool bag of choice by techs everywhere

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  9. #9
    Join Date
    Aug 2007
    Location
    Kansas
    Posts
    36
    Yes, line set insulated both suction and liquid. We are not only using Fujitsu wiring harness, we have not only checked the connections, we replaced the original wiring harness when we replaced the line set just to make sure that wasn't an issue! I thought about raising it up off the roof as well, just hate to try much more without knowing it will fix the problem. I'll try to get some pics and post tomarrow. Sales rep says text book install, as he assisted on the second install. As far as the wind question, the unit should get plenty of airflow, but possibly limited when wind is blowing from the south. Good point and both good ideas. Thanks.

    Oh, BTW, we can't get a factory rep out here, and we are getting exact same results with long line set that we did with the short one. It did stay on line for about 6 hours today, so we are obviously looking at an ambient temp problem. Do any of you know how the high temp sensor works or where it is located? Is it using digital current draw on compressor or is there an actual sensor to shut unit down at 115 F?

  10. #10
    Join Date
    Mar 2007
    Location
    NW AR
    Posts
    2,478
    I changed a compressor in one recently. the hack that installed and had been working on it had a low suction so he kept pumping freon in it. Turns out the little crappy driers they put on them was restricted. After the compressor burnt up it clogged it completely and i mean 100% clogged. I evacuated the system(so i thought) and only got about 2 lbs.out of it. Cut suction line, all good. Cut discharge line and swooosh. i bet it had a total of 12 lbs of freon packed in the condensor. Capacity was only like 4.6. Comp. valve and clogged drier was holding the freon. Problem with the junkers is there is no high press. port on them.

    Anyway about your advice.
    1. I would braze a saddle piercing valve on the liquid line. Someone on here the other day said their is no liquid line..BS. Braze it to the line right before the filter drier. Its a little hard to get to (youll have to remove the side panel) but worth it to see what your head is doing.
    2. Not to doubt you but are you sure you got 500 microns? The evac on these takes much longer because your pump has to evacuate the entire condensor through the little cap tube.
    3. These units are easy to overcharge. Weigh it in a pound short and adjust from there.

    I replace the retarded little driers they put on them with standard ones.

    I said my piece. I feel a little better but still hate the pieces of !@#$. Dang gooks.
    Last edited by ar_hvac_man; 08-16-2007 at 05:35 PM.

  11. #11
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,774
    Replaced the power board on the one I'm having problems with today. Customer support was no help at all. And getting to the circuit boards is a tremendous amount of work!

    I'd give customer support a D minus. But I bet just about all the mini-splits are pretty well the same. You just install them and hope they never have a problem, especially as you are experiencing.

    Keep the story going as I would like to know what happens including customer support. I have a customer who wants two of them now and I've asked him to hold off till I find out if my problem went away.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  12. #12
    Join Date
    Jul 2002
    Location
    Slacking off right now
    Posts
    7,546
    I can only add to try and find a training course on these and put the full court press on the instructor for an answer
    www.vetopropac.com - The best tool bags on the market - The offical tool bag of choice by techs everywhere

    Arguing with some people is like wrestling a pig - eventually you realise the pig actually enjoys it

    Gonads serve a useful purpose but are no substitute for brains

  13. #13
    ha a similar problem with the same unit. not cooling, not running , blowing the fuse on the board, after much headache narrowed it down to the outdoor fan changed that out and its been good since

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