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  1. #1
    Join Date
    Mar 2007
    Location
    MD, USA
    Posts
    47

    dcm-500 squealing like a banshee

    Over the past 2 weeks we have had two calls to 2 seperate ice machines both of the dcm on the counter hoshizaki nugget machines.
    Both units will make ice as normal for approx 20 or 25 mins
    then will start to make a high pitch squealing noise.
    which is definately coming from where the ice is forced through from the bottom.
    OK spoke to factory about one of the machines my boss took care of the other.
    Factory suggested cleaning machine to remove calcium build up, and or replacing the TXV they believe that the TXV could well be freezing the ice too much making it to hard hence the squealing noise.
    Well my colleague went yesterday to change the TXV on the dcm 500 replaced it and the same noise would occur(high pitched squeal) so he cleaned the machine filling the drum with water and ice machine cleaner jumped the auger motor and allowed it to run hopefully cleaning it enough. Allowed to run for about half of an hour drained machine and fired it back up with the same high pitched squeal again occuring.
    I havent been back to the other machine yet since we havent resolved this one yet, my boss seems to thinkits a possible floor with the ice machines.
    Any ideas would be much appreciated anyone had the same problem.
    thank you
    If you can't be goodlooking at least be handy

  2. #2
    Join Date
    Apr 2001
    Posts
    669
    I saw the same problem about 10 years ago. I was told the same thing Hoshizaki told you except there is a extra step that's not in the cleaning instructions. In the extra step you need to pinch off the rubber tube that feeds water to the evaporator then pour the cleaning solution over the extruding head until it is full. This will will help remove the scale from the extruding. I believe that scale build-up on the extruding head is what's causing that high-pitch noise.



    Jabs

  3. #3
    Join Date
    Mar 2007
    Location
    wedged in freezer shelf
    Posts
    6,576
    Also make ice with the cleaning solution after it's done soak'n

  4. #4
    Join Date
    Aug 2009
    Location
    phoenix AZ
    Posts
    7
    Quote Originally Posted by HvacTommo View Post
    Over the past 2 weeks we have had two calls to 2 seperate ice machines both of the dcm on the counter hoshizaki nugget machines.
    Both units will make ice as normal for approx 20 or 25 mins
    then will start to make a high pitch squealing noise.
    which is definately coming from where the ice is forced through from the bottom.
    OK spoke to factory about one of the machines my boss took care of the other.
    Factory suggested cleaning machine to remove calcium build up, and or replacing the TXV they believe that the TXV could well be freezing the ice too much making it to hard hence the squealing noise.
    Well my colleague went yesterday to change the TXV on the dcm 500 replaced it and the same noise would occur(high pitched squeal) so he cleaned the machine filling the drum with water and ice machine cleaner jumped the auger motor and allowed it to run hopefully cleaning it enough. Allowed to run for about half of an hour drained machine and fired it back up with the same high pitched squeal again occuring.
    I havent been back to the other machine yet since we havent resolved this one yet, my boss seems to thinkits a possible floor with the ice machines.
    Any ideas would be much appreciated anyone had the same problem.
    thank you
    I also have this problem with the scotsman nugget machines. 9 out of 10 times you just need to clean the machine. When I have this problem I fully disassemble the head and the auger. I give it a good scrub down with a soft bristle brush and cleaner. I also grease the thrust bearing on the head and check the auger for any damage. On the scotsman machines after i clean them the auger motor amp draw drops by .4 to .5 amps. It,s amazing how much calcium can wreck a machine.

  5. #5
    Join Date
    Apr 2001
    Posts
    669
    Quote Originally Posted by AZreferguy View Post
    On the scotsman machines after i clean them the auger motor amp draw drops by .4 to .5 amps. It,s amazing how much calcium can wreck a machine.


    Calcium is what kills flaker gear boxes too.


    The last time I cleaned scale/calcium from ice machine/flaker.
    Jabs

  6. #6
    Join Date
    Jul 2012
    Location
    Nampa, ID
    Posts
    5
    Also, make sure to use Hoshizaki's bearing check tool (basically a paperclip that's to their specs). If any water gets in there and starts to freeze, it'll cause an issue as well.

  7. #7
    Join Date
    Jun 2009
    Location
    DFW, TX
    Posts
    645
    Quote Originally Posted by Jabarco View Post
    I saw the same problem about 10 years ago. I was told the same thing Hoshizaki told you except there is a extra step that's not in the cleaning instructions. In the extra step you need to pinch off the rubber tube that feeds water to the evaporator then pour the cleaning solution over the extruding head until it is full. This will will help remove the scale from the extruding. I believe that scale build-up on the extruding head is what's causing that high-pitch noise.
    +1 Good advice. They told me the same thing!

    Also, I worked on several of these flakers, and in my experience, the top bearings don't last long at all. It's not really even a bearing, just like a black stuff that loves to break apart. I bet if you disassemble the extruding head and look at that black bearing inside it, you will see some wear. And anytime I went to replace the bearings on a noisy DCM-500, I pull it apart and look at the evaporator and half the time it's all scored and basically they need a whole new machine. Once on a giant F-1500 flaker or something like that, customer complained of squealing noise, and I cleaned it just as described by Jabarco. Pinch off the hose, fill it with HOT water and descaler to cover extruding head, then disable compressor and let the gearbox run while it soaks. Drain out, restarted and they haven't called back so I'm pretty sure it fixed the issue. Good luck, you will need a metric allen wrench to take it apart if you really want to take it apart, but I would also try cleaning it first too.

  8. #8
    Join Date
    Dec 2010
    Location
    Savannah Ga.
    Posts
    41
    I agree.....clean it first....I don't believe too much in the "dump in cleaner and run the auger a while" type of cleaning. Pull it apart and clean/inspect it. It's not too hard to do. Sure it takes a little more time but when done, you can go home and sleep soundly knowing it's nice and clean! While in there, look at upper and lower bearings for signs of wear or breakage. Usually you can re-assemble with same bearings. Also use Hoshi. bearing check gauge to check clearance between auger shaft and bearing like previously posted.

    One other thing....if after a good thorough cleaning, she still squeaks, add a service port tap in between the TXV and evap inlet..... take pressure readings from before and after the evap. (use tap just installed and normal suction tap at comp)..... You're looking for the amount of pressure drop through the evap... 0 to 4 psi drop could be considered normal.... if the evap. is causing the squeak, you'll see a much higher difference in pressure, sometimes as much as 30 to 40 psi, but more commonly, 10 to 25 psi. What causes this is the copper tube that is wrapped around the evap. barrel somehow gets water trapped between itself and the barrel or an adjacent tube, and the water freezes and pinches the tube closed! I've seen some pinched so badly you wouldn't think it would flow at all! Once you find one and replace it, keep the old one and cut it apart and you'll see it! These days we see maybe 8 or 10 of these a year. Good luck!

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