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  • Manitowoc SD0502A  Ice Machine Troubleshooting?

  • guest

    Member
    July 21, 2019 at 12:00 am

     I have a Manitowoc SD0502A ice machine. It stopped producing Ice and after inspection of the machine I discovered that the silver round capacitor below the control board was bulging. I replaced the capacitor. After Moving the toggle switch to On position The machine starts its normal path to ice production,it will turn on, water curtain works and the compressor and condenser fan engage. The condenser fan will cycle off after about 7 minutes while the compressor remains running. The compressor shuts off about 8 minutes later and is really hot to  touch. No ice  is on the ice plate as  while it was running the water dripping over the ice plate did not fell cold enough to form ice cubes. What should I do next or what should I check? Shoudln`t the fan remain on so it cools the compressor?

  • fixbear

    Member
    July 21, 2019 at 12:54 pm

    The fan cycles with head pressure.  Does the suction side of the compressor feel cold?  What is the bottom of the condenser side feel like?  Does the top evaporator line from the TXV and hot gas valve feel hot or cold? 

     

    If you have a clamp on ammeter, monitor the compressor amps.  You may be having a no start condition that pops the thermal safety.  That requires a licensed tech to fix.  You never said whether it was the start cap or the run cap that failed.  Usually they do not bulge unless some power factor caused it like overload or surge.  Or start relay problem.

     

    Make sure you let us know which compressor you have. The Danfoss (Secore SC’s) have a know field problem with start, run after going off warranty due to the lube system having to pump oil to the top.

  • chefhenryclay

    Member
    July 21, 2019 at 3:11 pm

    I replaced the the run capacitor because the old one had a bulge in it. The compressor is a DanfossSC18MLX3. The bottom copper tubing coming out of the compressor is hot. The top copper tubing coming out of the compressor is not cold maybe a little warm. The condenser side where the copper tubing is warm. I do notice a water drip coming from the water inlet connection to the blue solenoid. You lost me on the location of the TVX?

  • chefhenryclay

    Member
    July 22, 2019 at 9:14 am

    After reading the manual I figure it is one of these that is causing no ice production………

    Electrical System

    1. Improper voltage (low)  

    2. Water inlet valve failure

    3. Compressor failure / start component failure page 146

    Refrigeration System

    1. Low on Refrigerant

    2. Starving TXV

    3. Head Pressure Control Valve stuck in Bypass

    4. Harvest valve leaking through or stuck open

    5 Inefficient compressor

  • fixbear

    Member
    July 22, 2019 at 10:05 am

    a TXV is the thermostatic expansion valve that controls the refrigerant to the evaporator. It’s in the top of the compressor compartment behind the evaporator   It will be wrapped with insulation, have a capillary tube with a bulb attached to the tail coil of the evaporator and a diaphragm chamber at the top of the valve.  The outlet side of the valve is what defines the low side of the system. The pressure drop is where the refrigerant starts to boil and absorb heat. This line should be freezing at that point.  Now there is a tee in that line that goes to the Hot gas bypass valve. (solenoid type valve)  that comes directly from the compressor discharge line.  It is to warm the evaporator during harvest.. If You feel the line near the tee both upstream of the hot gas valve and down stream toward the evaporator you should not feel heat, but cold.  If you feel heat,  it means the hot gas valve is leaking or open.  Be aware, that the machine has to go thru the whole stat up sequence before going into freeze cycle. During that period the harvest/hot gas valve will be energized.  This takes a full 55 seconds.  100 seconds before the water pump starts for pre chill of the plate..

     

    chefhenryclay wrote:

     

    . I do notice a water drip coming from the water inlet connection to the blue solenoid.

    Is the water drip going into the evaporator sump?  if so it may be adding enough heat to prevent icemaking.

     

    As long as you are certain that the compressor is running,  Start by cleaning the machine with Manitowoc ice machine cleaner. Follow the instructions in this manual; https://www.partstown.com/modelManual/MAN-S-Series_sm.pdf

    or this one; https://www.partstown.com/modelManual/MAN-S-Series_iom.pdf 

    Now let it run till it shuts down. Page 65 of the service manual tells you how to read the codes after shutdown.

     

    On page 97 of the first manual is the operational analysis table we use for troubleshooting.  It also has a complete explanation of the ice cycle

     

    Being you are in LA, That’s why you have the Danfoss/Secop compressor.  They are the preferred one for marine use due to the pump in the top. Prevents oil slugging,  As long as you have not heard any squeaking at start up or excessive noise during load, the lube system is probably OK.  Danfoss was near bankrupt about 6 years ago and shut down the plant that made their compressors in Czechoslovakia losing 3200 jobs. They sold to Secop in China now.  And the early ones out were a real problem. Especially in the 3 door reach in freezers sold under several brands.  I never saw a Danfoss in a ice machine in my area.

  • chefhenryclay

    Member
    July 22, 2019 at 3:13 pm

    Just to clarify, I am attaching a picture of the TXV and it is cold to the touch all around the T. The inlet connection water drip is not leaking into the evaporator sump.  I do see a quick SL1 red light flash on the control board upon start up right after I move the toggle switch to ice.

    I am going to let the machine run awhile but the compressor still clicks off after getting really hot.

  • chefhenryclay

    Member
    July 22, 2019 at 4:51 pm
    1. Refrigeration System Start-Up

    The remote condenser fan motor starts at the same time the compressor starts and remains on throughout the entire Freeze and Harvest Sequences.

    The remote condenser fan motor does not remain on throughout the entire freeze harvest sequences.

     

    I am presently in this mode…..

    Safety Limit Stand-By Mode: The first time a safety limit shut down occurs, (three consecutive long freeze or harvest cycles) the ice machine will turn off for 60 minutes (Stand-By Mode). During the Stand-By Mode the harvest light will be flashing continuously and a safety limit indication can be viewed. After 60 minutes the ice machine will automatically restart to see if the problem re-occurs. If the same safety limit is reached a second time (three more consecutive long freeze or harvest cycles) the ice machine will initiate a safety limit shut down and remain off until it is manually restarted. During a safety limit shut down the harvest light will be flashing continuously

  • fixbear

    Member
    July 23, 2019 at 8:48 am

    Ok, now we are getting somewhere.  you said; “I am going to let the machine run awhile but the compressor still clicks off after getting really hot”. So the compressor is in overload.  Either the fan is not up to speed, or the condenser is plugged up and no air is moving.  This causes a high head pressure and temperature. 

     

    Alternately the run capacitor is the wrong value or the start relay is not dropping out. It is voltage sensitive.  Make sure to test the supply voltage under load in case you have a high resistance due to wiring size or connections. 

    What voltage  is this machine..

  • chefhenryclay

    Member
    July 23, 2019 at 1:01 pm

    The machine is 115 v. I let the machine run overnight and came in this morning with a continuous red flashing SL1 light on the control board. I cleaned the condenser really good. The fan does spin freely when turned by hand, no resistance. Can the fan motor be bad even if it doesn`t feel hot after running?

    What is strapped to the fan motor? it is rusty on the outside

  • chefhenryclay

    Member
    July 23, 2019 at 1:15 pm

    I turned the machine back on and the compressor started right up but the condenser fan started about 60 seconds later and ran for a minute then cut off. I did see a spark and heard a loud click from the start relay right before the compressor went on. 

     the compressor is in overload now

  • chefhenryclay

    Member
    July 23, 2019 at 1:28 pm

    Could the Fan Motor Run Capacitor be bad? If so ,I did see under notes in the parts manual  that it is no longer available.

  • chefhenryclay

    Member
    July 23, 2019 at 2:22 pm

    I saw this video about the fan cycle switch and it is a common problem on Manitowoc. I am confused as to how he bypassed the fan cycle switch in order to make sure the fan is good?

    https://www.youtube.com/watch?v=DBJAoFsbCKE

  • fixbear

    Member
    July 23, 2019 at 6:38 pm

    your compressor is running in a overload condition.  The question is why. Often the condenser gets loaded with grease in a kitchen.  Not on the outside, but between the fins inside the coils.  So is there a adequet amount of air moving thruogh coiul?   The other possible is a tight bearing in the compressor, or wrong run capaciance for motor design and load.  The latter is something you need a qualified tech to find and fix.  It may even mean a new compressor if a winding or bearing inside the compressor is bad.

     

    Normally a 500 pound machine will be 230 volt.  Your looking at 20 amps to run a 115 machine. That means the wiring has to be 10 gauge, and good25 amp  breaker  breaker..

  • fixbear

    Member
    July 23, 2019 at 7:31 pm

    It’s a PSC motor.  If it starts during the boot/test section, it’s fine.  Make sure what you are reading is for the single evaporator, air cooled 5oo lb machine.  The service manual covers all machines  That’s why we generally only refer techs to it.  I wanted you to be able to understand the control system and how it worked. 

     

    To troubleshoot a ice machine,  one has to have a good DVOM,  clamp on ammeter, and digital thermometer.  And know how to use them.  By ohming out the motor windings and checking the load curent and voltage we can determine what is happening inside the compressor.  We know that your motor overload has been tripping.   The question is why.  You say the the condenser has air flow.  So now we have to look at the compressor electrical.  Does it have the correct voltage?  Is the run current below full load amps  (on the compressor label as FLA)   Do the winding’s ohm out correctly?   Is the start relay and capacitors to spec.

     

    If you do not have this equipment,  or the knowledge to us it,  You will be farther ahead calling a ice machine tech for this.  Unfortunately, It sounds to me as you have a compressor problem that will need a tech to solve.

  • chefhenryclay

    Member
    July 23, 2019 at 9:50 pm

    I will clean the unit between the fins inside the condenser coils I did a start in service mode all control board lights energized and then it started up normal and then the compressor overloaded. 

     I ordered a Manitowok motor run capacitor, maybe the Jard brand doesn`t function properly on this machine?
  • chefhenryclay

    Member
    July 24, 2019 at 3:26 pm

    I bypassed the fan cycle switch with jumper wires and the condenser fan now stays on. The compressor does not overload but there isn`t any ice formation. The water is cold running over the ice plate.   What could it be? No suction to form Ice? 

  • olivero

    Member
    July 24, 2019 at 5:23 pm

    Alright buddy.

     

    Listen e’re.

     

    The reason your compressor is going off is either A, High head pressure or B, High temperature, C High amperage

     

    High head can be caused by high temperature and vice versa. Hermetic compressors rely on the cold gas to cool it down, in order for the cold gas to exist, heat has to be removed from it which occurs in the condenser. There’s an evaporator (where the ice get’s made) and a condenser (where the big fan is, the thing strapped to it is a run cap or a start capacitor if it’s single phase).

     

    Now, there’s normally a switch which monitors head pressure and turns the fan on and off as it goes along it’s a common tool across the boards. SO If it’s bypassed and the fan stays on that might just mean that you have a leak, honestly it sounds like there’s not enough refrigerant to go around.

     

    A, your compressor is overheating, most likely due to insufficient cooling from the suction gas, due to an insufficient amount of suction gas which is due to a leak.

     

    B, your fan switch is not cycling the fan motor, probably due to the head being low due to a leak. Otherwise, if there was a restriction or the TXV was starving the evap, your head would run high and the fan would remain on. 

     

    C, There’s no ice on the plate which if anything, there should be ice on the plate if there’s refrigerant in the system and the fan stays on, that head pressure should be fine.

     

    D, if the TXV wasn’t working and was starving the evap, your head would run high IF there was a sufficient charge as all that refrigerant would be pumped against a wall but not going anywhere. If that was the case, the fan would remain on as your switch would detect the high head and cycle it on. 

     

    E, Low head and Low suction are normally a dead give away of a leak.

     

    Now you don’t strike me as a refrigeration technician so I doubt you can check it, but that’s what it sounds like AND DO NOT try to charge it if you don’t have a gauges and aren’t EPA, these units are critically charged, 1 oz too much or too little can make it or break it.

     

    Now let’s say it’s not what I said above,

     

    It could be the start relay not cutting the start cap out causing your compressor to run while overamping, effectively overheating it as well, a simple amp meter would tell you if that’s the case. I’ve never seen a compressor run for 8 minutes with the start capacitor still engaged though, the overload will catch it long before.

     

    So most likely, it’s A, B, C, D or E

     

    So do me a favor and feel the larger of the copper tubes coming back to the compressor, is it warm or cold?

     

    This unit probably has a hot gas defrost/harvest mechanism, that’ll be a solenoid valve on a non-insulated copper line. If it’s insulated it’s the suction/cold line. If it’s not insulated it’s the liquid/hot line. Feel both sides of the line with the solenoid valve, are they both the same temperature during cooling?, if so, the valve may be stuck open.

     

    Let us know.

  • chefhenryclay

    Member
    July 24, 2019 at 9:55 pm

    “feel the larger of the copper tubes coming back to the compressor, is it warm or cold?” It is not cold but its not hot

    The small un-insulated copper line on the bottom of the compressor that runs to the condenser is really hot near the compressor. When the copper line reaches the condenser it is not cold but not hot as near the compressor. Hope this helps Thanks!

     

     

  • fixbear

    Member
    July 25, 2019 at 7:32 am

    Let’s start from the beginning here. 

     

    Machine history’  Was it running before the cap was replaced?

    Room temp,  Air borne grease?

    Water temp incoming?

    Serial number?  They used 3 different 115 volt compressors and the motor start components are not interchangeable.

     

    Now we need to know what conditions the machine displays.

       Motor run amps.

       operating voltage.

       Any water going down drain when running?

       

    refigeration conditions;

       compressor discharge should be very hot. To hot to hold on to.

       top line to evaporator should be hot

       fan should be moving a large amount of air tat feels warm.

       bottom line of condenser should be just above room temp.   

       TXV outlet (larger line) should be very cold.

       evaporator feed line at tne hot gas tee should be cold

       Evaporator inlet should be very cold.

  • fixbear

    Member
    July 25, 2019 at 7:53 am

    olivero wrote:

     

    Now, there’s normally a switch which monitors head pressure and turns the fan on and off as it goes along it’s a common tool across the boards. SO If it’s bypassed and the fan stays on that might just mean that you have a leak, honestly it sounds like there’s not enough refrigerant to go around.

    Low gas will not cause the compressor to overload.  That requires a high head or compressor internal problem or start / run componet problem.  High head can also be a overcharge as well as airflow.

     

    olivero wrote:

     

    D, if the TXV wasn’t working and was starving the evap, your head would run high IF there was a sufficient charge as all that refrigerant would be pumped against a wall but not going anywhere. If that was the case, the fan would remain on as your switch would detect the high head and cycle it on. 

     

     

    A starving metering system  (TXV)  will cause a low load condition. That’s why we need the amps of the compressor. Overload is usually a full open valve.  Whether the TXV or the hot gas leaking and raising the low side pressure.  The hot gas will also cause the fan to cycle as well as not cool but heat the evaporator.

  • olivero

    Member
    July 25, 2019 at 8:48 am

    Okay, sounds like it’s a refrigerant issue.

     

    You’ll need a service tech for it. 

     

    If the compressor is running, the condenser fan is running, then that larger insulated line should be cold coming back. It sounds like it’s low to me.

  • olivero

    Member
    July 25, 2019 at 8:51 am

    Fixbear, If the unit is low on gas and it’s not being cooled by the suction gas, it will overheat. Head won’t be high but it’ll overheat all the same.

     

    Right but his fan is not being triggered on which indicates a low head condition, with no cooling and supposedly low head, it sounds like low head and low suction, which to me, sounds like a low charge issue.

  • fixbear

    Member
    July 25, 2019 at 11:42 am

    With a low charge,It  will get hot, but not usually enough to trip the motor overload.  And the condenser inlet will not be hot, just warm.  The timing of how long it trips is the clue here.  If it is a short trip and comes back on after about 30 to 60 seconds, it will be a starting/winding problem.  If the recovery time is longer, it’s ussually load.  This is providing your starting from  a cold state without the compressor heat saturated.

  • olivero

    Member
    July 25, 2019 at 12:01 pm

    I’ve seen them trip on low charge from a lack of cooling. Depends on how low it is though.

     

    Very true, considering it’s 8 minutes in. I think it’s low.

  • chefhenryclay

    Member
    July 25, 2019 at 7:46 pm

    I have to thank all for helping get this old ice machine back up and possibly running. Fixbear helped me get it back on line and running almost a year ago.with

    Let`s face it, It is an old machine, where we live has an antiquated water system diluted heavily with calcium deposits. That wreaks havoc on ice consistency and overall machine performance (needs cleaning every 2 or 3 weeks). The choice between the cost of fixing an old ice machine without any clear path to a certain soltion vs. a new machine is an easy one.

    I plan on donating the broken ice machine to a school that teaches kids all about hvac and ice machines.

    Thanks again all.

  • fixbear

    Member
    July 26, 2019 at 8:34 am

    Smart decision for sure.  I suspect the the bottom frame is rusted and the ice plate has surface problems making  harvest a bit erratic. But the big unknown is the compressor condition.  I’ve had several of the SC 18’s that have broken a valve spring or had a bearing failure.  I’m not sure what area of Louisiana your in, but if the norther area it might be a bit difficult finding a good tech. 

     

    You would be farther ahead it you address the water quality at the same time.

     

    Thanks for letting us know

  • olivero

    Member
    July 26, 2019 at 8:40 am

    So did it work? what was the problem?

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