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Symbio 700 Board Failures (No Fault Found) - Troubleshoot before considering return

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Summary:

Trane has seen a high percentage of S700 UC boards returned with no fault found. There is a need to investigate board failures in the field before replacing the board. Properly troubleshooting the board can prevent unwarranted labor/parts costs, extra site visits, and a misdiagnosis of the true problem/issue,

Link to contact Tech Support for help        

What are known Diagnostics or Symptoms:

Compressor Proving Faults.

 

Product Family: NextGen Voyager 3, Large and Small Precedent, Odyssey                            

Model Prefix(s) & Configuration details: YSJ, YHJ,YSK,YHK, YZJ, YZK, TSJ, THJ, TSK, THK, TZJ, TZK, WSJ, WHJ, WSK, WHK, DSJ, DHJ, DSK, DHJ, TTA, TWA, TCD, TCH, TCF, TCR, TED, TEH, TEF, TER, YCD, YCH, YCF, YCR

Ship Date range: <enter specific date range, if unknown-remove this line>

Serial range: 2020**** to Present for Odyssey Condensing Units

Serial range: 2250**** to Present for Large and Small Precedent Units

Serial range: C23A**** to Present for Voyager 3 Units

 

What actions can I take now: 

 

First, Check for latest firmware revision. Make sure it is up to date. 

Click here on how to update firmware.

 

Second, Verify your unit configuration. Make sure it is correct.

Click here on how to check configuration with the mobile app. 

Click here on how to check configuration without the mobile app. 

 

Finally, Contact Technical Support

Link to contact Tech Support for help   

When submitting ticket request, please put in unit diagnostic in the subject line. 
 

PLEASE FOLLOW TROUBLESHOOTING STEPS OUTLINED BELOW BEFORE CONTACTING TECHNICAL SUPPORT.

  • FOR VOYAGER 3 FOLLOW THESE STEPS:
  • This diagnostic is created when the unit calls for a compressor contractor to energize, and the contactor does not pull in or drops out during operation.  This would normally indicate that a safety (HPC or DTL) has opened, but anything that causes the aux contacts on the contactor to show as open when they should be closed will generate this diagnostic.
  • If the contactor does not pull in when requested, check wire connections.  Poor wire connections in the wire harness seem to be the biggest issue we are seeing, primarily the two pin harness connectors for the HPC's, DTL's, and the compressor contactor coils.  (See attached schematic).  These connectors are only there for ease of assembly purposes.  We have suggested removing them and using wire nuts or splices to correct the issue as a field fix.  In many cases, this solves the problem.
  • Other, less obvious, causes can be a tripped transformer or poor harness connection on the Adapter Board.  Compressor Contactors 1 and 2 get their 24 VAC power from the transformer connected to J25 on the Adapter Board.  Compressor Contactor 3 gets its 24 VAC power from the transformer connected to J8 on the Adapter Board.  Verify that these two connectors on the Adapter Board are receiving 24 VAC.  If either of these transformers have tripped, failed, or have a poor harness connection the unit will generate this diagnostic when it calls for the compressor to start.
  • It is also possible to have a bad aux switch on the compressor contact.  If the contactor pulls in, but drops out a few seconds later, check the proving switch and wiring.
  • A test that can be performed is:
  • 1.) Power down the unit/verify that there is no voltage present on the compressor contactors
  • 2.) Remove the fuses for the compressor or Load wiring to the contactor of the compressor you're troubleshooting (in this example we'll cover CC1/Compressor 1 proving).
  • 3.) Insert a jumper into the P8 plug between pins 4 & 5 (Orange and Yellow wires...see snip below from the schematic).

  • 4.) Power on the unit and verify that the CC1 contactor pulls in and you have 24Vac present on P8 pin 3  (blue wire) for the proving input...if the CC1 does not pull in then there could be a lack of 24Vac, loose connection, or an open safety as mentioned above. If the CC1 does pull in and you do have 24Vac on pin 3 of P8 and you continue to get Compressor 1 Proving diagnostics then there could be an issue with the Symbio 700. You can repeat/copy these steps for CC2 and CC3 (Compressor 2 is the P9 and Compressor 3 is the P10).

    Adaptor Board.png

  • FOR LARGE AND SMALL PRECEDENT FOLLOW THESE STEPS:

  • Precedent:

  • Circuit 1 Run Command Path
  • Compressor 1 run command from UC P8-5 to Adapter Board J20-5.
  • Then, to Adapter Board J13-1 by board trace.
  • Out to the HPC1 and back to Adapter Board J13-2.
  • Then, to Adapter Board J13-3 by board trace.
  • Out to DTL1 and back to the Adapter Board J13-4.
  • Then, to Adapter Board J5-9 by board trace, then out to CC1 coil.
  • Continuity Test:
  • When the unit is powered off, disconnect the J8 plug from the Unit Controller. Leave all the other plugs plugged in. Place one of the leads on J8-5 (yellow wire) and the other on the Adapter Board J5-10 (yellow/brown wire).
  • If the meter reads OL, work yourself back, verifying where it's open, and look at the drawing below and the unit drawings.
  • Between the adapter board and the CC1 coil, there are two plugs: PPF81/PPM81 and PPF/PPM23
  • Between the adapter board and the CC1(AUX1) there is one plug: PPF81/PPM81 

  •  

  • Circuit 1 Proving Circuit Path
  • The Proving Circuit is UC P8-2 to J20-2.
  • To Adapter Board J5-5 by board trace.
  • Through the Aux switch to J5-6.
  • To Adapter Board J20-3 by board trace.
  • Then to UC P8-3
  • Continuity Test:
  • When the unit is powered off, disconnect the J8 plug from the Unit Controller. Leave all the other plugs plugged in. Place the lead on J8-2 (red wire) and the other on J8-3 (blue wire).
  • Your meter will read OL until the contactor is pressed in. 

  • If you still read OL, move the lead from J8-3 to the Adapter Board J20-3 (blue wire) and work yourself back to verify where it's open; look at the wiring below and the unit drawings.

  • Circuit 2 Run Command Path
  • Compressor 2 run command from UC P9-5 to Adapter Board J20-11.
  • Then, to Adapter Board J11-1 by board trace.
  • Out to the HPC2 and back to Adapter Board J11-2.
  • Then, to Adapter Board J11-3 by board trace.
  • Out to DTL2 and back to the Adapter Board J11-4.
  • Then, to Adapter Board J5-11 by board trace, then out to CC2 coil.
  • Continuity Test:
  • When the unit is powered off, disconnect the J9 plug from the Unit Controller. Leave all the other plugs plugged in. Place one of the leads on J9-5 (brown/black wire) and the other on the Adapter Board J5-12 (black/red wire).
  • If the meter reads OL, work yourself back, verifying where it's open, and look at the drawing below and the unit drawings.
  • Between the adapter board and the CC2 coil, there are two plugs: PPF81/PPM81 and PPF/PPM24

  • Between the adapter board and the CC2(AUX1) there is one plug: PPF81/PPM81 

  • Circuit 2 Proving Circuit Path
  • The Proving Circuit is UC P9-2 to J20-8.
  • To Adapter Board J5-7 by board trace.
  • Through the Aux switch to J5-8.
  • To Adapter Board J20-9 by board trace.
  • Then, to UC P9-3
  • Continuity Test:
  • When the unit is powered off, disconnect the J8 plug from the Unit Controller. Leave all the other plugs plugged in. Place the lead on J9-2 (blue/black wire) and the other on J9-3 (orange/black wire).
  • Your meter will read OL until the contactor is pressed in. 

  • If you still read OL, move the lead from J9-3 to the Adapter Board J20-9 (orange/black wire) and work yourself back to verify where it's open; look at the wiring below and the unit drawings.

  • FOR ODYSSEY FOLLOW THESE STEPS:

    Odyssey:

    Circuit 1

    • Compressor 1 run command from UC P8-5 to Adapter Board J20-5.
    • Then, to Adapter Board J13-1 by board trace.
    • Out to the HPC and back to Adapter Board J13-2.
    • Then, to Adapter Board J13-3 by board trace.
    • Out to DTL and back to the Adapter Board J13-4.
    • Then, to Adapter Board J7-1 by board trace, then out to CC1 coil.
    • The Proving Circuit is J5-1 to J22-1 through the Aux switch, to J22-2 to J20-3, then to UC P8-3.

     

    mceclip0.png

     

    Circuit 2

    • Compressor 2 run command from UC P9-5 to Adapter Board J20-11.
    • Then, to Adapter Board J11-1 by board trace.
    • Out to the HPC and back to Adapter Board J11-2.
    • Then, to Adapter Board J11-3 by board trace.
    • Out to DTL and back to the Adapter Board J14-4.
    • Then, to Adapter Board J7-3 by board trace, then out to CC2 coil.
    • The Proving Circuit is J5-1 to J22-3 through the Aux switch, to J22 -4, to J20-9, then to UC P9-3.

     

    mceclip1.png

     

     

    Relay Contact Resistance Test

    Symbio 700 UC P8 CC1 Relay contact resistance check steps

    1. Unplug the J8 harness from the Red P8 connection on the board. Pay attention to which connector pins the Orange and Yellow wires are connected too.
    2. Connect to the Symbio 700 UC board with the cell phone app and go to the Tools > Service Test Mode page.
    3. Click on Cool 2 to energize the compressor relay output on the Symbio 700 UC. LED 5 on the Symbio 700 UC board should be ON.
    4. Check the relay contact resistance across the connector pins where the Orange and Yellow wires were connected. You will only have about 5 seconds to check this before getting a proving fault.
      The resistance should be less than 10 ohms.
    5. Repeat this process a few times to see if the relay contact ohm reading changes. If the ohm reading goes above 10 ohms, the Symbio 700 UC board will need to be changed.

     

     

     

     

    Symbio 700 UC P9 CC2 Relay contact resistance check steps

    1. Unplug the J9 harness from the White P9 connection on the board. Pay attention to which connector pins the Y/BK and BR/BK wires are connected too.
    2. Connect to the Symbio 700 UC board with the cell phone app and go to the Tools > Service Test Mode page.
    3. Click on Cool 1 to energize the compressor relay output on the Symbio 700 UC. LED 15 on the Symbio 700 UC board should be ON when compressor 2 is energized.
    4. Check the relay contact resistance across the connector pins where the Y/BK and BR/BK wires were connected. You will only have about 5 seconds to check this before getting a proving fault.
      The resistance should be less than 10 ohms.
    5. Repeat this process a few times to see if the relay contact ohm reading changes. If the ohm reading goes above 10 ohms, the Symbio 700 UC board will need to be changed.

     

     

     

    Compressor Proving Alarms

     

    Possible Alarms:

    Alarm - Compressor Proving Trip Diagnostic – 15-minute lockout

    • The HPC or DTL opens while the compressor is running, (after the circuit has proved) and the Compressor Contactor loses its 24 VAC, causing the Aux Switch to open

     

    Alarm - Compressor Proving Lockout Diagnostic – INSTANT UNIT LOCKOUT!

    • The Symbio Board calls for the Compressor Contactor, and the Contactor doesn’t pull in within 7 seconds.

    Possible causes:

    The HPC and or the DTL are open.

    Contactor Coil open.

    Wiring error.

     

    Alarm - Compressor Proving Lockout Diagnostic – INSTANT UNIT LOCKOUT!

    • The Symbio Board calls for the Compressor Contactor, it pulls in and drops back out after 7 seconds.

    Possible causes:

    No 24 VAC at black wire on the Aux Switch

    Bad Aux Switch.

    Aux Switch is not on the contactor correctly.

     

    Alarm - Compressor Contactor Fail Diagnostic – INSTANT UNIT LOCKOUT!

    • The Compressor Contactor Aux Switch closes before it is supposed to

    Possible causes:

    The technician pushes in the contactor manually.

    The contactor welded shut.

     

    💡 Note:

    • A good way to determine whether the pressure switches or the board/wiring are the issue is to unwire the line voltage from the compressor in question and isolate it. Have the Symbio 700 Board turn on the circuit. If the circuit operates normally with the compressor line voltage unwired, you may have a refrigeration issue. If you still get a proving diagnostic, you may have a board/wiring issue.

     

    CONTACT TECHNICAL SUPPORT FOR ASSISTANCE IN DIAGNOSING S700 BOARDS IF NEEDED. IF RMA IS REQUIRED, CONTACT SUPPORT FOR TICKET NUMBER.

  • RECORD ZENDESK TICKET NUMBER IN FQA BEFORE COMPLETING JOB.
  • Enter FQA (Field Quality Alert)
  • Provide specific data or pictures
  • Hold – do not Start/Install
  • Return Defective Part
  • Replace Part

 

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