Thermo Scientific MR05 Series User Manual (English)

Questions and Answers:

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Jonathan WalkerAug 25, 2025
Why does Thermo Scientific MR05 compressor start, but not switch off of start winding?
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  Robyn AveryAug 25, 2025
  If the compressor in your Thermo Scientific Refrigerator starts but doesn't switch off the start winding, it could be due to several reasons. Begin by checking for low voltage to the unit and correct it. Then, inspect the run and start capacitors, replacing them if they have failed or are incorrect. A faulty start relay could also be the cause, so replace it if necessary. Additionally, check the motor for any electrical issues such as open windings, short circuits, or burnouts. In some cases, internal mechanical trouble within the compressor may be the problem, requiring a compressor replacement. Finally, verify that the wiring is correct by checking it against the wiring diagram. Excessively high discharge pressure can also cause this issue.
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Jeffrey SmithAug 26, 2025
Why does Thermo Scientific MR05 compressor run long or continuously?
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  Brian EscobarAug 26, 2025
  If your Thermo Scientific Refrigerator's compressor is running long or continuously, several factors could be responsible. Start by checking for a shortage of refrigerant and look for any leaks. If found, repair them. The control contacts might be stuck or frozen, so try cleaning them or replacing the control. An excessive load in the refrigerated air space could also cause this, so determine the reason and correct it. Additionally, a dirty condenser can lead to continuous running, so clean the condenser. If the evaporator coil is iced, defrost it and check the defrost circuit. A restriction in the refrigeration system may also be the reason, so determine its location and remove it. Finally, ensure the evaporator fan motors are running and check the door switch.
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Sonya BakerAug 28, 2025
What to do if Thermo Scientific Refrigerator compressor hums but trips on thermal overload?
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  edgarriveraAug 28, 2025
  If the compressor in your Thermo Scientific Refrigerator will not start, but hums and trips on thermal overload, several issues may be the cause. First, check for low voltage to the unit and correct it. Then, inspect the start capacitor and run capacitor, replacing them if they have failed or are incorrect. A faulty start relay could also be the cause, so replace it if necessary. Additionally, check the motor for any electrical issues such as open windings, short circuits, or burnouts. In some cases, internal mechanical trouble within the compressor may be the problem, requiring a compressor replacement. Finally, verify that the wiring is correct by checking it against the wiring diagram. Excessively high discharge pressure can also cause this issue.
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Craig IbarraAug 30, 2025
Why is Thermo Scientific Refrigerator compressor noisy or vibrating?
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  whitepamelaAug 30, 2025
  If the compressor in your Thermo Scientific Refrigerator is noisy or vibrating, several factors could be the cause. Start by checking for flooding of refrigerant into the crankcase, and inspect the expansion device and refrigerant charge. Improper piping support can also cause noise, so relocate tubing or add hangers. A worn compressor can also be noisy, so consider replacing it. Look for any loose parts or mounting and tighten them. Lastly, check the condenser fan blade for looseness or obstructions and repair as needed.
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tfergusonAug 31, 2025
Why does Thermo Scientific MR05 compressor short cycle on temperature or pressure controls?
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  Marc WestSep 1, 2025
  If your Thermo Scientific Refrigerator's compressor starts and runs, but short cycles on temperature or pressure controls, consider these possible causes: The differential may be set too close, so try widening it. High discharge pressure, and low discharge pressure can also cause short cycling.
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Samuel DixonSep 2, 2025
Why is ice accumulating on the ceiling of my Thermo Scientific MR05?
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  kthompsonSep 2, 2025
  If you notice ice accumulating on the ceiling around the evaporator and/or on the fan guards or blades in your Thermo Scientific Refrigerator, there are several potential causes. The defrost duration might be too long, so adjust the defrost termination. The fan delay might not be delaying the fans after the defrost period, indicating a defective fan delay thermostat that needs replacement. A defective timer could also be the issue, requiring replacement. Finally, there might be too many defrost cycles per day, so adjust the timer for fewer defrost cycles.
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Raymond DanielsSep 4, 2025
Why is the suction line frosted on my Thermo Scientific MR05 Refrigerator?
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  Kathryn MccartySep 5, 2025
  If the suction line of your Thermo Scientific Refrigerator is frosted or sweating, several issues could be the cause. The expansion valve may be passing excess refrigerant or is oversized, so readjust the valve or replace it with a smaller one. The expansion valve could also be stuck open, in which case you should clean the valve of foreign particles and replace it if necessary. Ensure the evaporator fan motors are running, checking the door switch. Finally, the system may be overcharged with refrigerant, so correct the charge.
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Vanessa SerranoSep 6, 2025
Why is evaporator coil not clearing of frost during defrost cycle in Thermo Scientific Refrigerator?
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  mariadeanSep 6, 2025
  If the evaporator coil in your Thermo Scientific Refrigerator is not clearing of frost during the defrost cycle, several factors could be responsible. The coil temperature may not be getting above the freezing point during defrost, so check the heater operation or hot gas solenoid valve. There might not be enough defrost cycles per day, so adjust the timer for more defrost cycles, or the defrost cycle might be too short, so adjust the timer for a longer defrost cycle. A poor door seal can also contribute to this issue, so adjust the door latch and install a new gasket. Finally, a defective timer or defrost thermostat could be the cause, requiring replacement of the defective component.
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Ryan ScottSep 8, 2025
What causes high suction pressure in Thermo Scientific Refrigerator?
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  Nicholas MartinezSep 8, 2025
  If you are experiencing high suction pressure in your Thermo Scientific Refrigerator, there are two primary causes to consider: The unit may be experiencing an excessive load, in which case you should reduce the load or add additional equipment. Alternatively, the expansion valve may be overfeeding, so check the remote bulb and adjust the superheat.
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Michael AnthonySep 10, 2025
Why is ice accumulating in the drain pan of my Thermo Scientific MR05?
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  Dwayne MillsSep 12, 2025
  If you're seeing ice accumulating in the drain pan of your Thermo Scientific Refrigerator, several issues could be the cause. The heater may be defective, so replace it. The unit may not be pitched properly, so check and adjust if necessary. The drain line could be plugged, so clean it. A defective drain line heater could also be the problem, so replace the heater. Poor contact between the drain pan and heater element can also cause ice accumulation, so repair it. Finally, a defective timer or defrost thermostat could be the cause, so replace the defective component.