Timer Charts, Start Winding Polarization, and more Live Dojo Tech Talk

Every other week, all the finest techs of Appliantology gather in cyberspace for a Live Dojo workshop, where we discuss hard-hitting technical topics, industry secrets, and all else appliantological.

You may have missed the live workshop on December 23rd, but never fear! We’ve documented the discussion for posterity here. Topics covered include:

  • Deciphering a washer’s timer chart and schematic and using them for troubleshooting
  • Analyzing the operation of a pump motor using the timer chart and schematic
  • How the polarization of the start winding affects the rotational direction of a split-phase motor
  • Fluke meter questions and concerns
  • Bosch dishwasher “run forever” problem and potential soldering repair
  • The potential benefits of warranty work for appliance manufacturers

Keep scrolling for a summary of the conversations. Also, here’s a recording of Team Samurai’s troubleshooting using timer charts presentation – viewable only by premium members of Appliantology.

Not a premium member? You can become one today for free by enrolling in any technical course right here at Master Samurai Tech.

Live Dojo Workshop Summary

Sam kicked things off by discussing a washer’s timer chart and schematic in relation to each other. He explained how different numbers in the chart correspond to the switches in the timer part of the schematic. The different numbers in the left column of the timer chart refer to the mechanical cams in the motor and the different switches in the timer, and Sam emphasized the importance of correctly interpreting the numbers for testing purposes. He further explained the process of analyzing a load using the timer chart and schematic, highlighting the need to think in terms of how a circuit needs to function to ensure its proper operation. He demonstrated this by walking through the operation of a pump circuit.

Drive Motor Operation Discussion

The operation of the main drive motor in agitate mode was also discussed, with Sam highlighting the role of the start winding in initiating motor rotation. Scott emphasized the start winding’s role in split-phase motors, explaining that it creates a temporary second phase to start the motor spinning. He further explained that the direction of motor rotation can be controlled by the polarization of the start winding in relation to the run winding.

Sam and Scott had a detailed discussion about the operation of a circuit, specifically focusing on the timer chart for contacts 6 and 8. Sam clarified that different contacts would be closed depending on the agitate direction and confirmed that timer contact 12 was a typo and should be 15. Scott stressed the importance of understanding the physical workings of the circuit to avoid errors.

Later, we discussed the electrical representation of a motor, emphasizing the reversal of the start winding’s polarization relative to the run winding, which controls the direction of motor rotation. The motor turned in one direction for agitation, and the other direction for spin, and this direction of rotation was controlled by the polarization of the start winding relative to the main winding.

Fluke Meter Concerns

Afterward, one of the techs raised a concern about their fluke meter and its resistance readings, which was addressed by Scott. Scott suggested that oxidation on the leads could cause inaccurate readings, and recommended using gold-plated leads, available on Amazon. He also advised against relying heavily on ohms measurements due to their inaccuracies. A tech also asked about amperage readings and the sensitivity of the meter, to which Scott clarified that modern meters auto-range and can handle different currents without adjustments.

Bosch Dishwasher Runs Forever and Potential Soldering Repair

We discussed a customer’s issue with a Bosch dishwasher that continues to run even without terminating the cycle. Scott advised Brian to check for potential flood conditions and a burn spot on the board in the heating circuit. In some cases, the issue could be corrected by a simple soldering job. The techs further discussed the reliability of solder joints and the failures they could suffer due to the cost-saving measures taken by manufacturers, such as using less solder or lighter joints, leading to those solder joints failing later on.

Manufacturing Training and Warranty Benefits Discussed

A tech expressed interest in obtaining manufacturing training, to which Scott advised them about the benefits of doing warranty work for higher-end brands such as Miele, Sub-Zero and Bosch. Another tech suggested using Appliantology, a platform for professionals to share resources and information, and Scott emphasized its value as a searchable database for repairs.

Want to watch the timer-chart troubleshooting discussion with all the juicy, technical details? Click below to view the full video – viewable only by premium members of Appliantology.

Not a premium member? You can become one today for free by enrolling in any technical course right here at Master Samurai Tech.