Communication System Refresher Class: From Wire Testing to Buck and Boost Solutions

What You’ll Learn:

• How to identify communication vs. power wiring issues
• Proper wire testing techniques using multimeters on mega-ohm settings
• The most common causes of communication failures
• How to check for subtle wire rub-outs that don’t blow fuses
• ICM voltage calibration and high voltage connection points
• When and how to use Buck-Boost transformers for power quality issues
• Professional tricks for field diagnosis and temporary testing
• Why separate wire runs are critical for Lennox systems
• Proper handling techniques for sensitive modern control boards

Key Topics Covered:

• A/B communication wire basics (green/yellow on Infinity systems)
• Difference between 24V power and DC communication signals
• Step-by-step wire continuity and isolation testing procedures
• Environmental factors affecting communication (water, vibration)
• Resistance testing standards (85-90 ohms maximum)
• AC voltage bleed-over detection on communication lines
• Field testing with temporary wire runs
• When to call technical support effectively

Perfect for both new technicians learning communication systems and experienced techs looking to sharpen their diagnostic skills. Bert’s practical approach combines real-world experience with hands-on demonstrations using actual test equipment.