02 - Grounding and Bonding: Grounding Systems, Bonding Requirements

Send us Fan MailUnderstand the critical difference between grounding and bonding. Learn how grounding protects equipment from voltage surges while bonding protects people by clearing ground faults through low-resistance return paths.Show Notes (Full):Episode OverviewGrounding and bonding are often confused but serve distinct safety functions. This episode clarifies these critical concepts and explains why proper installation is essential for electrical safety in every home.What You'll LearnUnderstanding the Difference:Grounding protects electrical equipment (acts like surge suppressor)Bonding protects people (clears ground faults safely)Why both systems are essential but serve different purposesHow voltage surges find safe paths to groundWhy bonding provides low-resistance return paths for fault currentHow Bonding Clears Ground Faults:What happens when a hot wire contacts metal (the "rat example")Why low resistance is critical (high resistance = circuit breaker won't trip)How Ohm's Law determines current flow in bonded circuitsWhy loose bonding clamps create deadly hazardsThe myth: electricity doesn't "want" to go to ground—it returns to its sourceGrounding Electrode System Components:Grounding electrodes: rebar, rods, pipes, metal water serviceGrounding electrode conductor (GEC) sizing and installationWhere the GEC connects (between service drop and service equipment)Why multiple grounding connections downstream are prohibitedUfer grounds and concrete-encased electrodesBonding Requirements:Metal water and gas distribution pipesElectrical conduit, equipment cabinets, and casesHVAC ducts and metal framingCSST gas tubing (special bonding requirements)Satellite and cable TV coaxBonding jumpers around interruptions (water meters, plastic components)Equipment Grounding Conductors (EGCs):EGCs are really bonding wires, not part of grounding systemProvide low-resistance return path for equipment that may become energizedFound in modern electrical cable since approximately 1960Typical Defects to ReportDamaged, loose, or undersized GEC (#8 min for <150A, #6 min for ≥150A)Absent or loose grounding/bonding clampsClamps on corroded, painted, or contaminated surfacesImproperly spliced GEC (must use listed compression connector or welding)Metallic conduit with plastic fittings (bonding path interrupted)Underground water pipe GEC connection >5 feet from entry pointMissing bonding jumpers around water meters and removable componentsCSST gas tubing not bonded properlyKey TakeawaysGrounding limits voltage surges; bonding clears ground faultsLow resistance bonding paths are essential for safetyAll accessible grounding electrodes must be bonded togetherMetal that could carry electricity must be intentionally connectedGEC connection occurs only once—at or before service equipmentCritical Safety Principle"If it is metal and it is or could be near electrical wires, then it probably needs to be bonded to the grounded wire of the utility."IRC Code ReferencesIRC 2018: E3607, E3608, E3609, E3610, E3611, G2411Study TipsFocus on understanding WHY bonding matters, not just memorizing requirementsPractice identifying bonding defects in photos and during field trainingRemember: loose connections = high resistance = safety hazardLearn proper GEC sizing for different service ampacitiesIntro This episode is brought to you by GetSync.pro This episode is hosted by Charlie Bellefontaine of Chicagoland Home InspectorsFor complete training with visual materials, practice exams, and certification support, visit nhiexamprep.com© 2025 National Home Inspector Exam Prep Podcast. All rights reserved.