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Basic Electricity for the HVAC Contractor

Targeted to field personnel, but it is open to anyone interested in understanding the basics information necessary to properly understand, install and service the electrical circuits commonly associated with HVAC equipment.

What is Covered
Part 1 - Atoms, Current Flow and Circuits (1 hour)

Electricity is defined relative to atomic structure. Current flow through conductors and insulators is explained using a water system analogy. The basic principles of electricity are discussed such as the necessary components for current to flow, short circuits, magnetism and transformers are all discussed. Series and parallel circuits are discussed and how voltage, amperage and resistance react in each.

Part 2 - Relays, Contractors and Motors (1 hour 40 minutes)
Electrical symbols and switches are explained. Relays and contractors are defined. Application and wiring diagrams are offered for a condenser fan circuit, humidifier, furnace, converting a heating only system to heat/cool and converting a powerpile system to 24 VAC. Solenoids and heat anticipation are considered for heating and cooling systems. Electric motor construction including windings and bearings are discussed. Motor types, specifications and how to order a replacement motor are considered. PSC motor facts and the Fan Laws are explained.

Part 3 - Ohm's Law, Series and Parallel Circuits, and Meters (57 minutes)
Ohm’s Law is explained using formula and three phase use and application to an electric HWH is considered, Series and parallel circuits are revisited with respect to voltage, amperage and resistance with application to remote sensors. Wire sizing charts are discussed as well as electrical indicating devices. Open and closed switches are explained and appropriate reading indications are considered.

Part 4 - Schematic Diagrams, Electrical Service Panels and Compressors (1 hour 58 minutes)
Schematic diagram use and application are discussed. Modern furnace and A/C circuits are examined. Testing for polarity, ground and voltage drop are explained. AC electrical panels are considered with reference to line to line voltage and loads. Single phase and three phase compressor internal wiring and diagnostics are discussed. Capacitor construction and application are explained.

Part 5 - Power Distribution and Electrical Safety (50 minutes)

Checking a contractor is explained using a voltmeter and an ohmmeter. Phasing transformers is demonstrated as well as checking fuses with a voltmeter. Power distribution, Delta and Wye transformers and High-Leg voltages are discussed. Electrical safety, dangerous current levels and shock and First Aid are all discussed and explained.