HVAC WiringUnderstanding
Wiring
HVAC Wiring
• Wiring diagrams are road maps for electron flow
HVAC Wiring
HVAC Technicians must know:
• How to draw them
• How to read them
HVAC WiringDrawing diagrams• Begin with a
description of how the circuit is too work
Draw a diagram a main single pole/single throw switch that controls all loads. A single pole/single throw switch controlling a 60w bulb. A single pole/single throw switch controlling two 40w bulbs connected in parallel. A single pole/double throw switch controlling a 40w bulb in one position and two 60w bulbs wired in series controlled when the single pole/double throw switch is in the other position.
HVAC Wiring
Drawing diagrams
• Next Create a Written flow chart
HVAC Wiring
Drawing diagrams• Use the flow chart
to complete a Ladder Diagram
• Place the switch that controls everything of L1
HVAC Wiring
Drawing diagrams
• Using the flow chart add a circuit that add a branch circuit
• Place a spst switch in series with a 60w bulb
HVAC Wiring
Drawing diagrams• Use the flow chart
to complete a Ladder Diagram
• Now place the next switch in the circuit
HVAC Wiring
Drawing diagrams• Use the flow chart
to complete a Ladder Diagram
• Place the bulbs controlled by the switch in the circuit
HVAC Wiring
Drawing diagrams• Use the flow chart
to complete a Ladder Diagram
• Complete the ladder with the last circuit
HVAC Wiring
Drawing diagrams• Use the Ladder
Diagram to wire the project board
• Wire one branch at a time
HVAC Wiring
Drawing diagrams• Note how since L1
power has been brought to SW1 that is where we can pick up power for the next switch
HVAC Wiring
Drawing diagrams• Note how since N
or L2 has been brought to Bulb 1 we use any terminal that has a direct line back to N/L2 as a connection to N/L2
HVAC Wiring
Drawing diagrams• Complete project
HVAC Wiring
Drawing diagrams• Note alternate L1
connections