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