HVAC Wiring

1
HVAC Wiring

• Understanding Wiring

2
HVAC Wiring

• Wiring diagrams are road maps for electron flow

3
HVAC Wiring

• HVAC Technicians must know
• How to draw them
• How to read them

4
HVAC Wiring

• Drawing 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.
5
HVAC Wiring

• Drawing diagrams
• Next Create a Written flow chart

6
HVAC Wiring

• Drawing diagrams
• Use the flow chart to complete a Ladder Diagram
• Place the switch that controls everything of L1

7
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

8
HVAC Wiring

• Drawing diagrams
• Use the flow chart to complete a Ladder Diagram
• Now place the next switch in the circuit

9
HVAC Wiring

• Drawing diagrams
• Use the flow chart to complete a Ladder Diagram
• Place the bulbs controlled by the switch in the
  circuit

10
HVAC Wiring

• Drawing diagrams
• Use the flow chart to complete a Ladder Diagram
• Complete the ladder with the last circuit

11
HVAC Wiring

• Drawing diagrams
• Use the Ladder Diagram to wire the project board
• Wire one branch at a time

12
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

13
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

14
HVAC Wiring

• Drawing diagrams
• Complete project

15
HVAC Wiring

• Drawing diagrams
• Note alternate L1 connections