1. Basic Electricity

2. Wire Wire consists of: A conductor Insulation Copper (CU)
Copper-clad aluminum
Insulation
Materials are based on the specific application
Designed to be non-conductive

3. Wire and Fuse Sizing Max fuse size Minimum Circuit Ampacity (MCA)
Ground
Voltage drop
National Electric Code (NEC)

4. Wire and Fuse Sizing
High and low voltage wire not allowed in same conduit
Conductor or wire sizing is necessary to allow enough current to flow
Sized by:
American Wire Gauge (AWG)
Amount of amperage permitted to carry
Types most commonly used:
THHN TW

5. Fuses and Circuit Breakers
• A fuse is the simplest form of circuit protection. The word fuse derives from the Latin word meaning “to melt”
• Fuses have been used almost since electricity’s beginning. The earliest type of fuse that was used was a simple bare wire that was smaller than the conductor it was protecting, and therefore would melt before the conductor was harmed
Fuse Symbols
Screw-in style fuse
Cartridge Fuse

6. Circuit Protection
Purpose of circuit protection: 1. To protect the circuit wiring 2. To protect the loads within the circuit Protection from what: 1. Direct shorts 2. Excessive heat 3. Excessive current If these concerns are not protected, the possibilities are endless: fires, deaths, etc., which makes this issue a priority

7. Ratings Fuse Ratings Current Rating Voltage Ratings Time Delay Rating
Standard

8. Circuit Breakers
It is called a circuit breaker because it breaks (opens) the circuit.
The first compact, workable circuit breaker was developed in 1923.
In 1928 the first circuit breaker was placed on the market.

9. Typical Residential Receptacles

10. Typical Romex Nomenclature
When wiring goes through a metal opening, it should be protected from wear by the use of plastic grommets, Romex connectors, or conduit connectors.
Number of insulated wires
Cable type
Max. Voltage Rating
Paper
Wire Gauge

11. Typical Romex Nomenclature
Electrical boxes, furnaces, condensers, and disconnects all need connectors on high and low voltage wire to protect and to secure it
Locknut
Cable Clamp
Cable Sheathing

12. Wiring 120 Volt Wiring (1) Black wire (Hot) potential
(1) White wire (Neutral) potential
(1) Bare or Green wire (Ground) safety!
240 Volt Wiring
(2) Black wires (Hot)
(1) Black (1) Red wire (Hot)
(1) Bare or Green wire (Ground) safety
240 VOLT
If using Romex with a Black and White wire, tape the white insulation with black electrical tape to mark it as a hot wire.

13. When installing wires to switches, receptacles, thermostats, etc
When installing wires to switches, receptacles, thermostats, etc., loop the wire slightly and install the loop in the direction you will tighten screw. Only strip back wire enough to make a good connection. Leaving extra bare wire is dangerous!

14. Duplex Receptacle Switch turns receptacle on and off
Receptacle stays hot. Switch turns appliance on and off

15. Split bolts can be used to join multiple high voltage wires.
Wire Nut and Split Bolt
High voltage wiring can be spliced together with split bolts or wire nuts.
Split bolts can be used to join multiple high voltage wires.

16. Typical Pictorial Diagram of a Condenser
Wires must be in conduit
Conduit must have connectors on both ends
Conduit must be strapped or supported
Try to run conduit straight and at 90 degree angles

17. Low Voltage Components
The air conditioning system is comprised of high voltage and low voltage circuits
What is a transformer?

18. Thermostats Air Conditioner Heat Pump Thermostat Heater Condenser
Thermostat Indoor Unit Outdoor unit

19. Color Code For Low Voltage Thermostat Wiring

20. Color Code For Low Voltage Thermostat Wiring

21. Relays
A relay is a device where current going into a coil creates a magnetic effect, which switches one or more sets of contacts
Different types of relays:
Control duty relays
Fan duty relays
Contactor relays
There are 4 items you need to know about a relay or contactor:
Coil voltage
Contact voltage (maximum)
Contact amperage (maximum)
Contact type (S.P.S.T.; S.P.D.T.)

22. Fan Center
Fan Center is a fancy name for a transformer and fan relay mounted on a 4 x 4 cover plate that can be easily attached to a 4 x 4 gang box
They are primarily used with furnaces that were designed as heating-only systems (both gas and oil) that are being converted for use with air-conditioning
There is typically a wiring diagram available on the fan center