This document provides an overview of residential wiring, including: - Residential circuits are connected in parallel to distribute voltage evenly and prevent failures from affecting other circuits. Resistive and motor loads affect power consumption differently. - Improving power consumption can involve adding capacitors in parallel to certain loads. - Electrical components like sockets, switches, cables, and protection devices are described along with their purposes in the residential wiring system. Service panels and distribution panels are also summarized.

1. Residential Wiring
By: Ing. Hector M Lugo-Cordero, MS
03/25/2009

2. Agenda
• Residential circuits
• Improving power consumption
• Sockets
• Switches
• Cables
• Protection devices
• Service panel
• Distribution panels
• Electrical symbols

3. Residential Circuits
• Residential loads are connected in parallel,
since the voltage remains the same through the
loads and if a circuit fails it does not affect the
others
• Purelly resistor load (e.g. lights, toaster)
– Demand P = VIcos(av – ai)
– cos(av – ai) is the power factor
• If a motor is added (e.g. celing fan, refrigerator)
– Demand Q = VIsin(av – ai), as well as P
– sin(av – ai) is the reactive factor

4. Improving Power Consumption
• Add a capacitor/capacitor block in parallel
to the load
• Make sure is the right one
• Don’t add it to purely resistor circuits

5. Sockets
• A power socket is used for connecting
appliances.
• Big hole specifies the neutral end (to source)
• Small specifies the hot end (from source)
• Examples
– 125V @ 15A
– 125V @ 20A
– 230V @ 30A
– Ground Fault
– Arc Fault

6. Switches
• Switches allow the user to control a load
(on/off)
• Examples
– Single
– Double
– 3 way
– 4 way
– Combined
– Pilot light

7. Cables
• Black – hot, connection from the AC
source to switch typically
• Red – return, connection from switch to
load
• White – neutral, connection from load
back to the AC source, it closes the circuit
• Green – ground, protects people from
electrically charged metal parts

8. Size of Cables
• 14: minimum approved width in United
States for residential wiring. In PR we can
use it for lamps wiring
• 12: minimum approved width in Puerto
Rico for residential wiring
• 2: cable used from service panel to
distribution panel, passes up to 100A of
current

9. Size of Cables (cont.)

10. Protection Devices
• Breakers: work like a fuse, opens
current path when threshold is
exceeded. This protects the
circuits from high currents, no
protection to people
• Ground connection: connection to
ground so that users are
protected from alternate current
paths, like breakers they open the
current path but when a current
change is found

11. Service Panel
• Nude cable comes
from transformer
• It then changes to a
white cable and
connects to the box
• From here a
connection to
breaker and ground
is done

12. Distribution Panels
• Load balancing: the act of distributing
equally all 120V loads

13. Electrical Symbols