Unit Objectives 205
Branch Circuits
Safety Switches
Distribution Panelboards
Low-Voltage Switchgear
Service Entrance- Explain the operation of single-phase/two-wire and single-
phase/three-wire power distribution systems. - Explain the operation of three-phase/three-wire, three-phase/
four-wire, and three-phase/three-wire with neutral power
distribution systems. - Describe and sketch diagrams of delta-delta, delta-wye, wye-wye,
wye-delta, and open delta three-phase transformer connection
methods. - Describe the following in relation to grounding of electrical power
systems:
System Ground
Equipment Ground
Ground Fault Circuit Interrupters - Explain the use of the National Electric Code (NEC) as a standard
for electrical power distribution design in the United States. - Calculate voltage drop in an electrical circuit using a conductor
table or circular mil formula. - Calculate voltage drop in a branch circuit or feeder circuit for a
single-phase or three-phase distribution system. - Determine grounding conductor size by using the proper tables.
- Describe the following in relation to electrical power systems:
Nonmetallic Sheathed Cable
“Hot” Conductor
Neutral Conductor
Safety Ground
AWG and MCM Conductor Sizing
Metal-Clad Cable
Rigid Conduit
Electrical Metallic Tubing (EMT)
Uninterruptible Power Supply (UPS)
Power Line Filter
Power Conditioner
Floor-Mounted Raceway
Conduit Connectors