1) I feel ______ that we will finish electrical design today.

A. Happy

B. Sad

C. Indifferent

D. I didn’t know we were studying electrical design

Branch Circuit Design

• Handout for Panel B (~Panel D in other example)

• How to determine size of breaker?• 125% increase in ampacity (safety)

• Allows for longer conductor length

• Some breakers have are for more than one leg (i.e. higher voltage equipment)

• How to determine size of conductor?• Same as earlier work – use breaker amperage

2)What does MLO imply?

A. The panel is a main panel that feeds other panels.

B. The panel requires a main circuit breaker.

C. The panel is probably in a residential building.

D. The panel is probably in a commercial building.

E. The panel is used for higher voltage loads.

3) If the panel has aluminum feeders?

A. It won’t meet the NEC.

B. The feeders will be smaller than if it had copper feeders.

C. The feeders will be larger than if it had copper feeders.

D. The panel is probably in a commercial building.

4) Why are neutral totals not the sum of the power on each leg?

A. You don’t need to include the 125% sizing factor when sizing the neutral

B. Not all of the current goes through the neutral

C. Not all duplex outlets/lighting will be used at the same time

Other Panels

• Examples in text for other panels

• Review guidelines for branch circuits• (I won’t ask memory questions?)

Conduits for Branch Circuits

• Types• AC or MC flexible armored conduit• EMT rigid (thin wall) ½ to 4 inches• IMC/Rigid (thick wall)

• Unless otherwise indicated can use conduit for grounding

• Install conductors for all phases and neutral in same conduit

• Can’t mix wiring (communications, etc.) in conduits• Can’t use conduits smaller than 1 inch and no more

than 9 conductors in a conduit

Procedure

1. Analyze building needs

2. Determine electrical loads

3. Select electrical systems

4. Coordinate with other design decisions

5. Prepare plans and specifications

Lighting in Text

• Chapter 1 – Introduction / lighting design terms

• Chapter 2 – Photometrics• Chapter 3 – Lighting technology• Chapter 4 – Lighting design issues• Chapter 5 – Daylighting• Chapter 6 – Design examples (non-numeric)• Chapter 7 – Design examples (numeric)

Lighting

• Describe why lighting is important

• Describe motivations for lighting

• Calculate basic lighting terms• Photometrics

• List differences between fluorescent and incandescent lamps

• IES Handbook

Source: DOE

Motivation

• Lighting represents a third of commercial building energy use

• Lighting has been measured to influence:• Worker productivity• Retail sales• Mood/emotion/comfort• Accident avoidance/safety

5) Which lamp will give off more light?

A. 100 W incandescent > 85 W halogen > 14 W CFL

B. 14 W CFL > 85 W halogen > 100 W incandescent

C. 85 W halogen > 100 W incandescent > 14 W CFL

D. 100 W incandescent > 14 W CFL > 85 W halogen

6) Which lamp will draw the most power

A. 100 W incandescent > 85 W halogen > 14 W CFL

B. 14 W CFL > 85 W halogen > 100 W incandescent

C. 85 W halogen > 100 W incandescent > 14 W CFL

D. 100 W incandescent > 14 W CFL > 85 W halogen

7) Which lamp will be the hottest?

A. 100 W incandescent > 85 W halogen > 14 W CFL

B. 14 W CFL > 85 W halogen > 100 W incandescent

C. 85 W halogen > 100 W incandescent > 14 W CFL

D. 100 W incandescent > 14 W CFL > 85 W halogen

8) Which lamp will be the most efficient?

A. 100 W incandescent > 85 W halogen > 14 W CFL

B. 14 W CFL > 85 W halogen > 100 W incandescent

C. 85 W halogen > 100 W incandescent > 14 W CFL

D. 100 W incandescent > 14 W CFL > 85 W halogen

Other questions

• Will the 14 W compact fluorescent draw more than 14 W because of the ballast?

• What is the power factor of each lamp?

Homework 2

• By completing this assignment, you should be able to:• 1)Design residential electrical systems

• Locate input data on appliances/devices

• 2)Size commercial electrical panels and electrical systems

• 3)Differentiate lighting efficiency and efficacy