Building Systems and Performance: an Introduction to Building Operator

Certification –Lesson 1

BOC Introduction and Power Basics

CUNY Institute for Urban Systems Building Performance Lab

Lesson 1:BOC General Introduction

& Power Basics

Section 1 BOC Intro/Overview (15 mins)Section 2 Electricity Fundamentals (45 mins) Section 3 Electrical Circuits (30 mins)Section 4 Electrical Maintenance Issues (45 mins)Section 5 Building Electrical Systems & Safety (45 mins)

2

• BOC – sponsored by CUNY Building Performance Lab (CUNY BPL).

• What is the BOC training designed to do/provide?• Syllabus:

• Schedule• Readings• General info – grading, certification

• Questions:• What do you hope to get out of the training?• Are there specific topics you are especially interested in?• What kinds of issues are most common in your facility?

Section 1: BOC Overview3

Resources: FEMP O&M Manual

CUNY Building Performance Lab

• This is an ONLINE DOCUMENT, can only be accessed via hyperlinks on electronic syllabus!

• Page numbering – look on RIGHT-HAND SIDE of the table of contents for correct PAGE NUMBER – ie. section 9.10 begins on page 9.109

4

Section 2 – Electricity Fundamentals

• Magnetism and Induction

• Motors and Generators

• Electrical Terms and Ohm’s Law

5

- +ELECTRON FLOW

CONCEPTUAL VIEW OF A CONDUCTOR WITH APPLIED VOLTAGE

+

-

PROTON NEUTRON

ELECTRONORBIT

BASIC ATOMIC STRUCTURE

NUCLEUSELECTRON

Electricity Basics6

(Electro-) Magnetism & Induction

• Permanent & Temporary magnets

• Electromagnetic Fields

• Video - Electromagnetic Induction:

https://www.youtube.com/watch?v=hajIIGHPeuU

+_

7

AC Cycles and Phases

One Cycle of single phase AC shown as a sine wave

0 90 180

270

360

One Cycle of three phase AC shown as a sine wave

1 Phase 3 Phase

8

Motors & Generators

Video: http://www.youtube.com/watch?v=d_aTC0iKO68&feature=related

9

Power Plants10

Transformers

• Raise and lower voltages

• Have primary and secondary coils

• Provide electrical isolation

11

Electrical Terms

Ω

12

Water AnalogyVoltage

Current

Resistance

13

V = A x R W= V x A

W

V A

V

A R

Ohm’s LawOhm's Law states that one volt pushes one amp through one ohm of resistance

P or W = Power (expressed in watts) V or E = Voltage (expressed in volts)I or A = Amperage (expressed in amps) R = Resistance (expressed in ohms)

14

Some calculation examples:

Power (Watts) = Voltage x CurrentPower = 60 W Current = 5 Amps

Voltage = ???

Current (Amps) = Voltage / ResistanceVoltage = 120 VResistance = 10 Ω

Current = ???

15

Section 3 – Electrical Circuits

• Electrical Circuits

• Measuring Electrical Circuits

• Electrical Circuit Protection

16

Circuits

Series Circuit Parallel Circuit

17

Series Circuits

• Switch is controlling allthe lights in the circuit

• The two Push Buttons (PB) are in series with the light

• When either one is open,what happens?

S1

L1

R

L2

PB1 PB2

In a series circuit, there is only one pathway for current to flow

18

Parallel Circuits

L1

L2

L3

L4

L1 L2

S1

2

3

4

1

This example has 4 separate pathways for current flow.

In a parallel circuit, there are multiple pathways for current to flow

19

Open and Closed Circuits

L2

L1

L1

PB2

PB1

L2

• Push Button 1 (PB1) is open: The circuit is _____, the load is ______.

• PB2 is closed: The circuit is _____, the load is ______.

20

Safety Circuit (Ground Wires)

Ground wires are part of the safety circuit.

21

Short Circuits

• A short circuit is a circuit without a load and therefore low/no resistance.

• Current bypasses intended load – allows a high level of current flow in a circuit that exceeds rated amperage for the circuit (including human body!).

• High amperage causes overheating, damage, fires. • Circuit protection should open to prevent damage.

22

Circuit Protection

Circuit Breaker opens at specific temp. Fuses melt at specific temp.

Ground Fault Interrupter designed to prevent electrocution

23

Measuring Electricity

• Do not work on any electric equipment unless you are trained and qualified to do electrical work.

• Treat all circuits as if they were live.

• De-energize any circuit before working on it.

• Read and learn all safety procedures regarding the meter you use

• The two most common tools for Electrical Measurement: • Digital multimeter (DMM) • Clamp-On Ammeter.

24

Measuring Voltage• Volt measurements are taken in parallel.

• Voltage drop is voltage used at a load.

• Amperage measurements use clamp-on or line splitter attachments.

L2L1

Connect the volt meter in parallel with the component being tested.

Multi-Meter

https://www.youtube.com/watch?v=bF3OyQ3HwfU#t=17

25

AMPS = 0VOLTS = 120 AMPS = 10

RESISTANCE = 0

RESISTANCE = 2.5 OHMSAMPS = 10

V

VVOLTS = 0

VOLTS = 25

V

OPEN CONTACTS CLOSED CONTACTS

CLOSED CONTACTSPITTED & CORRODED

Measuring Voltage Source & Drop26

Measuring Current - AmpsClamp On Ammeter to measure current

Video: https://www.youtube.com/watch?v=z-KfZvbjyBY#t=18

Clamp-on Ammeter

27

Section 4 – Electrical Maintenance Issues

• Electrical Maintenance/Troubleshooting

• Exercise: Testing Transformers

• Voltage Irregularities

28

Electrical Maintenance / Troubleshooting

Scheduled Preventive Maintenance is covered in-depth in BOC Level 2.

In this class we will cover the most significant electrical maintenance procedures in the next few slides:

• Overheating circuits• No voltage to a circuit• Troubleshooting circuit breakers• Troubleshooting/testing fuses

29

Overheating Circuits

• Overloaded circuits are HOT

• Loose connections are HOT

• Corroded contacts are HOT

Maintenance:

• Scan all Breaker Panels once a year

• Exercise Breakers/Switches once a year

30

No Voltage to a Circuit

• Check circuit breaker or circuit fuses

• Find cause of blown fuse or tripped breaker

• If no breaker is tripped, check power into circuit breaker panel box

• Reset tripped breaker, replace fuses

31

Troubleshooting Circuit Breakers

• A good circuit breaker is in the On position

• A tripped circuit breaker is in the Middle or Off position

• Find the cause of the tripped breaker

• Breakers must be correctly labeled

• Trace circuits using circuit tracers

32

Troubleshooting & Testing Fuses

• A good fuse has continuity – nearly zero ohms.

• A blown fuse has no continuity – infinite resistance.

• Find the cause of the blown fuse.

• Replace a fuse by putting it into the load side first, then the line side (Note: Never replace a fuse in an energized circuit).

33

Testing a Transformer with Ohmmeter

H1 H2

X1 X3 X2 X4

W" OL" ; N O CON TIN U IT Y

W" OL" ; N O CON TIN U IT Y

W" OL" ; N O CON TIN U IT Y

CORRECT, OR �GOOD�OHM METER MEASUREMENTS (Multi-Meter is set to measure Ohms/Resistance)

34

Testing a Transformer with Ohmmeter

�BAD� OHM METER MEASUREMENTS

H1 H2

X1 X3 X2 X4

W" OL" ; N O CON T IN U IT Y

W" OL" ; N O CON T IN U IT Y

W

35

Voltage Irregularities & Variations

• Low voltage can cause operational problems.

• Increased amps can increase heat.

• 5% Voltage loss maximum acceptable.

Types:• Over- and under-voltages

• Disruptions

• Voltage surges/spikes – high

• Voltage dips – low

• Electric “noise” – Harmonics

36

Voltage and Phase Monitoring

• Voltage quality monitors

• Check for phase loss/ phase imbalance • Phase monitors

• Phase sequence reversal

• Maintain cooling equipment for power vault and panel boxes

37

Section 5 – Building Electrical Systems and Safety

• Building Electrical Systems• Overview• Components

• Electric Safety

38

Building Electrical Systems –Overview/Main Components

Sub-panels, ie. Circuit Breaker Panels: 1-Phase & 3-Phase Power

Loads in Building (HVAC, Motors, Lighting, etc.)

Main Distribution Panel / Power Vault

Incoming Service

Transformer Disconnect Switch Meter

39

M

480V 120/208V

TO LARGE LOADS

LARGE MOTORS

HIGH VOLTAGE PANEL

LOW VOLTAGE PANEL

MAIN DISTRIBUTION PANELL

BRANCH CKT

FEEDER

FEEDER

BRANCH

BRANCH

BRANCH BRANCH

M

Building Electrical Systems –Overview/Main Components (Illustration)

40

Service/Distribution & Control Transformers

• Service/Distribution Transformer • Dry Type or Liquid

Single Phase • Step-down: 480/240V or 240/120V• Rated Capacity: 15KVA• Limited Output: 15,000 Volt-Amps

Control Transformer:Supplies the control voltage inside the equipment

41

Main Distribution Panel / Power Vault42

Main Distribution Panel / Power Vault43

Breaker Panel – High Voltage• 208V / 270V / 480V • Three phase OR single phase • Large Motors

Breaker Panel – Low Voltage• 110V / 120V • Single phase only• Small loads: lights, plug loads, small equipment

Breaker Panels / Sub-Panels44

Voltage Phases

Single phase low voltage, single phase high voltage, three phase voltage.

45

Three Phase Panel

1 2357911131517

4681012141618

AF BF CF

NEUTRAL CONNECTION BARGROUND CONNECTION BAR

PANEL BUS BARSW/WIRE LUGS FOR

FEEDER CONNECTIONCIRCUIT BREAKERS

46

• Lighting • Plug Loads • Low Voltage Loads

Breaker Panel – Low Voltage47

Safety – working with electrical systems

• Work with a partner

• Let people know where you are working

• De-energize circuit

• Test circuit first

• Use lock-outs / tag-outs

• Never remove another person�s lock or tag

48

When to Call for Help…à ANY TIME YOU WANT TO!• If no power into circuit breaker panel box, check fuses

protecting the panel box.• If fuses are good, call in an electrician• Know where in the circuit to stop testing• Use test equipment safely

Electrical Standards• NEC - National Electrical Code• NEMA - National Electrical Manufacturer’s Association

Safety – working with electrical systems49

Review and Class Reading Assignments (Weeks 1 and 2)

What your reactions? Main learning points you gained from the first class?

Readings:§ BOC 107: to review Power Basics (this week, Week 1)§ HERZOG CH. 3 PP 29-50 (for next class)

50