building electrical and signal system
DESCRIPTION
Building Electrical and Signal SystemTRANSCRIPT
1
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 1
BUILDING ELECTRICALAND SIGNAL SYSTEMS
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 2
Electricity – Background
• Electric charge was known to the ancient Greeks• Magnetism was known historically via observation• A link between electric and magnetic phenomena
was noted in the 1820s• Maxwell’s equations/physics in the late 1800s• The first use of electricity in buildings was also in
the late 1800s (Edison and Tesla played a role)• The impact of electricity was phenomenal – it
radically changed building design
2
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 3
Residential BuildingTransformation
Pre-electric(and pre-mechanical) >>
Post-electric(and post-mechanical) >>
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 4
Office Building Transformation
Pre-electric Post-electric
(daylit and naturally ventilated) (electric lighting and HVAC)
predominantlyexterior space
predominantly interior space
3
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 5
Static Electricity
• Involves a charge accumulation and subsequent discharge
• Intermittent current flow (as in lightning or static shock)
• Limited building applications
• Nature’s attempt to increaseentropy (disorder)
faculty.clintoncc.suny.edu
nimrod.phy.uc.edu
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 6
Dynamic Electricity
• Involves a consistent flow of electric current
• Limited examples in natural systems (galvanic action is one)
• Vast potential in human-made systems
4
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 7
Electric Current
• Represents a flow of charge through an appropriate medium (a conductor)
• Moves at the speed of light (electricity is a form of electromagnetic radiation)
• DC = direct current (as with battery-driven devices, photovoltaics)
• AC = alternating current (as with public and private utilities)
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 8
Direct Current (dc)
involves a continuous andconsistent flow of current through a circuit
5
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 9
Alternating Current (ac)
involves a cyclic flowof changing current through a circuit
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 10
Circuits
• Series circuit loads are an integral part of the network of conductors
• Parallel circuit there are multiple paths for current (flow can bypass any individual load)
parallel circuits predominate in building power distribution systems
6
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 11
Circuits
www.berkeleypoint.com/
series
parallel
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 12
Electrical Circuit Properties
• Voltage analogous to water pressure, it represents the difference in “potential” between points on a circuit, voltage is the driving force for current flow
Volts (V)
• Amperage analogous to water flow rate, it represents the volume of electron flow; amperage is often used as a measure of circuit capacity
Amps (A) (1 amp = 6 x 1018 electrons/sec)
7
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 13
Electrical Circuit Properties
• Resistance analogous to friction, it accounts for energy lost due to electron flow through an imperfect conductor (no free lunch, entropy); electrical resistance is proportional to flow
Ohms (Ω)
• Wattage represents the combined effect of voltage and amperage (wattage is a measure of the potential for work)
Watts (W) W = (V)(A)
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 14
Electrical Circuit Properties
• Frequency a measure of the cycling pattern in an alternating current circuit (North American frequency is 60 Hz; Europe is often 50 Hz)
Hertz (Hz) Hz = cycle per second
• Power factor represents the phase relationship between voltage and amperage in a circuit (high is good, low is bad … and low may incur penalty charges from a utility)
PF (a decimal value)
8
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 15
Residential Voltage Standards
120 volt, 2 wire, 1 phase
120/240 volt, 3 wire, 1 phase
120 V is used for plug loads; 240 V for large appliances
from a physics perspective, voltage can be any value desired; from a practical perspectivedistribution voltage should match the operating voltage of connected appliances
only 120 V is available for loadshot
neutral
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 16
Non-Residential Distribution Voltage Standards
277/480 volt, 4 wire, 3 phase
120/208 volt, 4 wire, 3 phase
480 V is used for large motors; 277 V for some fixed lighting and/or motors
277
9
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 17
Power Factor
resistive loads non-resistive loads(incandescent lamps, (fluorescent lamps,
electric heaters) motors)
www.pittjug.org/
e = voltage, i = current; p = power; note decrease in magnitude of power curveon the right (for the same voltage and current)
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 18
Energy and Power
• power = instantaneous work (now!)kilowatts (kW)
• energy = work integrated over timekilowatt-hours (kWh)
• utilities often charge for both of these via an energy charge (for kWh) and a demand charge (for peak kW)
• other “tariffs” include time-of-day pricing, sliding scale pricing, and interruptible service pricing
a tariff is a utility’s rate structure
10
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 19
tarif
fs
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 20
the
list g
oes
on a
nd o
n
tarif
fs
11
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 21
Ene
rgy
and
Pow
er
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 22
Ene
rgy
and
Pow
er
12
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 23
Energy and Power
Power
Energy
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 24
Matching Energy and Power (for PV)
Power
Energy
13
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 25
Electricity and Building Design
• Electricity is a very high quality form of energy (it has low entropy) that has hundreds of uses (heating, cooling, computers, motors, toasters, TVs, …)
• Electrical safety caused the development of the first firecode (the National Electrical Code >> NFPA)
• Codes, standards, listings:
– NEC [typically enacted as a code]
• minimum system and equipment requirements
– ASHRAE 90.1 [a standard, often enacted as a code]
• a few electrical energy constraints
– UL [a “listing” incorporated into codes]
• product listings; everything must be listed
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 26
Building Electrical Systems
• Include service components– concerned with getting electricity “into” a building
safely and in a usable form (the local utility company and the design team make service decisions)
• Include distribution components– concerned with getting electricity safely where it is
needed within a building (the design team determines what is appropriate relative to distribution—within the constraints of the NEC)
• Include load components– the things that consume electricity (the owner and
design team determine loads)
14
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 27
Electrical System Block Diagram
utility
PV?
tf = transformer; sg = switchgear; ep = emergency power; mcc = motor control center; lp = lighting panel; pp = power panel
Receptacles
Luminaires
service distribution loads
the
serv
ice-
dist
ribut
ion
boun
dary
is n
egot
iabl
e on
a p
roje
ct-b
y-pr
ojec
t bas
is
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 28
Building Electrical System One-Line Schematic Diagram
some examples of service components follow >>
15
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 29
Service Location Planning
plan for location andsize of electrical spacesapx. 1% of floor area for main electrical room
mechanical room
electrical room
shop
service
an example of goodspatial planning
large loads (mechanical and shop equipment) are adjacent to electrical room
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 30
Transformers
internal step-down
external, utility
external, building service
purpose: to change voltage (usually to reduce V)
16
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 31
Switchgear
purpose: meter, control, monitor power flow
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 32
Emergency Power
dieselgenerator at ahospital; withundergroundfuel tank
architecturally …is this acceptable?is such equipment just“invisible”?
purpose: to provide power during an outage of the utility source
17
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 33
Building Electrical System One-Line Schematic Diagram
some examples of distribution components follow >>
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 34
Distribution: Using “Open” Channels raised access floor
this links to UFAD
18
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 35
Distribution: Using Closed Channels
conduit
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 36
Distribution: Using Closed Channels
cellular metal deck (used as “structure” and electrical channel)
19
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 37
Distribution: Using Packaged Systems
surface raceway
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 38
Building Electrical System One-Line Schematic Diagram
some examples of load components follow >>
20
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 39
Fixed Loads (Motors)
escalators, elevators, fans,pumps, chillers, cooling towers,air-handling units, fan-coil units, etc.
hard wired
fixed loads are essentially “bolted down” and aresized by the design team
HOBO datalogger
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 40
Plug Loads
conveniencereceptacles for movable stuff …. you name it
building lighting loads have been steadily reduced over the past 15 years, while plug loads have increased by like magnitude
21
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 41
Building Signal Systems (they are numerous and diverse)
• telephone• data• fire alarm• energy and/or building management
– most larger buildings have EMS, BAS, or BMS: energy management system, building automation system, building management system (different terms for similar systems)
– “smart buildings” on the horizon?• security• sound (background, ambience, music)• master clock• closed circuit or cable TV ….
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 42
Signal System Characteristics
• usually involve dedicated (sole-use) distribution lines for each system
• systems are often proprietary (secret stuff, not specified in detail)
• systems are often low voltage (allowing for fairly flexible distribution)
• rapid change is often necessary (demanding easy access and flexibility)
• key design issues:– access, access, access (for maximum flexibility)– performance specifications will be involved if system is
proprietary– architectural coordination (with, for example, fire zones)
22
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 43
Typical Signal System Schematic
service panel orcomputer devices
site boundary
information flow
“signal” systems typically involve communications and data
Ball State Architecture | ENVIRONMENTAL SYSTEMS 2 | Grondzik 44
Typical Signal SystemBlock Diagram
sensor or interface device(smoke detector, motion detector, thermostat, photosensor, etc.)
panel or computer(for making “if … then”decisions)
activated device(fire alarm, fan control, VAV box, computer display, etc.)