AUTOMATIC TRANSFER SWITCHES - PowerPoint PPT Presentation

1 / 105
About This Presentation
Title:

AUTOMATIC TRANSFER SWITCHES

Description:

AUTOMATIC TRANSFER SWITCHES – PowerPoint PPT presentation

Number of Views:6345
Avg rating:3.0/5.0
Slides: 106
Provided by: deanva
Category:

less

Transcript and Presenter's Notes

Title: AUTOMATIC TRANSFER SWITCHES


1
(No Transcript)
2
A Common Straight Emergency Power System Scenario
R
3
Normal Operation
Commercial Utility Power
UPS System
Network Computer Loads
UPS Batteries
Cooling Lighting To Computers
R
Air conditioning, Lighting, Mechanical Loads, etc.
R
Generator Paralleling Control Switchgear
R
4
When Power First Fails
UPS System
Commercial Utility Power
Transfer Switchgear
Network Computer Loads
R
UPS Batteries
R
Air conditioning, Lighting, Mechanical Loads, etc.
R
Generator Paralleling Control Switchgear
Generators Then Feed Building Loads Through
Switchgear and Transfer Switches
5
System Automatically Returns to Normal Operation
Commercial Utility Power
UPS System
Transfer Switchgear
Network Computer Loads
R
UPS Batteries
Cooling Lighting To Computers
R
Air conditioning, Lighting, Mechanical Loads, etc.
R
Generator Paralleling Control Switchgear
R
6
AUTOMATIC TRANSFER SWITCHES
7
Definition
An Automatic Transfer Switch (ATS) is a, high
speed switching device designed to safely
transfer electrical loads from a power source to
an alternate power source upon reduction or loss
of voltage to retransfer to the original source
when power is restored.
R
8
ATS APPLICATIONS
Where does an ATS fit into a Building
Distribution System?
R
9
Unloaded engine cool down period
Utility is Restored
Load is fed by emergency power
Utility is Lost
Simple One-line, of ATS Transferring Between Utili
ty Generator
R
10
MAJOR COMPONENTS OF AN AUTOMATIC TRANSFER SWITCH
11
In an over center, (spring loaded design). The
mechanisms which drive the contacts utilize a
spring assisted motor operated concept. This
design provides for a quick-break, quick-make
operation, with full arc interruption, under
maximum voltage and amperage.
  • Over Center
  • Spring Mechanism

Initial Point of Contact
12

A Critical Component
Transfer Contacts
Russelectric 2000 ampere rated movable finger
contact assembly
R
13
Transfer Switch Controls...
Any PLC Controller should operate with an
industry standard open architecture communication
protocol for Windows compatible, high speed
serial communications via multi-drop connection,
fiber optic, or wireless to other controllers
and/or to a master terminal.
14
System settings should be performed locally,
through a menu driven touch screen or remotely,
to master terminal/s.
15
The Microprocessor (PLC) Controller is designed
specifically to be the central operating system
for Transfer Switches and will communicate with
any open architecture protocol device.
It is integrated into the hard wired circuitry.
Opto-Isolators carry signals between PLC logic
and traditional electro-mechanical controls.
16
FEATURES COMMON TO ALL RUSSELECTRIC TRANSFER
SWITCHES
  • UL LISTED through 4000 amperes for 2, 3, and 4
    pole configurations
  • Simple unidirectional motor operator
  • High-Speed transfer mechanism
  • Rapid arc quenching
  • Safe manual operator provides same instantaneous
    contact opening and
  • contact closing speed as electrical operator
    (on all open transition transfer
  • switches)
  • Positive mechanical and electrical interlocking
    (on all open transition
  • transfer switches)
  • 100 Continuous duty rated (6x for motor inrush)
  • The Industrys Highest 3-Cycle Close and
    Withstand Ratings
  • Open type (switchboard construction available)

17
Lets discuss 4 pole (switched neutral designs)
R
18
Fully Rated Switched Neutral
Before
  • (One Line of Neutral Bus. or, 4th pole)

(Same construction and withstand rating as the
main power poles)
19
Overlapping Neutral
(Other Approach)
Breaks
Before
Makes
(One Line of Neutral Bus or, 4th pole)
20
Switching inductive loads...
Dual Motor OperatedTransfer Switch
R
21
The load source is disconnected for an adjustable
period to allow regenerative power to decay
22
Transfer Switches with Bypass Isolation Overview
R
23
Bypass Isolation Switches
Definition
  • A manually operated device used in
    conjunction with a transfer switch to provide a
    means of directly connecting load conductors to a
    power source and of disconnecting the transfer
    switch.

R
24
Standards
  • The Applicable Standards are
  • ANSI
  • UL
  • IEEE
  • NEMA

R
25
Application
  • RTB(D) - Load Break Design Where a bypass
    isolation switch is required and simplicity of
    operation is critical during an emergency
    condition

R
26
Lets Talk Conceptually About Load Break No Load
BreakBypass Switches
Load Break Contacts
  • RTB(D) - Load Break design (Break-Before-Make
    Bypass)

If the transfer switch portion is bypassed
isolated to normal and the normal power fails an
engine start signal will initiate...
Emergency Power Available
Can rack back in no matter what position the ATS
is in.
Switch Bypassed to Emergency
LOAD BYPASSED TO NORMAL
R
27
Benefits of the Load Break Bypass Design
  • Power can be maintained to load during ATS
    failure
  • Provides a means of bypassing the ATS for
    maintenance
  • No elaborate system of electrical solenoids,
    electrical interlocks or mechanical interlocks
  • Fast, Simple and Easy Operation

R
28
Benefits of the No Load Break Bypass Design
  • Power can be maintained to load during ATS
    failure
  • Provides a means of bypassing the ATS for
    maintenance without load interruption

R
29
Operation (Load Break Bypass Switch)
  • 1. Observe - that the source is available
  • 2. Slide - the handle over to the
    desired/available source
  • 3. Pull - the bypass handle down
  • 4. Pull - isolating handle to isolate ATS

R
30
1. Observe - that the source is available
R
31
2. Slide - the handle over to the
desired/available source
and 3. Pull - the bypass handle down
R
32
4. Pull - isolating handle to isolate ATS
R
33
Rack-out - Remove ATS if desired
R
34
If Normal Source is lost while Isolated or Racked
out - Engine start signal will automatically be
given. When Emergency source is available,
bypass to Emergency
R
35
Slide Bypass Handle over to Emergency
R
36
Pull Down Bypass Handle to Emergency
R
37
Important Construction Features
  • 12-gauge steel enclosure
  • Plenty of cable bending space
  • No aluminum bus or components
  • Bus connections - Belleville type compression
    washers
  • Self-aligning ATS draw-out
  • Maintain Engine Start on Bypass to Emergency

R
38
Russelectric ATS Ratings,3-Cycle Close and
Withstand
  • 100 - 400 Ampere 42,000 Amps
  • 600 - 800 Ampere 65,000 Amps
  • 1000 - 1200 Ampere 85,000 Amps
  • 1600 - 4000 Ampere 100,000 Amps

R
39
Additional Power Monitoring (Upgrade)
  • AC Power Monitor
  • Transducer Section
  • Protective Relay Section

40
Power Monitoring cont.
  • AC Power Monitor

Transducer Section
  • True RMS voltage measurement of each phase of
    both the normal and
  • emergency sources
  • Frequency of both sources
  • True RMS current of each phase
  • Power factor relative to either voltage source
  • Phase sequence of each source
  • True and reactive power consumption

41
  • AC Power Monitor

Protective Relay Section
  • Undervoltage and underfrequency sensing of each
    source
  • Overvoltage and overfrequency sensing of each
    source
  • Phase reversal protection of each source
  • Voltage differential protection of each source
  • Synchronizing check between the normal and
    emergency sources

42
Power Monitoring cont.
  • Power Monitoring
  • Historical Data
  • Logs the last 100 events
  • No more codes
  • Serial Communications

43
  • Power Monitoring Control Screen
  • ModBus Communications

Amperes
Emergency Voltage
Normal Voltage
KW, Kvar, KVA, PF
First Status Screen
  • Historical Data
  • Logs the last 100 events
  • In English No more codes

44
ATS Control Screens, Ethernet, Fiber Optic or Web
BasedMain Screen
R
45
Example Normal Real Time Trend(Shown
flat-lining)
R
46
Power Monitoring cont.
  • Power Monitoring
  • Historical Data
  • Serial Communications
  • Plugs directly into Microprocessor

47
Generator Control Switchgear
48
Types of Systems
Emergency Systems
  • Peak Shave
  • Utility Parallel
  • Cogeneration

Prime Power Systems
49
Types of Operational Modes
  • Open Transition
  • Closed Transition

R
50
Open Transition Mode
An open transition mode of operation is a method
of transferring a load between two sources with
an interruption of power during the transfer.
R
51
(No Transcript)
52
Load Control
Load priority - The load priority scheme in an
emergency system is based upon the number of
engine generators.
Load shed - Failure of an engine generator
causes the lowest priority level load to be shed.
Load shed bypass - Manually override the load
shed control so that a previously shed load can
be re-added even though the emergency system
does not have all of the engine generators
available.
Load Demand - The number of engine generators
required to be on line is based upon the bus
kW.
R
53
Closed Transition Mode
A closed transition mode of operation is a
method of either
1) Transferring a facilitys load between the
utility and generator or 2) operating a generator
in continuous parallel with the utility service,
without an interruption of service.

R
54
R
55
Why Would A Facility Prefer a Closed Transition
Mode of Operation?
  • Desire not to interrupt loads during
    transfers back to the utility after a power
    outage
  • Participation in a Utility sponsored load
    reduction program

R
56
Advantages of a Switchgear Controlled Closed
Transition Mode of Operation
  • Active phase lock synchronization of generator to
    the utility
  • Gradual transfer of load between utility and
    generator eliminating unwanted system transients
  • Utility involvement and approval
  • Protection of each source from the other while
    paralleled

R
57
2 Common Classes of Switchgear Manufactured
  • Low Voltage Switchgear
  • 600 VAC and below
  • Medium Voltage Switchgear
  • 5 kV, 15 kV and 27 kV
  • Equipment Should be Manufactured to the
    following Standards ANSI, NEMA, UL
  • All Equipment Should be listed and labeled in
    UL under the Manufacturers name

R
58
Low Voltage Switchgear
  • Metal enclosed construction
  • Two UL Standards apply
  • 891
  • 1558
  • Bus sizes 1000 through 10,000 amperes
  • Two bus bracing ratings
  • 100 kA
  • 200 kA

R
59
UL 891
UL 1558
4000A Rated Bus - UL 891
4000A Rated Bus - UL 1558
  • UL 1558 Switchgear Construction
  • Built To UL Std. 1558
  • The Most Robust In Terms Of Bus
  • Work, Bracing, Insulation, And
  • Short Circuit Withstand
  • Rated Tested For 200,000 AIC
  • Short Circuit Withstand
  • Switchgear Bus Construction
  • Built To UL Std. 891
  • Less Robust Construction
  • Rated (but not tested) For 65,000 AIC
  • Short Circuit Withstand

60
UL 891
UL 1558
4000A Rated Bus - UL 891
4000A Rated Bus - UL 1558
61
More on Construction - Metal Enclosed
  • Voltages up to 600 VAC
  • Insulated main bus not required
  • Insulated bus joints not required
  • Circuit breakers can either be fixed mounted
    or draw-out
  • Draw-out breakers can have exposed cradle
    stationary contacts when the breaker element
    is removed
  • PTs are fixed mounted in main bus compartment

R
62
Medium Voltage Switchgear
  • Metal - clad construction
  • UL Standard for Metal-Clad switchgear over
    600 VAC DLAH Standard for Metal Clad Swgr.,
    over 600 Volts
  • Bus sizes 1000, 2000 3000 amperes
  • Bus braced for 1000 MVA

R
63
More on Construction - Metal Clad
  • Voltages above 600 VAC
  • Insulated main bus
  • Insulated bus joints
  • Circuit breakers must be draw-out
  • Circuit breakers must have shutters to barrier
    cradle stationary contacts when the breaker
    element is removed
  • PTs required to be draw-out with automatic
    disconnect means or fixed mounted in an
    isolated compartment accessible only after power
    removed

R
64
More on Construction - Metal Clad
R
65
More on Construction - Metal Clad
R
66
More on Construction - Metal Clad
R
67
Critical Facilities and Built in Redundancy
68
Does Your Back-up System Have a Back-up System?
69
Important Questions Considerations
Cost, in terms of life safety or financial loss,
as the result of a catastrophic power failure.
In the case of healthcare, you may be thinking
One can never put a price on life and limb
Or in the case of protecting data, you may be
thinking The cost of an outage would far
exceed that of any price differential in
emergency equipment, or maybe even the cost of
an entire system
Up-front cost of Original Equipment is a Major
Consideration
70
When considering the criticality of protecting
facilities from power outages, its prudent to
be aware of the differences in design
philosophies between the various manufacturers of
emergency power equipment.
71
Depending on the facility, a power control system
which provides full manual back-up to insure a
means for controlling the system in the event of
complete PLC failure my be a wise choice.
Let us consider the importance of redundant
Digital Control
72
Dual Redundant PLCs, running in tandem(Hot
Back-up)
With Separate and Distributed I/O Rack in the
Master Cubicle
73
Why is Full Manual Back-up important?...
74
In complex and critical applications, where you
may someday be reduced to relying on pure manual
control as a result of a major failure, you
really need an isolated, hardwired fully
independent means to be able to perform all
functions manually.
Its vital to be able to
  • Be in a quiet area, away from engine noise to
    calmly navigate your system through a crisis
    period.
  • Be able to control engines Start them, get them
    synchronized and paralleled to the Emergency Bus
    Perform Load Shed, load add functions
  • Be able to control the system as it relates to
    the Utility side of the infrastructureUtility
    paralleling, metering, tie breaker control, etc.

75
Please be aware that
  • Some manufacturers offer packages with no means
    of hardwired manual back-up.
  • Some offer full manual back-up, but only outside
    of their standard package.
  • Some offer semi manual back-up, where some
    functions and controls are hardwired, with
    metering remaining digital (virtual).

76
Typical Control Package
  • Navigation Screen
  • System Oneline
  • System Legend
  • ATS Oneline
  • Transfer Controls
  • Transfer Control Help
  • Engine Setpoints and Status
  • Engine Setpoints and Status Help
  • Engine Metering
  • Generator Demand
  • Generator Demand Help
  • Load Control Setpoints
  • Load Control Setpoints Help
  • Load Priorities
  • Load Priorities Help
  • System Information
  • Programmed Alarms

R
77
(No Transcript)
78
SCADA
  • SYSTEM
  • CONTROL
  • AND
  • DATA
  • ACQUISITION

79
Consider any Existing Site CriteriaBefore
Developing the SCADA System
80
An active one-line for system simulation and/or
control.
81
To follow are Various SCADA examples
82
System One-Line
Fully Customizable to your Preference, Line
Weights, Colors Graphics
From Simple...
83
To Complex
84
Or More Complex!
85
Example
86
Example
87
Example
88
Not All SCADA is the Same, so Our Designs Meet
all Requirements.
89
Active Alarm Legend
Active alarms show Real-time High Priority
Situations that need to be Rectified Immediately
90
Alarm Event History
Event History Configurable Log File stored on
computer hard drive for 365 days, very useful for
problem diagnostics.
91
Setpoints Pop-up Screen
Password Protected
Setpoints are Adjustable
Timers Give Actual Values
Write Back to PLC
92
Historical Trending
93
Trending Files Also Stored on Hard Drive for
Later Review 24 hour Load Demand Trending
94
Display Priority Screen
95
Communications Screen 1
96
Communications Screen 2
97
Switchgear Elevation
98
Control Room Elevation
99
Critical Distribution Elevation
100
Substation Elevation
101
UPS Elevation 1
102
Controls Zoom In 1
103
Controls are password protected and display or
control plant status and operations.
Real Time Functionality
104
Web View for Remote Access Operation of Plant
-Password Protected- (Web
Access Suite Voyagertm)
105
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com