Download ZBTSD SERIES Guideform Spec.

ZBTSD SERIES
Delayed Transition Transfer Bypass/Isolation Switches
An automatic transfer switch shall be furnished as specified herein.
1
GENERAL
1.1
The transfer switch shall be rated for the voltage and ampacity as shown on the plans and shall
have 600-volt insulation on all parts in accordance with NEMA standards.
1.2
The current rating shall be a continuous rating when the switch is installed in an unventilated
enclosure, and shall conform to NEMA temperature rise standards.
1.3
The unit shall be rated based on all classes of loads, i.e., resistive, tungsten, ballast and inductive
loads. Switches rated 400 amperes or less shall be UL listed for 100% tungsten lamp load.
1.4
As a precondition for approval, all transfer switches complete with accessories shall be listed by
Underwriters Laboratories, under Standard UL 1008 (automatic transfer switches) and approved
for use on emergency systems.
1.5
The withstand current capacity of the main contacts shall not be less than 20 times the
continuous duty rating when coordinated with any molded case circuit breaker established by
certified test data. Refer to the required withstand and close ratings as detailed in this specification.
1.6
Temperature rise tests in accordance with UL 1008 shall have been conducted after the
overload and endurance tests to confirm the ability of the units to carry their rated currents
within the allowable temperature limits.
1.7
Transfer switches shall comply with the applicable standards of UL, CSA, ANSI, NFPA, IEEE
and NEMA.
1.8
The transfer switches shall be supplied with a microprocessor based control panel as detailed
further in these specifications.
1.9
The microprocessor and all related control systems are housed in a separate compartment that
will permit all customer connections to be terminated in an enclosed chamber free of high
voltage / high current connection terminals. This isolated compartment shall be comprised of
strictly low voltage devices and connection points. All connections will be intended for low
voltage / low current feed and shall be clearly marked for ease of use. Every connection point
will be equipped with screw terminals and will not permit for bare wire connections.
1.10
A bypass-isolation transfer switch shall be provided to permit convenient manual electrical
bypass and isolation of the automatic transfer switch that could not otherwise be tested,
inspected and maintained without interrupting the load. Bypass of the load to either the normal
or emergency power source with complete isolation of the automatic transfer switch shall be
possible regardless of the status of the automatic transfer switch. The bypass-isolation switch
shall permit proper operation by one person through the movement of a separate handle. The
entire system shall consist of two elements: the automatic transfer switch and the bypassisolation switch furnished completely factory interconnected and tested.
1.11
The construction of the Automatic Transfer Switching device shall be such that the current
carrying contacts are fully enclosed to prevent external arc flashes yet constructed such that
they can be easily accessed for visual inspection and replacement if necessary. It is desired
that access to these contacts be directly from the front of the ATS without the need to remove or
disassemble major components or devices within the bypass design.
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Date: December 11, 2008
1.12
A bypass-isolation transfer switch shall be provided with the features necessary to allow for
isolation of the Automatic Transfer Switch via external means without the need to access the
current carrying components of the device. All transitional motion of the Automatic Transfer
Switch (Auto / Test / Isolate) shall be accomplished via external means without the need to open
the main enclosure door. Included in this requirement is the ability to store all operating handles
in a separate compartment that is free and away from the line voltage / line current carrying
elements. To ensure that only qualified personnel can access the internal live, the design shall
be such that all operating handles may be stored and locked in this compartment if
required/desired by building/local facilities management.
1.13
A bypass-isolation transfer switch shall be equipped with an automatic shutter system that will
automatically open and close upon installation and removal of the Automatic Transfer Switch
portion of the system. The system shall behave in such a manner that will prevent incidental
contact with all live bus systems via a moving shutter. During Automatic operation, the shutter
system shall remain open allowing for electrical connection between the Automatic Transfer
Switch and the Bypass assembly. In Test Mode, the shutter system will automatically adjust,
isolating the live bus from the automatic transfer switch. This will ensure a safe operation of the
Automatic Transfer Switch with zero current passing through the main contact assemblies. In
the Isolate Mode, once again the shutter system will remain closed, isolating the live bus from
the automatic transfer switch. Upon removal of the Automatic Transfer Switch from the
assembly, there shall be no access or exposure to live bus systems and no risk of accidental or
incidental contact between the live bus and the maintenance personnel. The design of this
system shall be such that it will provide maximum protection against fault conditions that may
occur on the front or rear panels of the bypass assembly.
1.14
To minimize installation and maintenance activities, the interaction between the front (ATS) and
rear (BPI) panels should be smooth and consistent with no unreasonable effort required to realign the bus systems or other features within the front or rear panels. This applies to new
installations as well as replacement of the automatic transferring device relative to the rear
panel. Should a spare Automatic Transfer Switch of like ratings be available and need to be
installed to replace a damaged unit or device, the installation shall be consistent with the
standard operating instructions without the need to readjust components or features within the
front or rear panels.
1.15
The operating speed of the bypass-isolation switch contacts shall be independent of the speed
of operation of the bypass handle.
1.16
The isolation handle shall provide three positions: Automatic, Test and Isolate. The Test position
shall permit electrical testing of the automatic transfer switch without disturbing the load. The
Isolate position shall completely isolate the transfer switch from both sources and load without
actual removal of the line or load conductors and allow its removal for inspection and maintenance.
The transfer switch shall be arranged for draw out operation to facilitate its removal. Also, while in
the Test or Isolate positions, the bypass-isolation switch shall function as a manual transfer
switch to allow load transfer to either source of power, regardless of the position or condition of
the transfer switch, including the condition when the transfer switch is removed, and without
reconnecting the load terminal of the transfer switch.
1.17
The load shall not be interrupted during bypass-isolation functions. The addition of load-break
contacts that cause load interruption is not acceptable. The bypass-isolation switch contacts
shall not be in the system current path except during actual bypass operation.
1.18
The bypass-isolation transfer switch shall be furnished with a detailed step-by-step operating
instruction plate, located outside on cabinet door, as well as the following function diagnostic
lights:

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Normal source available
ZBTSD Series ATS - Page 2
Date: December 11, 2008









Emergency source available
Bypass switch in normal position
Bypass switch in emergency position
Automatic transfer switch in test position
Automatic transfer switch isolated
Automatic transfer switch inhibit
Automatic transfer switch operator disconnect switch "OFF"
Automatic transfer switch in normal position
Automatic transfer switch in emergency position
1.19
The bypass-isolation switch shall be equipped with an independent engine start circuit so that,
should a utility outage occur while in the bypass-normal/ATS isolated condition, the engine will
automatically start and allow immediate selection of emergency bypass.
1.20
For ease of cable / bus connections, the design shall be such that it permits access to both
sides and rear of the enclosure. This will ensure adequate workspace and access for
connections during installation and maintenance
1.21
To ensure maximum system capabilities, the device shall be provided with means necessary to
accommodate up to 8 cables of 750 MCM for maximum current carrying capacity. This
capability shall be in the form of traditional mechanical lugs or approved compression lugs
depending on the local system requirements.
1.22
For those applications where front connection is required, the design shall permit for the
addition of components and supports necessary to make the appropriate connections within. It
will be permissible for additional compartments to be added to the base design such that all
bussing requirements fit within the enclosure of the device and yet meet all UL, CSA, IEC, and
NEC standards. Specific sizes for these add-on compartments shall be provided at the time of
request.
1.23
To ensure that foreign objects or debris does not fall onto the Automatic Transfer Switch or any
moving parts there within, the design should provide shrouds or other barriers to protect the bus
system and moving parts. This shroud or barrier device should be an integral part of the
product design and should not have to be removed or reinstalled prior to commissioning the
equipment. These barriers should be a permanent part of the design as debris may fall onto the
unit at any point during the life of the product.
1.24
The complete bypass-isolation transfer switch shall be tested to ensure proper operation of the
individual components and correct overall sequence of operation and to ensure that the operating
transfer time, voltage, frequency and time delay settings are in compliance with the specification
requirements.
1.25
The equipment shall be constructed for use in seismically vulnerable areas and certified for
compliance with the seismic requirements in this specification. The equipment provider shall
submit details of the required installation, including supports, anchors, and restraints. The
equipment provider shall submit a Certification Document, stamped by a licensed Professional
Engineer, stating compliance of the submitted equipment to the following parameters:
a) Certification to IBC 2006 & IEEE STD 693-2005 (covering Moderate and High
levels).
b) Peak Design Spectral Response Acceleration (Sds) = 3.6g
c) Spectral Response (% of g) = 300%
d) Importance Factor (Ip) = 1.5, with operation defined as transferring from the
primary to the alternate supply during the simulated event.
e) Site Class D
f) Applicable for mounting at any location in the building, with z/h = 1.0
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Date: December 11, 2008
2
1.26
The bypass-isolation transfer switch shall be the product of one manufacturer and completely
factory interconnected and tested so that only the services and load connections to the bypassisolation switch are required for field installation. All interconnections between the transfer switch and
the bypass-isolation switch shall be silver-plated bus bar. A visual position indicator shall be provided
to indicate bypass-isolation switch positions. Enclosure construction shall be in accordance with
UL and NEMA standards for industrial controls.
1.27
In the event that the Automatic Transfer Switch needs to be removed from the enclosure, the
design shall provide for several options to complete this task. Included in these options are
optional ramps that can be temporarily affixed to the front of the unit or optional carts/dollies that
can be wheeled right up to the unit for the easy transfer of the ATS from the enclosure to the
rollaway cart assembly. This will ensure an easy and safe removal of the ATS without the need
to create inclined ramp assemblies.
SEQUENCE OF OPERATION
2.1
The ATS shall incorporate adjustable three phase under and over-voltage and three phase
under and over-frequency sensing on the normal source.
2.2
When the voltage of any phase of the normal source is reduced to 80% or exceeds 110%
nominal voltage, or frequency is displaced 2 Hz from nominal, for a period of 0-10 seconds
(programmable) a pilot contact shall close to initiate starting of the engine generator.
2.3
The ATS shall incorporate adjustable three phase under and over-voltage and three phase
under and over-frequency sensing on the emergency source.
2.4
When the emergency source has reached a voltage value within +/- 10% of nominal and
achieved frequency within +/- 5% of the rated value, the load shall be transferred to the
emergency source after a programmable time delay.
2.5
When the normal source has been restored to not less than 90% of rated voltage on all phases,
the load shall be re-transferred to the normal source after a time delay of 0 to 30 minutes
(programmable). The generator shall run unloaded for 5 minutes (programmable) and then
automatically shut down. The generator shall be ready for automatic operation upon the next
failure of the normal source.
2.6
If the engine generator should fail while carrying the load, retransfer to the normal source shall
be made instantaneously upon restoration of proper voltage (90%) on the normal source.
2.7
Inspection and operational tests shall be conducted by the contractor in the presence of the
engineer, to indicate that the switch satisfies the specifications.
2.8
The transfer switch shall be equipped with a microprocessor based control panel. The control
panel shall perform the operational and display functions of the transfer switch. The display
functions of the control panel shall include ATS position and source availability.
2.9
The digital display shall be accessible without opening the enclosure door and shall be provided
with a 4 line by 20 character LCD display screen with touch pad function and display menus.
The programming functions shall be pass code protected.
2.10
The control panel shall be provided with menu driven display screens for transfer switch
monitoring, control and field changeable functions and settings.
2.11
The control panel shall be opto-isolated from electrical noise and provided with the following
inherent control functions and capabilities:
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Date: December 11, 2008
2.12
3
a.
Multipurpose display for continuous monitoring and control of the ATS functions and
settings. All field changeable functions shall be pass code protected and accessible
through the keypad.
b.
Built-in diagnostic display that includes the capturing of historical data, such as number
of transfers and time on emergency power source, for ease of troubleshooting.
c.
Capability for external communication and network interface.
d.
Touch pad test switch with Fast Test/Load/No Load positions to simulate a normal
source failure.
e.
Time delay to override momentary normal source failure prior to engine start. Field
programmable 0-10 seconds (adjustable by increments of 0.1 second) factory set at
3 seconds.
f.
Time delay on retransfer to normal source, programmable 0-60 minutes (adjustable by
increments of 0.1 minute) factory set at 30 minutes. If the emergency source fails during
the retransfer time delay, the transfer switch controls shall automatically bypass the time
delay and immediately retransfer to the normal position.
g.
Time delay on transfer to emergency, programmable 0-5 minutes, factory set at 1 second.
h.
Time delay on transfer in either direction in the center-off position, programmable 0-10
minutes (adjustable by increment of 1 second), factory set at 5 seconds.
i.
Terminals for remote test/peak shave operation and transfer inhibit to the emergency source.
j.
Auxiliary contacts (1 N.O.) shall be provided to indicate normal and emergency source
availability.
k.
A load/no load clock exerciser shall be incorporated within the microprocessor and shall
be programmable to start the engine generator set and transfer the load (when selected)
for exercise purposes on a weekly basis. The exerciser shall contain a lithium battery for
memory retention during an outage.
l.
A timed auxiliary contact (1 N.C.) adjustable 0-60 seconds shall be provided to allow
motor loads to be disconnected prior to transfer in either direction.
m.
Provide a momentary pushbutton to bypass the time delays on transfer and retransfer
and programmable commit/no commit control logic.
Note to Specifier: Please see attached list of additional accessories available (found under
SPECIFIER NOTES #2) and insert in this section as required.
CONSTRUCTION AND PERFORMANCE
3.1
The automatic transfer switch shall be a double throw switch operated by a reliable dual
electrical mechanism momentarily energized.
3.2
The transfer switch shall incorporate a timed, center-off position for motor load decay. Transfer
time shall be adjustable from 0-10 minutes. A mechanical interlock shall be provided to ensure
that both sets of contacts cannot be closed at the same time.
3.3
For switches installed in systems having ground fault protective devices, and/or wired so as to
be designated a separately derived system by the NEC, a 4th pole shall be provided. This
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ZBTSD Series ATS - Page 5
Date: December 11, 2008
additional pole shall isolate the normal and emergency neutrals. The neutral pole shall have the
same withstand and operational ratings as the other poles and shall be arranged to break last
and make first to minimize neutral switching transients. Add-on or accessory poles that are not
of identical construction and withstand capability are not acceptable.
3.4
The contact structure shall consist of a main current carrying contact that is a silver alloy with a
minimum of 50% silver content. The current carrying contacts shall be protected by silver
tungsten arcing contacts on all sizes above 400 Amps.
3.5
The transfer switch manufacturer shall submit test data for each size switch, showing it can
withstand fault currents of the magnitude and the duration necessary to maintain the system
integrity. Minimum UL listed withstand and close into fault ratings shall be as follows:
Size (Amps)
Up to 400
401 - 1200
1201 - 4000
Any Molded Case Breaker*
(RMS Symmetrical)
35,000
50,000
100,000
Size (Amps)
Up to 400
401 - 800
801 - 1200
1201 - 4000
Specific Coordinated
Molded Case Breaker
50,000
65,000
85,000
100,000
Size (Amps)
Up to 4000
Current Limiting Fuse
200,000
*
All values 480 volt, RMS symmetrical, less than 20% power factor.
3.6
A dielectric test at the conclusion of the withstand and closing tests shall be performed.
3.7
The automatic transfer switch manufacturer shall certify sufficient arc Interrupting capabilities for
operation between a normal and emergency source that are 120 degrees out of phase at 480
volts, 600% of rated current at .50 power factor. This certification is to ensure that there will be
no current flow between the two isolated sources during switching.
Size (Amps)
Up to 1600
1601-2500
2501 and above
Number of cycles of operation
50
25
3
3.8
All relays shall be continuous duty industrial type with wiping contacts. Customer interface
contacts shall be rated 10 amperes minimum. Coils, relays, timers and accessories shall be
readily front accessible. The control panel and power section shall be interconnected with a
harness and keyed disconnect plugs for maintenance.
3.9
Main and arcing contacts shall be visible without major disassembly to facilitate inspection and
maintenance.
3.10
A manual handle shall be provided for maintenance purposes with the switch de-energized. An
operator disconnect switch shall be provided to defeat automatic operation during maintenance,
inspection or manual operation.
3.11
The switch shall be mounted in a NEMA 1 enclosure unless otherwise indicated on the plans.
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ZBTSD Series ATS - Page 6
Date: December 11, 2008
3.12
Switches composed of molded case breakers, contactors or components thereof not specifically
designed as an automatic transfer switch will not be acceptable.
3.13
GE Zenith’s shall protect the automatic transfer switch for a period of 2 years, parts and labor
warranty or the equivalent.
3.14
The automatic transfer switch must be equipped with a solenoid protection scheme that
removes any attempts of operating the solenoids after (3) consecutive trials until manual
intervention by an operator.
3.15
The automatic transfer switch shall be GE Zenith ZBTSD Series or approved equal.
SPECIFIER NOTES:
1.
ZBTSD switches are in conformance with the applicable portions of:
UL 1008:
Underwriters Laboratories standard for automatic transfer switches
CSA:
C22.2 No. 178 certified at 600 VAC
IEC:
947-6-1 certified at 480 VAC
NFPA 70:
National Electrical Code including use in emergency and standby systems in
accordance with Articles 517, 700, 701, 702
NFPA 99:
Essential electrical systems for health care facilities
NFPA 101:
Life safety code
NFPA 110:
Standard for emergency and standby power systems
IEEE 241:
I.E.E.E. recommended practice for electrical power systems in commercial
buildings
IEEE 446:
I.E.E.E. recommended practice for emergency and standby power systems
NEMA ICS10:
AC automatic transfer switch equipment (supercedes ICS2-447)
UL 50/508:
Enclosures
ICS 6:
Enclosures
ANSI C33.76:
Enclosures
NEMA 250:
Enclosures
IEEE 472:
(ANSI C37.90A): Ringing wave immunity
EN55022(CISPR11): Conducted and radiated emissions (Exceeds EN55011 & Class B: MILSTD 461
Class 3)
EN61000-4-2:
(Level 4): ESD immunity test
EN61000-4-3:
(ENV50140): Radiated RF, electromagnetic field immunity test
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Date: December 11, 2008
2.
EN61000-4-4:
Electrical fast transient/burst immunity test
EN61000-4-5:
IEEE C62.41: Surge immunity test (1.2 x 50μs, 5 & 8 kV)
EN61000-4-6:
(ENV50141): Conducted immunity test
0EN61000-4-11:
Voltage dips and interruption immunity
Listed below are other frequently requested optional features that are available for ZBTSD transfer switches:
B
Battery Chargers
F
Fan Contact: Closed when engine runs (S.P.N.O.)
H
Time Delay - Engine Start: Non-adjustable delay on starting engine after normal failure. Factory
set at 3 seconds; includes Accessory E
HT
Heater and Thermostat
P2
Extended Time Delay - Engine Start: Adjustable 0.5 to 300 seconds
Q7
Inhibit Transfer to Normal: Input circuit to inhibit transfer to normal;
120 VAC or 24 VDC
R15D Load Shed Control (ZTSD): Input to remote circuit for load shed from emergency to center-off
position; 120 VAC or 24 VDC
S
6
Selector and Disconnect Switches:
S1
Three-position selector switch; Stop/Test/Automatic
S2
Disconnect switch in series with Accessory E to disconnect engine starting circuit
S3
Source selector switch circuit to select either source as primary
S5
Combination auto/manual retransfer selector switch
S12
Automatic/manual operation for ATS
S14
Retransfer to normal/test/auto (key operated)
Test Switch: A pushbutton (momentary) test switch is standard on all ZTS Automatic Transfer
Switches; MX 250 microprocessor switches are standard with load/no load and fast test (with
load) modes and are pass code protected; other selector switches, available at additional cost,
include:
6A
Maintained Auto - Maintained Test
6B
Maintained Auto - Momentary Test (key operated)
6C
Maintained Auto - Maintained Test (key operated)
Many additional accessories are available to meet your installation requirements. Consult your GE Zenith
representative with your project needs.
Publication # GS-1105
ZBTSD Series ATS - Page 8
Date: December 11, 2008