Critical Power

from GE

Zenith ZBTS/
ZBTSD/ZBTSCT
Transfer/Bypass-Isolation
Transfer Switches

Introduction Design and Advantages

GE’s Zenith ZBTS Series Bypass Isolation Construction Features • Load is not interrupted
Transfer Switch consists of two major
modules – the automatic transfer and the
• Automatic transfer switch is during bypass operation
located on a draw out mechanism
bypassisolation switches. The automatic
transfer switch module is GE’s proven
to facilitate maintenance • High close-in and
Zenith ZTS Series, built in ZTS, ZTSD or • Emergency power systems withstand capability
ZTSCT configuration and constructed can be electrically tested
for rugged, reliable operation. The same without disturbing the load • Temperature rise test
components – heavy-duty silver alloy • Power cables do not have to per UL 1008 conducted
contacts, rugged drive mechanism and be disconnected to remove after overload and
silver plated bus bar inter-connections the transfer switch
are used throughout the ZBTS Series.
endurance tests exceeds
• Bypass to any available UL requirements
source with the automatic
transfer switch removed • Available in ZBTS (utility-
Features and Benefits • Engine start circuit maintained during generator), ZBTSU
GE’s design requires no additional bypass operation; normal power
load break contacts which cause load
(utility-utility), ZBTSG
failure causes engine start contact
interruption during bypass-isolation closure even with the ATS removed (generator-generator)
functions. The bypass-isolation switch
• Diagnostic lights and detailed
and ZBTSM (manual)
contacts are out of the system current
instructions for simple step- configurations; models
path except during actual bypass
operation. Therefore, they are not
by-step operation include standard, delayed
constantly exposed to the destructive • Mechanical and electrical interlocks and closed transition
effects of potential fault currents. The ensure proper sequence of operation
Source 1 (normal), Source 2 (emergency) • Bypass switch contacts are closed only
and load are connected between during the bypass-isolation operation
the automatic transfer switch and
• Silverplated copper bus
the bypass-isolation switch through
interconnection of the transfer
solidly braced isolating contacts that
and bypass switches on all sizes
are open when the automatic transfer
switch is isolated. All current carrying
components provide high withstand
current ratings in excess of those
specified in UL 1008 standards.
Description and Operation
The bypass section is a ZTS switch provided with a quick make/quick break manual load transfer handle and GE’s control/interlock
system consisting of both mechanical and electrical interlocks. The bypass switch is equipped with normal failure sensing and
a time delay to start the engine automatically if the ATS has been removed for service. The modules are mounted in a compact
enclosure and completely interconnected requiring only Source 1 (normal), Source 2 (emergency) and load cable connections.
Once installed, no cables need to be removed to isolate the transfer switch module for maintenance or inspection. The automatic
transfer switch may be withdrawn for testing or maintenance without disturbing the load. The transfer switch module has
three positions:
1. Automatic/Connected: The transfer switch is carrying the load, and the bypass switch is in the open position. This is the normal
operating position.
2. Test: The bypass switch is closed and feeding the load. The transfer switch has control power and may be operated for test
purposes via the test switch on the enclosure door. The load is not affected during testing.
3. Isolate: The transfer switch is withdrawn from all power and ready for maintenance. The load is served by the bypass switch.

The Automatic Transfer Switch is installed on a draw-out mechanism, with electrical and mechanical interlocks for secure
removal after load bypass. The ATS control/logic panel is mounted on the enclosure door and connected by a wire harness and
multi-pin disconnect plugs. The transfer switch and/or the control panel may be tested, isolated and removed for maintenance
without load interruption.

The bypass-isolation switch module is the same basic design as the automatic transfer switch module and thus has the same
electrical ratings. Manually operated, it features high speed, quick make/quick break contact action. The bypass-isolation switch
has three basic positions:
1. Automatic: Source 1 (Normal) bypass contacts open, Source 2 (emergency) bypass contacts open.
2. Bypass Normal: Source 1 (Normal) bypass contacts closed, Source 2 (emergency) bypass contacts open.
3. Bypass Emergency: Source 1 (Normal) bypass contacts open, Source 2 (emergency) bypass contacts closed.

Interlocks and Indicators

Every ZBTS Series Bypass-Isolation Transfer Switch is supplied with all necessary electrical and mechanical interlocks to prevent
improper sequence of operation as well as the necessary interlocking circuit for engine starting integrity. Each ZBTS Series
Switch is furnished with a detailed, step-by-step operating instruction plate, as well as the following function diagnostic lights:
• Source 1 (Normal) Available
• Source 2 (Emergency) Available
• Bypass Switch in Source 1 (Normal) Position
• Bypass Switch in Source 2 (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 Source 1 (Normal) Position
• Automatic Transfer Switch in Source 2 (Emergency) Position

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Electrical Ratings
• Ratings 100 to 4000 amperes
• 2, 3 or 4 Poles
• Open type, NEMA 1, 3R, 4, 4X and 12
• Available with Zenith ZTS, ZTSD and ZTSCT Series Automatic Transfer Switch
• Bypass and transfer switch have identical ratings
• Suitable for emergency and standby applications on all classes of load, 100% tungsten rated through 400 amps
• UL 1008 listed at 480 VAC
• CSA C22.2 No. 178 certified at 600 VAC

UL 1008 Withstand and Closing Ratings

• Please refer to GE Publication TB-1102

Specifications

ZBTS & ZBTSD

AMPERE RATING POLES NEMA 1 ENCLOSED WEIGHT APPLICATION
NOTES
HEIGHT (A) WIDTH (B) DEPTH (C) REFERENCE FIGURE OPEN TYPE NEMA 1

100, 150, 2, 3 83 (211) 30 (76) 28.5 (72.4) A 310 (141) 770 (350) 1–9
225, 260 4 83 (211) 30 (76) 28.5 (72.4) 380 (173) 840 (322)
400
600 3 90 (229) 36 (91) 28.25 (72) B 660 (299) 1220 (533)
4 90 (229) 40 (102) 28.25 (72) 770 (349) 1365 (619)
800, 1000 3 90 (229) 40 (102) 28.25 (72) 765 (347) 1355 (615)
1200 4 90 (229) 46 (117) 28.25 (72) 910 (413) 1570 (712)
1600, 2000 3 80 (202) 40.6 (103) 64.6 (164) C 1978 (897) 4044 (1835) 1 – 7, 10
2600 4 80 (202) 46.1 (117) 64.6 (164) 2275 (1032) 4431 (2010)
3000 3 80 (202) 40.6 (103) 64.6 (164) 2572 (1166) 4456 (2021) 1 – 7,
4 80 (202) 46.1 (117) 64.6 (164) 3049 (1383) 4977 (2258) 10 - 12
4000 3 90 (229) 47.5 (121) 81 (206) D 4310 (1955) 4660 (2113) 1 – 7,
4 90 (229) 54 (137) 81 (206) 5510 (2499) 5860 (2658) 10 – 11

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Specifications (Cont.)

ZBTSCT
AMPERE RATING POLES NEMA 1 ENCLOSED WEIGHT APPLICATION
NOTES
HEIGHT (A) WIDTH (B) DEPTH (C) REFERENCE FIGURE OPEN TYPE NEMA 1
100, 150, 3 90 (229) 36 (91) 28.25 (72) B 730 (331) 1280 (581) 1–8
225, 260 4 90 (229) 40 (102) 28.25 (72) 840 (381) 1385 (628)
400, 600
800, 1000 3 90 (229) 40 (102) 28.25 (72) 835 (379) 1435 (651) 1-9
1200 4 90 (229) 46 (117) 28.25 (72) 980 (444) 1640 (744)
1600, 2000 3 80 (202) 40.6 (103) 64.6 (164) C 1978 (897) 4044 (1835) 1 – 7, 10
2600 4 80 (202) 46.1 (117) 64.6 (164) 2275 (1032) 4431 (2010)
3000 3 80 (202) 40.6 (103) 64.6 (164) 2572 (1166) 4456 (2021) 1 – 7,
4 80 (202) 46.1 (117) 64.6 (164) 3049 (1383) 4977 (2258) 10 - 12
4000 3 90 (229) 47.5 (121) 81 (206) D 4380 (1986) 4730 (2145)
4 90 (229) 54 (137) 81 (206) 5580 (2531) 5930 (2689)

Application Notes
1. Metric dimensions (cm) and weights (Kg) shown in parenthesis adjacent to English measurements in inches and pounds.
2. Includes 1.25” door projection beyond base depth. Allow a minimum of 3” additional depth for projection of handle, light,
switches, pushbuttons, etc.
3. All dimensions and weights are approximate and subject to change without notice.
4. Special enclosures (NEMA 3R, 4, 4X, 12, etc.) dimensions and layout may differ. Consult the GE factory for details.
5. Bypass Model product can not be ordered with inverted style.
6. Special lug arrangements may require different enclosure dimensions. For certified drawings, contact the GE factory.
7. Packing materials must be added to weights shown. Allow 15% additional weight for cartons, skids, crates, etc.
8. Add 4” in height for removable lifting lugs.
9. ZBTS(D) 600-1200A & ZBTSCT 100-1200A standard configuration is top entry. 14” rear adapter bay required for bottom entry.
Consult the GE factory for details.
10. Bypass switch weights for 1600 - 4000 amp units vary up to 10% based on connections variations. Weights shown are for
estimation only.
11. 3000 amp depth dimension shown is standard. Depending on your cable/conduit requirements you may desire a deeper
enclosure. Consult the GE factory for further details.
12. Lug adapters for 3000-4000 amp limits may be staggered length for ease of entrance. Consult the GE factory for details.

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Specifications (Cont.)

Reference Figure
OUTLINE DRAWINGS

Drawing or Diagram

Figure A Figure B Figure C Figure D

ZBTS & ZBTSD: AL-CU UL Listed Solderless Screw-Type Terminals for

External Power Connections
SWITCH SIZE AMPS NORMAL, EMERGENCY & LOAD TERMINALS
CABLES/POLE WIRE RANGES
100-225 1 #6 to 250 MCM
260 #4 to 600 MCM
400
600 2 #2 to 600 MCM
800 / 1000 / 1200 4
1600 / 2000 / 2600 / 3000 / 4000 * *

ZBTSCT: AL-CU UL Listed Solderless Screw-Type Terminals for

External Power Connections
SWITCH SIZE AMPS NORMAL, EMERGENCY & LOAD TERMINALS
CABLES/POLE WIRE RANGES
100-400 1 #4 to 600 MCM
600 2 #2 to 600 MCM
800 / 1000 / 1200 4 #2 to 600 MCM
1600 / 2000 / 2600 / 3000 / 4000 * *

* Line and load terminals are located in rear and arranged for bus bar connection.
* Terminal lugs are available at additional cost. Contact the GE factory for more details.

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Specifications (Cont.)

ZBTSD Model – Delayed Transition Transfer/Bypass-Isolation Switches

The ZTSD Delayed Transition Transfer Switch with a timed center-off position is available in a bypass configuration. The ZBTSD
Model Bypass incorporates the features of both the ZBTS Bypass-Isolation Switch and the ZTSD unit for transfer of large motor
loads, transformers, UPS systems or load shedding to a neutral “Off” position. Reference the ZTSD unit features and operation
discussion for more details.

ZBTSCT Model – Closed Transition Transfer/Bypass-Isolation Switches

The ZTSCT Closed Transition Transfer Switch may be applied with a bypass-isolation switch for the utmost in reliability and
versatility. The ZBTSCT Model provides the ability to withdraw the transfer switch unit for maintenance or inspection. Reference
the ZTSCT unit features and operation discussion for more details.

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 Notes

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On-Site & Emergency Services Training
• 24/7 Emergency Hotline GE offers on-site and classroom training options based on certification curriculum.
Spare Parts Technical training can be tailored to individual customer needs. Training enables
customers and partners to more effectively manage and support the power
• Spare Part Kits
infrastructure. We have built our training program on practical learning objectives
• Product Replacement / Return that are relevant to specific technologies or infrastructure design objectives.
• Equipment Rentals
• Battery & Capacitor Replacements
Contractual Services Service & Support
• Maintenance Service Contracts GE field service and support personnel are trusted advisors to our customers
– always available to answer questions and help with any project, large or
• Remote Monitoring & Diagnostics
small. Our certified professional services team consists of experts in every
• Technical Services aspect of power conversion with the resources and experience to handle
Training large turnkey projects along with custom approaches to complex challenges.
Proven systems engineering and installation best practices are designed
• Training for Operators to safely deliver results that exceed our customers’ expectations.
• Training for Maintenance Staff
• Product Training
• Web-Based Training Warranty
GE is committed to providing quality products and solutions. We have
developed a comprehensive warranty that protects you and provides a
simple way to get your products repaired or replaced as soon as possible.

For full warranty terms and conditions please go to

www.gecriticalpower.com.

GE
Critical Power
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The GE brand, logo, and lumination are trademarks of the General Electric Company. © 2016 General Electric Company.
Plano, TX 75074 Information provided is subject to change without notice. All values are design or typical values when measured under
+1 877 546 3243 laboratory conditions.
www.gecriticalpower.com PB-5068, Rev. 05/2016