Spec Sheet:
Zenith ZTG Transfer switch
General Purpose Commercial & Industrial
Description:
GE Zenith’s ZTG Series Automatic Transfer Switches are
designed for General Purpose Commercial & Industrial nonlife safety applications requiring Standard or Delayed
transition for motor, transformer or UPS switching. They offer
the dependability and ease of operation found in a power
contactor switch.
Ratings: 40A / 80A /100A / 150A /200A / 225A / 260A
/400A /600A /800A / 1000A /1200A /1600A /2000A /2600A
/3000A
Versions: 3P/3P & 4P/4P pole.
Fully Approved:
Enclosure if required can be
• UL 1008, CSA and IEC 60947-6-1 listed to 480 VAC 50/60Hz
supplied to suit application
• Ringing wave immunity per IEEE 472 (ANSI C37.90A)
• Conducted and Radiated Emissions per EN55022 Class B (CISPR 22) (Exceeds EN55011 & MILSTD 461 Class 3)
• ESD immunity test per EN61000-4-2 Class B (Level 4)
• Radiated RF, electromagnetic field immunity test per EN61000-4-3 (ENV50140) 10v/m
• Electrical fast transient/burst immunity test per EN61000-4-4
• Surge immunity test per EN61000-4-5 IEEE C62.41 (1.2 X 50µs, 0.5 & 4 kV)
• Conducted immunity test per EN61000-4-6 (ENV50141)
• Voltage dips and interruption immunity EN61000-4-11
Features:
Double throw, mechanically interlocked contactor mechanism.
Late Break, Early Make Neutral.
Electrically operated, mechanically held.
Designed for emergency and standby applications
Available in standard (ZTG or Delayed transition (ZTGD) models
ZTG switches are equipped with GE Zenith’s next-generation MX150 microprocessor panel, which controls the
operation and displays the status of the transfer switch’s position, timers and available sources.
As an embedded digital controller, the MX150 offers high reliability and ease of unattended operation across a range
of applications.
Types of Transition
Required to be specified at time of order:
Normal
Supply
Emergency
Supply
Load
Open Transition
Break before Make
Ordering Information
Delayed Transition
(With Center OFF Position)
NOTE: “OFF” Position indicates
Neither Source connected
Open type - 240/415V 50Hz (240Vac control voltage)
Open Transition (unenclosed):
200A – 4Pole/4Pole - ZTGAO20F93A3A4
260A - 4Pole/4Pole - ZTGAO26F93A3A4
NOTE: This PRODUCT is Made in the USA. All Hardware
threads and bolts used is not metric.
400A - 4Pole/4Pole - ZTGAO40F93A3A4
Other sizes: contact IPD
Options included:
MSTDG refer options table (Page.4)
Auxiliary contacts (A3/A4- 1 each n/o) A4 closed in normal and A3 closed in emergency positions.
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Fault Rating Icm / Icw
Icm/Icw. (protected by upstream GE circuit breaker) Up 480V a.c.
ATS Rating:
Fault rating: Upstream Coordinated Breaker
40-225A
30kA
Max GE MCCB 400A
260A -400A
50kA
Max GE MCCB 600A
600A
65kA
Max GE MCCB 800A
800A
65kA
Max GE MCCB 1200A
1000A- 1200A
85kA
Max GE MCCB 1200A
1600A-2000A
100kA
Max GE Breaker same rating as ATS
Reference Document GE TB-1102K Page 5
Testing Standards
-3-
Logic Controller
The MX150 features include:
• Timer and voltage/frequency settings adjustable without
disconnection from the power section
• Built-in diagnostics with an LCD display for immediate
troubleshooting
• Event Log of last 16 events.
• In Phase Monitor (see description later in document)
• LED/LCD indicators for ease of viewing and long life
• Nonvolatile memory—clock battery backup not required
for standard switch operation
• Processor and digital circuitry isolated from line voltage
• Inputs optoisolated for high electrical immunity to
transients and noise
• Communications Modbus network interface (RS232)
The MX150 comes in two standard configurations:(refer
table below)
MSTDG –(Stocked)
MEXEG – Indent
Both of these configurations also have additional option
which can be added to special order.
Settings
-4-
MX150 - LCD & Keypad
The SET (setting) menu is primarily used to show or change,
time and voltage settings.
The CFG menu is primarily used to turn an option on or off.
When scrolling through these menus, no changes can be made
without entry of the access code.
The factory set six-digit access code is located on a white label
on the back of the unit.
-5-
MX150 – Components (Rear view)
Engine Start Relay
In-Phase Monitor
ZTG ATS senses when the sources are as far out as 2 Hz or as close
as .01Hz in frequency differential of each other and transfers the load
to and from either source in-phase.
The monitor tracks the frequency of both the Utility and Generator
sources allowing a smooth, synchronous transfer of the load, which is
especially beneficial where conveyors, pumps and other motor loads
are involved.
ZTG indicates it is waiting for the sources to synchronize by holding
the Timer/In-Phase LED on. When synchronized, the ATS will transfer
the Load (within 20° of each other, if sources are within 2Hz
differential), and the Timer/In-Phase LED will turn off.
If the sources fail to synchronize, after 1 minute, the controller will
blink the Timer/In-Phase LED once, alerting the operator that the InPhase monitor function can be bypassed by pressing the CANCEL key,
causing an immediate transfer (see Cancel Key function).
If the CANCEL key is not pressed, the ZTG will continue to wait for an
in- Phase condition to occur.
Controls Power Supply (CPS).
(Drops Voltage from Line Voltage
to Controller input)
Controls Power Supply (CPS).
(Drops Voltage from Line Voltage
to Controller input)
In a typical ATS application, one source is on the utility and one source is a backup system such as a gas or diesel generator. Because
sources have a slight frequency difference, sources come in and out of phase.
If ZTG In-Phase Monitor is on, The ZTG ATS Controller monitors both sources and transfers the Load at the ideal time to minimize
back-EMF conditions.
In the case of both sources coming from the same source, or, one configured as WYE and the other as DELTA, the frequency
difference is fixed at the same frequency or fixed but 30 degrees out of phase. In those cases, In-Phase Monitor can be turned off.
In-Phase Monitor is turned on as default from the factory. To turn In-Phase Monitor OFF or ON, take the following steps:
Turn In-Phase Monitor OFF:
1. Remove all power, (both S1 and S2) from the controller. Wait at least 20 seconds.
2. From the keypad, hold both the BYPASS and CANCEL keys down while energizing either source. If In-Phase Monitor was on, the
Timer / In-phase LED will flash once for 1 second, then go out. The In-Phase Monitor is now off.
Turn In-Phase Monitor ON:
1. Remove all power, (both S1 and S2) from the controller. Wait at least 20 seconds.
2. From the keypad, hold both the BYPASS and CANCEL keys down while energizing either source. If In-Phase Monitor was off, the
Timer/In-Phase LED will light and remain lit
until the keys are released. The In-Phase Monitor is now on.
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Operating Sequence
Standard Transition
Source 1 Power Failure:
When voltage or frequency has fallen below the preset "Fail" values;
-The controller initiates the Time Delay Engine Start Timer "P".
- Engine start Signal is sent to Source 2.
When Source 2 voltage and frequency reach the preset "Restore" Values,
- The time delay to Source 2 Timer (W) begins (to ensure voltage and frequency stabilization before transfer).
- A manual pushbutton BYPASS is provided to bypass the "W" time delay if desired.
- The load is now transferred to Source 2 line.
-The transfer switch is mechanically locked. SN limit switch awaits the next operation to Source 1.
Restoration of Source 1 Power:
When Source 1 power reach the preset "Restore" values;
- The delay to Source 1 Timer (T) begins (to ensure voltage and frequency stabilization before retransfer).
- A manual pushbutton BYPASS is provided to bypass the "T" time delay if desired.
- The load is now transferred to Source 1.
- The transfer switch is mechanically locked. SE limit switch awaits the next operation to Source 2.
- The S2 Stop Delay Timer (Delay to Engine Stop "U") begins (to allow Source 2 Engine to run unloaded).
- A manual pushbutton BYPASS is provided to bypass the "U" time delay if desired.
- Upon completion of the (U) timing cycle, the controller sends an Engine stop signal.
-7-
Operating Sequence
Delayed Transition
Source 1 Power Failure:
When Source 1 voltage or frequency has fallen below the preset "Fail" values;
- The controller initiates the Time Delay Engine Start Timer "P"
-
Engine start Signal is sent to Source 2.
When Source 2 voltage and frequency reach the preset "Restore" values,
-
The delay to open Source 1 timer (W) begins its timing cycle (to ensure voltage and frequency stabilization
before re-transfer).
-
A manual pushbutton BYPASS is provided to bypass the "W" time delay if desired.
-
The load is transferred to the Open position.
-
The time delay to Source 2 timer (DW) begins its timing cycle.
-
The load is now transferred to Source 2 line.
-
The transfer switch is mechanically locked. SN limit switch awaits the next operation to Source 1.
Restoration of Source 1 Power:
When Source 1 power reaches the preset "Restore" values;
- The delay to open Source 2 Timer (T) begins (to ensure voltage and frequency stabilization before retransfer).
- A manual pushbutton BYPASS is provided to bypass the "T" time delay if desired.
- The load is now transferred to the Open position.
- The time delay to Source 1 timer (DT) begins its timing cycle.
- The load is now transferred to Source 1.
- The transfer switch is mechanically locked. SE limit switch awaits the next operation to Source 2.
- The S2 Stop Delay Timer (Delay to Engine Stop "U") begins (to allow Source 2 Engine to run unloaded).
- A manual pushbutton BYPASS is provided to bypass the "U" time delay if desired.
- Upon completion of the (U) timing cycle, the controller sends an Engine stop signal.
-8-
Connections
Optional Auxiliary Contacts :
A4 – Utility
A3 – Generator
Load Terminals
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Dimensions – 600A
- 10 -
Dimensions – 800A
- 11 -
Dimensions – 1600A -2000A
- 12 -
Schematic 40A – 3000A
- 13 -
- 14 -
Typical applications:
1) I Utility & 1 Gen set
Utility Source
Circuit Breaker to provide
standard function of protecting
loads from over-current
G
Generator Set
ATS provide standard function
of transfer switch
Essential Loads
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