Power Transfer Switch, ATS | ASCO 7000 Series | Emerson


The ASCO 7000 Series Power Transfer Switch is available in the conventional, two-position transfer configuration, and closed or delayed transition modes of operation. Additionally, switched or overlapping neutral options provide for reliable operation of ground fault protection systems and reduction of voltage transients from unbalanced load switching. Click here to read an article describing the sizing considerations when using a closed transition mode of operation.




  • Conventional two-position transfer configuration, plus closed and delayed transition modes of operation. All configurations available with either automatic or non-automatic control.
  • Available in bypass-isolation configuration. The bypass and isolation features allow power transfer switches to be inspected, tested, and maintained without any interruption of power to the load. Click here to view the instructions on how to use the bypass and isolation handles. Click here to view the transfer switch draw out features.
  • UL listed to 1008 Transfer Switch Equipment & CSA certified to CSA 22.2 No. 178-1978 Automatic Transfer Switches.
  • Independently qualified and certified listed to IEC 60947-6-1, CE marked (optional). (Limited to certain accessories.)
  • Rated up to 600 VAC, 30 through 4000 amperes.
  • High withstand and close-on ratings including 30 cycle withstand current rating for optimum flexibility in circuit breaker coordination (600-4000 amperes).
  • Solid, switched, or overlapping neutral conductor options.
  • Front replaceable main and arcing contacts (800-4000 amperes).
  • Programmable microprocessor controller with keypad and LCD display.
  • Centrally located terminal block for customer control connections (260-4000 amperes).
  • 16mm, industrial grade control switches and indicating lights.
  • Switch position indicators and true source acceptability lights.
  • Standard ground conductor connections.
  • Four auxiliary contacts, two contacts closed when switch is in normal position and two contacts closed when switch is in emergency position.
  • Local/remote serial communications capability for interfacing with ASCO PowerQuest® communication products.


  • Reliable and field-proven solenoid operating mechanism ensures maximum performance
  • High withstand and close-on ratings including 30 cycle withstand current rating provides optimum flexibility in circuit breaker coordination (600-4000 amperes).
  • Local or Remote serial communication options provide user flexibility.
  • Protected by a comprehensive warranty. Click here for details.
Time Delays
2C An extended time delay on engine starting. Adjustable from 0 to 60 min in 1 second steps. Factory set at 5 minutes.
1G Similar to accessory 2C except using 24 volt DC external input signal. 7000 Series controller remains active when both power sources are de-energized.
Manual Controls for Automatic Transfer Switches
6C Reset switch for manual retransfer to normal with automatic retransfer in the event of emergency source failure.
6D Selector switch for automatic/manual retransfer to normal. Automatic bypass if emergency fails.
Engine Generator Controls and Accessories
12 Three position engine control selector switch.
Positions: 1 - Stop 2 - Automatic 3 - Engine Test
Note: The addition of accessory 12 requires the product to be labeled "Non-Automatic Transfer Switch" as defined in UL1008.
Engine controls containing engine stop positions should be located at the engine generator. (Consult ASCO for application assistance).
14A/14B Additional auxiliary contact sets to indicate switch position. Two sets are standard. Specify total number of sets if more are required.
18B Two-pole, double-throw contacts operate when emergency source voltage is present at transfer switch terminals.
18G Two-pole, double-throw contacts operate when normal source voltage is present at transfer switch terminals.
99 Push-to-Test feature on all pilot light indicators.
Customer Control Circuits
30A Load-shedding circuit initiated by opening of a customer-supplied contact.
30B Load-shedding circuit initiated by removal of customer-supplied control voltage. (Specify voltage).
31Z Selective load disconnect control contacts (two provided) which operate with time delay prior to and/or after load transfer and retransfer.
43R Terminal block for all customer control connections on 30-150 amp only (standard on all other sizes).
Neutral Conductor Options
Solid neutral, with fully-rated terminals. (AL-CU) UL Listed.
Conventional neutral switching pole.
Overlapping neutral transfer contacts. Allows for proper ground-fault sensing and avoids generator voltage transients during transfer.
Notes: Specify neutral option in catalog number, see page 16 for instructions.
Extension Harness
37B Six foot (6') extension harness to increase distance between transfer switch and control panel on open-type units.
Analog Load Metering Options
23B Three phase ammeter with selector switch (with current transformers and shorting blocks).
24B Three phase voltmeter with selector switch.
Notes: Refer to ASCO 7000 Series Data Monitor which provides voltage, frequency and power monitoring.
Serial Communications
72A Serial communication module for remote communications to ASCO Power Quest products.
Surge Protection - ASCO Pulsar 450 rated 40KA
73AC1 Normal source protection. (3Ø, 4wire WYE)
73AC2 Emergency source protection. (3Ø, 4wire WYE)
73AC3 Load side protection. (3Ø, 4wire WYE)
Notes: Other distribution voltages available (Contact ASCO).
Special Applications
111A Generator-to-Generator for Standby Applications
111B Generator-to-Generator for Prime Power Applications
Bypass Isolation Switch Options
14A1 Auxiliary contact to close in Bypass to Normal position.
14B1 Auxiliary contact to close in Bypass to Emergency position.
14T Auxiliary contact to close when transfer switch is in Automatic position.
14U Auxiliary contact to close when transfer switch is in Isolate position.
14V Auxiliary; contact to close when transfer switch is in Open position.
14W Auxiliary; contact to close when transfer switch is in Test position.
ATS Bypass Isolation Drawout Features (1000-2000 amperes)
82B Transfer switch lifting yoke to facilitate the removal of the transfer switch from the drawout carriage.
82C Automatic shutters to provide isolation of bus stabs.
Notes: An externally operable quick-make, quick-break (QMQB), manual handle is available on some 7000 Series product configurations. (Consult ASCO for guidance).
Seismic Qualification for Automatic Transfer Switches
125 Factory qualified seismic rating to IBC2003 code. Contact Customer Care for information
Misson-Critical Care
Our comprehensive service portfolio extends beyond routine maintenance to include solution upgrades and technology training that ensure you get the most from your emergency power systems.

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