Power Transfer Switch, ATS | ASCO 4000 Series | Emerson

ASCO Power Transfer Switches are the standard of the industry. High speed transfer of loads between alternate sources of power, regardless of ampacity size, is achieved by a reliable, field proven solenoid operating mechanism.

When combined with a programmable microprocessor controller with keypad and LCD display, they offer the most advanced method of transferring all types of loads, such as motors, electronic drives, UPSs and microprocessor based systems.

4000 Series Power Transfer Switches are available open or enclosed, in ampacity sizes from 30 through 4000 amperes with a limited selection of optional accessories.
Product Features

  • Conventional two-position transfer configuration, plus closed and delayed transition modes of operation. All configurations available with either automatic or non-automatic control.
  • UL listed to 1008 Transfer Switch Equipment & CSA certified to CSA 22.2 No.178-1978 Automatic Transfer Switches.
  • Qualified to IEC 60947-6-1, CE marked (optional). (Limited to certain accessories.)
  • Rated up to 600 VAC, 30 through 4000 amperes.
  • Front replaceable main and arcing contacts (800-4000 amperes).
  • Programmable microprocessor controller with keypad and LCD display.
  • Industrial grade user interface with integrated controls and indicating lights.
  • Convenient one tine diagram with switch position and source acceptability LED indicators.
  • 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 communications capability for interfacing with ASCO PowerQuest® or SiteWeb® communication products.
*Only two contacts standard on 150-400A 4ACTS and 4NCTS

  • Reliable and field proven solenoid operating mechanism.
  • High withstand and close-on ratings including short time withstand current rating for optimum flexibility in circuit breaker coordination (800-4000 amperes).
  • Solid, switched neutral configurations available.
Time Delays
2C Provides an extended time delay on engine starting. The standard feature one time delay is adjustable from zero to six seconds. Accessory 2C allows this time delay to be adjustable from zero to sixty minutes in one second intervals factory set at five minutes.
1G Similar to accessory 2C except using an external 24 volt DC power input. Available only as a feature of accessory 18Z.
14A/14B Additional auxiliary contact sets to indicate switch position. Two sets are standard. Maximum number of two additional sets. (Varies by configuration)
Neutral Conductor Options
â–ª Solid neutral, with fully-rated terminals. (AL-CU) UL Listed.
â–ª Conventional neutral switching pole.
Note: Specify neutral option in catalog number, see ordering information page for instructions.
Communications Options
72A Serial communication module for remote communications to ASCO PowerQuest® or SiteWeb® products. Also allows 4000 Series Transfer Switches to communicate via Modbus/RTU.
72E Ethernet connectivity module for remote communications to ASCO PowerQuest® or SiteWeb® products. Contains embedded web pages for the remote monitoring of ASCO products, as well as some 3rd party devices. Also, provides Serial-to-Ethernet link with ability to communicate using Modbus/TCP.
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).
Add-on Boards
18Z Includes one Form C contact (Rated 2A @ 30VDC or.5A@ 125VAC) for each of the following:

  • Normal Source Acceptability.
  • Emergency Source Acceptability.
  • Selective Load Disconnect. - Pre and post transfer signal time delay for selective load disconnect with a programmable bypass on source failures - adjustable 0 to 5 minutes.
  • Fourth contact can be set to mimic the acceptability contacts or annunciate any combination of the acceptability contacts and/or any switch alarm conditions available:

    • Extended Parallel Time (Closed transition),
    • Failure to Synchronize (Closed transition),
    • Transfer Switch Locked Out (Closed transition),
    • Load Disconnected (Delayed transition).
  • Accessory 18Z includes an extension of the engine start time delay (feature) to 60 seconds if an external 24VDC supply is connected to a 4000 series controller. This external power source will also allow the LCD display to be active when both normal and emergency sources are unavailable.
    • 18Z2 Includes two 18Z accessory boards. (Maximum of two 18Z accessory boards allowed.)

      4000 Series Accessory 18Z mounting on User Interface

      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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