ASCO Logo Series 300 SE

185 Manual or Automatic, Door Closed
Series 300 SE, Industrial Manual Transfer Switches, Enclosed Only with Open and Delayed Transitions
ASTR-300 SE (341)
70 to 3,000 Amp, Indoor, Outdoor, Explosion Proof, Stainless and Accessories 100, 200, 230 & 400 Amp, Indoor & Outdoor, Light Duty,    >>>>Order online or call PowerPixie @ 707 542-2224 to take your order. GSA Pricing Available.
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  • Detailed Description
      ASCO Series 300 SE Transfer Switch Group - Manual Transfer Switches - Enclosed Only, Not available open.
    As the world leader in emergency and standby power transfer solutions, ASCO keeps your power on. ASCO, Manual Transfer Switches and Power Systems safeguard data and telecommunications networks, industrial processes and critical installations from health care facilities to financial transaction centers.

    Over the past 70 years, ASCO has pioneered every major product innovation in power transfer technology. And ASCO is committed to providing a full range of quality-driven products, backed by 24-hour nationwide service support.

    ASCO Series 300 3AUS (Automatic) and 3NUS (Manual) - ASCO Series automatic and manual transfer switches are suitable for standby power system applications. These switches are identical to the Series 300 they do not have an automatic operation but are electrically operated. Manual switches cannot be upgraded to automatic later. GeneratorJoe recommends that customers purchase automatic switches and operate them in manual mode.  The prices are the same for both automatic and manual.  Some options available for the Series 300 are not available for Series 300 SE.

    Standard switches in sizes 70 through 3000 Amps, in a compact design with 2, 3, & 4 pole configurations. Available 120 to 600 VAC. UL 1008 listed to 480 VAC for total system loads. True double-throw, inherently interlocked construction to absolutely prohibit connecting both sources together. Mechanically held, electrically operated utilizing a reliable, field-proven single solenoid operator. Contacts easily accessible for easy inspection and preventive maintenance. Meets National Electric Code requirements (U.S.). Rated for emergency and standby applications.

    • Standard models in stock dropped shipped to your location.
    • Available in Standard open transition sizes 30 through 3000 Amps. Nema Type 1, 3R, 4 and 12 from 30 to 1600 Amps, (some exceptions).
    • Available In "Fully Automatic" versions. See ASCO Transfer Switch Group - Automatic Transfer Switches - Enclosed & Open - Series 300
    • Available in SE (Service Entrance Type) with integral main breaker.
    • SE Series available in sizes 70 through 3000 Amps in enclosures in "Secure" Type NEMA 1, 3RS, 4S and 12S.
    • SE Series 3R enclosures include 44A strip heater, 120 volt power source required. (built-in).
    • Doors are hinged, heavy duty type with a secured latching mechanism.
    • Qualified and listed to CSA C22.2 No. 178 and UL 1008 manual transfer equipment standards.
    • For technical data, dimensions, features, warranty and other information. See Additional Information below.

    ASCO Manual Transfer Switch, "Standard" Features - Enclosed - Series 300 SE

    Test switch Source available lights Auto engine exerciser with load/no load switch
    ATS switch position indicating lights Load disconnect contacts, with TD which operate before/after transfer ATS position indicating contacts, Normal, Emergency
    In-phase monitor for motor load transfer Standard Manual & Service Entrance Type  

    ASCO Accessories For Series 386 Transfer Switches

    Number Accessory Name
    44A Strip heater w/ thermostat, external 120-volt power source required. (included in 3R enclosures).
    2EXW386 Two Year Extended Warranty (parts & labor)
    3EXW386 Three Year Extended Warranty (parts & labor)
    4EXW386 Four Year Extended Warranty (parts & labor)
    5EXW3086 Five Year Extended Warranty (parts & labor)

  • This product does not have designated product packages.

    Please see the Priced Options tab and select the options you want supplied with the product. Prices will update automatically when you select or remove an option.

    Purchase option only
    Transfer Switch Voltages @ 60 Hertz Details
    Transfer Switch Voltages @ 50 Hertz Details
    Switch Selector - AUTOMATIC or MANUAL Details
    Extended Warranties Details
    ASCO Auto & Manual Transfer Sw, Svc Entrance, 300SE, 3AUS / 3NUS Details
    ASCO Auto & Manual, 300 Series, Service Entrance Enclosures Details
    ASCO Auto & Manual Sw Svc Ent, Delayed Trans, 300, 3ADUS / 3NDUS Details
    ASCO 300SE Series Service Entrance Enclosures Details
    Heaters Details
    Auxiliary Contacts Details
    Wiring Components Details
    Communications Options Details
    Special Options Details
  • Standard Features
    Series 300 SE, Industrial Manual Transfer Switches, Enclosed Only with Open and Delayed Transitions
    Close differential 3 phase under-voltage sensing of Source1 (normal) - factory standard setting 90% pickup, 80% dropout (adjustable); under-frequency sensing of Source 1 factory setting 95% pickup (adjustable).
    Contact transfer speed less than 100 milliseconds
    eTemperature rise test per UL 1008 conducted after overload and endurance tests in unventilated enclosure-exceeds UL requirements
    High close-in and withstand capability
    NEMA Type 1 enclosure is standard. Also available in NEMA 3R, 4, 4X & 12.
    Voltage and frequency sensing of the Source 2 (emergency) - factory standard setting 90% pickup voltage, 95% pickup frequency (adjustable).
    Indicating LEDs for source availability and switch position.
    Pushbuttons for test, exerciser set, timer bypass and program cancel.
    Special status annunciation of in-phase transfer and timer operation.
    Selectable 7, 14, 21 or 28 day (factory set 28 dsays) generator (source2) with or without load exerciser timer.
    Diagnostic LED indications in logical one-line configuration.
    Auxiliary contacts (1 each) cclosed in Source 1 (normal) and Source 2 (emergency positions.
    Close differential under-voltage sensing of the normal source.
    Voltage and frequency sensing of the emergency source.
    Test switch (fast test/load/no load) to simulate normal source failure - automatically bypassed should the emergency source fail .
    Double throw, interlocked operation .
    Electrically operated, mechanically held by a simple, over-center mechanism.
    Segmented silver tungsten alloy contacts with separate arcing contacts on 600 amps and above.
    Arc quenching grids, enclosed arc chambers and wide contact air gap for superior source-to-source isolation on all units.
    Control circuit disconnect plug and drive inhibit switch for safe maintenance.
    Components accessible for inspection and maintenance without removal of the switch or the power conductors.
    Mechanical indicator and contact chamber cover designed for inspection, safety and position designation.
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General Notes: Proudly made in the USA by Americans!