The Series 300 is listed to UL 1008 standard for Transfer Switch Equipment and CSA standard C22.2 for automatic transfer switches.
Meets NFPA 110 for Emergency and Standby Power Systems and the National Electrical Code (NEC) Articles 700, 701 and 702.
30 through 3000 amps in a compact design.
Available to 600 VAC, single or three phase.
True double-throw operation: The single solenoid design is inherently interlocked and prevents contacts from stopping between sources or from being in contact with both sources at the same time.
There’s no danger of the Series 300 ATS transferring loads to a dead source because the unique ASCO single-solenoid operator derives power to operate from the source to which the load is being transferred.
Easy-to-read flush-mounted control and display panel provides LED indicators for switch position and source availability. It also includes test and time-delay bypass switches as standard features.
Standard engine exerciser for weekly automatic testing of engine generator set with or without load.
Adjustable time-delay feature prevents switch from being activated due to momentary utility power outages and generator dips.
Supplied with solid neutral termination. Optional switched neutral pole available.
Accessory kits available.
Available for immediate delivery.
Now available for service entrance applications. Contact ASCO for assistance.
Designed to Fit Anywhere
The ASCO Series 300 product line represents the most compact design of automatic power transfer switches in the industry. With space in electrical closets being at a premium, the use of wall or floor-mounted ASCO Power Transfer Switches assures designers optimum utilization of space.
All transfer switches through 2000 amps are designed to be completely front accessible permiting the enclosures to be installed flush to the wall and still allows installation of all power cabling and connections from the front of the switch. Cable entrance plates are also standard on the 1600 and 2000 amp units to install optional side-mounted pull boxes for additional cable bending space. The ASCO Microprocessor Controller is used with all sizes of Power Transfer Switches. It represents the most reliable microprocessor controller in the industry and includes, as standard, all of the voltage, frequency, control, timing and connectivity functions required for most emergency and standby power applications.
Voltage & Frequency Sensing
Adjustable three-phase, close-differential voltage sensing on normal source.
Normal source pickup voltage is adjustable to 95% of nominal; drop-out is adjustable from 70% to 90% of nominal.
Frequency sensing on emergency source. Pickup at 95% and dropout at 85% of nominal.
Time Delays
Adjustable time delay to override momentary normal source outages to delay all transfer switch and engine starting signals.
Transfer to emergency time delay—Adjustable from 0 to 5 minutes for controlled timing of load transfer to emergency.
Retransfer to normal time delay—Adjustable to 30 minutes.
Five-minute unloaded running time delay for emergency engine generator cool down.
Four-second time delay to ignore momentary voltage and frequency transients during initial genset loading.
Standard Selectable Features
Inphase monitor to transfer motor loads, without any intentional off time, to prevent inrush currents from exceeding normal starting levels.
Engine exerciser to automatically test backup generator each week—Includes control switch for testing with or without load.
Selective load disconnect, double-throw contact to operate at an adjustable 0 to 20 second adjustable time delay prior to transfer and reset 0 to 20 seconds after transfer.
60 Hz or 50 Hz selectable switch.
Three-phase/single-phase selectable switch.
Remote Control Features
Terminal provisions for connecting:
Remote test switch.
Remote contact for test or for peak shaving applications. Circuit will be automatically bypassed if emergency source fails.
Inhibit transfer to emergency.
Remote time-delay bypass switch.
Control and Display Panel
Easy-to-read flush-mounted control and display panel provides LED indicators for switch position and source availability. It also includes test and time-delay bypass switches.
Performance Features
600 volt spacing per UL and CSA standards.
Interfacing relays are industrial grade, plug-in type with dust covers.
Meets or exceeds the requirements for Electromagnetic Compatibility (EMC).
ANSI C37.90A/IEEE472 Voltage Surge Test
NEMA ICS-109.21 Impulse Withstand Test
Digital circuitry isolated from line voltages
IEC 801-2 Electrostatic discharge (ESD) immunity
ENV50140 and IEC 803-1: Radiated electromagnetic field immunity
IEC 801-4 Electrical fast transient (EFT) immunity
ENV50142 Surge transient immunity
ENV50141: Conducted radio-frequency field immunity
EN55011: Group 1, Class A conducted and radiated emissions
Optically isolated RS-485 Serial Port
EN61000- 4-11 voltage dips and interruptions immunity
Amps - 230
Phase - Single or Three
Poles - 2 for single phase or 3 for three phase
Dimensions/Weight -
Non-Service Entrance Rated
W 18 x H 48 x D 13 NEMA 1 / 100 to 120 Lbs
W 18 x H 50.5 x D 14.4 NEMA 3R / 132 to 148Lbs
Service Entrance Rated
W 36.5 x H 48.5 x D 13.25 NEMA 1 / 400 to 408 Lbs
W 36 x H 48 x D 16 / NEMA 3R / 180 to 196 Lbs
External Power Connections (Lug Configuration)
Amp Size Wire Size Range
230 (1) #14 to 4/0 AWG per pole
Note: All Series 300 switches are furnished with a solid neutral plate (unless switched neutral configuration is specified) and terminal lugs. Warranty - 18 Months Limited Warranty - for details see www.ascopower.com
