ASCO Standard Operational Features, Controls and Status Indicators - Series 300

• In-phase monitor to transfer motor loads without any intentional off time to help prevent motor inrush currents from exceeding normal starting levels.
• Engine exerciser to automatically test engine 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 time delay prior to transfer and reset 0 to 20 seconds after transfer.
• 60 Hz or 50 Hz selector switch.
• Three-phase/single-phase selector switch.

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 over ride 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 override momentary to ignore momentary voltage and frequency transients during initial genset loading.

• Switch position indicating contacts (rated 10 amps 250VAC, 32VDC). (1) for Normal position, (1) for Emergency position.
• Gold plated engine start contacts (rated 5 amps 28VDC or 120VAC).

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.