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Specification Sheet

ManualsBrandsCummins ManualsIndustrial EquipmentNon-Service Entrance OTEC125 Series Automatic Transfer Switch
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©2013 Cummins Power Generation Inc. | S-1639b (6/13)
Microprocessor control
• Simple, easy-to-use control provides transfer switch information and
operator controls
• LED lamps for source availability and source connected indication,
exercise mode, and test mode. LED status lamps also provided for control
set-up and configuration.
• Pushbutton controls for initiating test, overriding time delays and setting
exercise time.
• Field-configurable for in-phase open or programmed open transition.
• Integral exerciser clock
• Control is prototype-tested to withstand voltage surges per EN 60947-6-1.
•
Gold-flashed generator start contacts
Control functions
Voltage sensing: All phases on the normal source and single phase on generator source. Normal Source Pickup:
adjustable 90-95%, Dropout: adjustable 70-90% of nominal voltage; Generator Source Pickup: 90%, dropout: 75% of
nominal voltage.
Frequency sensing: Generator Source Pickup: 90% of nominal frequency; Dropout: 75% of nominal frequency.
Exerciser clock: Switch is furnished with an integral engine exerciser configurable for operation on a 7, 14, 21, or
28-day cycle with a fixed exercise period duration of 20 minutes. A 12-hr exerciser time offset allows for the
convenient setting of exercise time without the need to activate the timer at the exact time that you need to schedule
the generator exercise for. Software selectable capability allows for the exercising of the generator with or without
load.
Time delay functions
Engine start: Prevents nuisance genset starts due to momentary power system variation or loss. Adjustable: 0-10
seconds; default: 3 seconds.
Transfer normal to emergency: Allows genset to stabilize before application of load. Prevents power interruption
if normal source variation or loss is momentary. Allows staggered transfer of loads in multiple transfer switch systems.
Adjustable 0-300 seconds, default 5 seconds.
Retransfer emergency to normal: Allows the utility to stabilize before retransfer of load. Prevents needless power
interruption if return of normal source is momentary. Allows staggered transfer of loads in multiple transfer switch
systems. Adjustable 0-30 minutes, default 10 minutes.
Genset stop: Maintains availability of the genset for immediate reconnection in the event that the normal source fails
shortly after transfer. Allows gradual genset cool down by running unloaded. Adjustable 0-30 minutes, default 10
minutes.
Delayed (programmed) transition: Controls the speed of operation of the transfer switch power contacts to allow
load generated voltages from inductive devices to decay prior to connecting a live source. Adjustable 0-10 seconds,
default 0 seconds.
Options