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Automatic Transfer Switch
400 amp 3 pole
with PowerCommand microprocessor control


The OTEC Open Transition Transfer Switch by Cummins Power Generation provides dependable load transfer for emergency and standby applications.  Featuring an easy-to-use microprocessor-based control panel, this switch provides reliable and cost-effective load transfer between a utility service and generator set.

Standard Features

* Open transition load transfer with selectable phase check or programmed transition.
* 3-phase voltage sensing on the normal source; single phase sensing on the generator.
* Front panel indicators and push buttons for ease of set-up.
* Simple-to-read control panel that features universal symbols for easy status recognition.
* Adjustable time delays.
* Integral exerciser clock.
* UL/NEMA 1 indoor enclosure.
* UL Listed and CSA Certified.

Optional Features

* Service entrance rated disconnect
* Fully programmable exerciser clock.
* Elevator signal relay.
* Battery chargers.
* UL/NEMA 3R, 4, 12 enclosures.


Switch Current Rating 400 amps
Poles 3 pole with solid neutral
Voltage Rating 600Vac maximum
Transfer Time 6 cycles max at 60Hz with nominal voltage applied to actuator (without delayed transition enabled)
Operating Temperature -22F to +140F (-30C to +60C)
Operating Humidity 95% relative humidity, non-condensing
Altitude up to 10,000 feet without derating
Control Features (see notes below)

All setting adjustments are made by moving a slide switch on the back of the controller and using the touch pad on the front of the controller while observing the LEDs.  Detailed instructions contained in Owner Manual.

P.U. = pickup
D.O. = dropout
Function Adjustable Range Factory Setting
start time delay1 0-10 sec adj 3 sec
transfer time delay2 0-300 sec adj 5 sec
retransfer time delay3 0-30 minutes adj 10 minutes
stop/cool down delay4 0-30 minutes adj 10 minutes
neutral position delay
(600A switch & above)
0-64 sec 10 sec
under voltage sensing of utility5 70-90% D.O. adj
90-95% P.U. adj
85% D.O.
90% P.U.
frequency sensing of utility  ---  ---
voltage sensing of generator (1 leg) 75% D.O.
90% P.U.
frequency sensing of generator 75% D.O.
90% P.U.
generator test with or without load without
generator exercise with or without load
7-28 days
28 days
Options Included - 2 amp battery charger
- Two contacts (one for each source) are provided for customer use. Wired to terminal block for easy access. Rated at 10A continuous and 250 Vac maximum.
Other Options Available at additional cost
(partial listing)
- 40A, 70A, 125A, 150A, 225A, 260A, 300A,
   400A, 600A, 800A, 1000A ratings
- 120VAC through 600VAC
- 4 pole with switched neutral
- 50Hz
- 3 phase 3 wire or 4 wire
- type 3R, 4, 12 enclosures
- service entrance rated disconnect (through 800A)
Lug Capacities see spec sheet above
Enclosure UL type 1 indoor (types 3R, 4, 12 optional)
Nominal Dimensions (H x W x D) see spec sheet above
Weight see spec sheet above

1The start time delay prevents nuisance generator starts during momentary utility power variations.
2Transfer time delay allows generator set to stabilize before load is applied.
3Retransfer delay prevents needless power interruption if return of utility power is momentary.
4Stop delay allows gradual generator set cool down.
5Undervoltage sensing of utility supply provides reliable starting of generator set during brownout conditions.

This switch is available with service entrance rating as an optional adder.  Without this option you normally will need a service entrance rated disconnect between this switch and your power company meter.




Item Number: OTEC400
Price: $3,086
Price last updated 6/9/2022
Shipping Weight: 225 lbs.
This item normally ships in approximately 20 weeks or less.


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