APU-3 Auxilary Switchover Device

APU-3 Auxiliary Switchover Device

The APU-3 is an auxiliary power switchover device designed for instrument metering applications. In the event of power loss to the meter from the primary source, the APU-3 automatically switches the meter potential to one of three auxiliary sources. By using this approach, potential loss of revenue is avoided.

The application for the APU-3 are metering configurations where 2-4 service panels are provided to the customer, but meter potentials are only on one service. To insure that the meter is always energized and measuring energy use, the APU-3 switches from the primary source to 1 of 3 auxiliary sources if the primary source is lost.
The APU-3 is for 120VAC applications and allows for up to 3 alternative power sources to be connected and ready. Upon power loss from the primary (normal) source, the APU-3 automatically switches to the “1st Alternative” power source. If the 1st alternative power source drops out, the APU-3 will automatically switch to the “2nd Alternative” power source and so on. The APU-3 will always select the highest Alternative power source available and will always run (or switch back to) the normal power source if it senses 120 VAC present.

The same phase of each service should be used to insure that there is no potential difference between the phases if they are all powered. The APU-3 comes mounted inside an 8” wide x 8” high x 4” deep NEMA 1 enclosure.


Power Input: APU-3 –120 VAC
Output Voltage: APU-3 –120 VAC
Output Current: 3 Amp Max

Mounting: Any position
Size: 8” wide,  8” high,  4” deep

7 pounds

Temperature Range:

-38º C to +70º C, -38.4º F to +158º F

Humidity: 0 to 98% non-condensing

All specifications are subject to change without notice.