4. Configuration and Operation
4.1.2
Automatic Transfer Switch Source Selection
The PDU will power up if one of the input sources is greater than the minimum startup voltage. In
normal operation (after power-up), if the presently selected source (primary or secondary) degrades
to a lesser condition, the unit should switch to the alternate source, if that source is of better
quality. The unit prefers the primary source, and will always switch to it in the event that both
sources are of the same (fair or good) quality. If the present source is becoming bad and the
alternate source is at least fair, the unit will switch to the alternate source.
Minimum Startup Voltage
Good Voltage Range
Fair Voltage Range
Bad Voltage Range
4.1.3
Quick Test
After installing the PDU and connecting
equipment, you may test the Automatic
Transfer Switch function by temporarily shutting
down the UPS system connected to the
Primary AC input. When the Primary input UPS
is no longer supplying AC power, the PDU will
switch from the Primary input to the Secondary
input, and the Secondary input LED will
illuminate. When the Primary input UPS has
been restarted and resumes supplying AC
power, the PDU will switch back to the Primary
input.
Note: The primary and secondary inputs must be connected to separate sources of utility power. The automatic
transfer switch function will be compromised if the primary and secondary inputs are connected to the same
utility power source. Do not perform a test with equipment that must remain in productive operation. Any test
procedure must prepare for the contingency that the equipment may lose power. Do not test the PDU by
detaching power cords which are connected to live power sources, as this eliminates the connection to ground
and places your equipment at risk.
19-04-221-933721.indb 11
Nominal Voltage of PDU
Low-Voltage Models
120V
85V
99-139V
75-98V
0-74V
Primary Input Active
11
High-Voltage Models
200-208V
220-240V
163V
163V
172-241V
190-266V
144-171V
144-189V
0-143V
0-143V
Secondary Input Active
6/10/2019 1:40:46 PM