User Manual

79Rack ATS AP44xx User Manual
Configure switching behavior
Path: Configuration > ATS > Frequency/Voltage.
Frequency Deviation: Frequency deviation beyond the set value will cause the Rack ATS to switch
power sources.
NOTE: If the frequency is at 50 Hz (see “View power measurements” on page 74) and the Sensitivity is
set to High, this value should be 3 or 5.
Line VRMS: Rated voltage for the Rack ATS (also called Nominal Input). VRMS limits and transfer
ranges are based on this value.
Sensitivity: Control how much power fluctuation the Rack ATS tolerates before switching to the
secondary power source. With a Low sensitivity, the Rack ATS waits 4 milliseconds (ms) before
switching to the alternate power source. (This can help prevent excessive switching if your source
voltage has excessive or frequent fluctuation.) With a High sensitivity, the Rack ATS waits 2 ms before
switching to the alternate power source.
NOTE: If the frequency is at 50 Hz and the Frequency Deviation is set to 10, Sensitivity should be set
to Low.
Limits and Transfer Range: The Transfer Range is the Line VRMS plus or minus a configured Limit
(Wide, Medium, or Narrow). The Transfer Range determines the switching behavior for the Rack ATS
based on source voltage: when the source voltage moves outside the Transfer Range, the Rack ATS
switches to the secondary power source.
• VRMS Wide, Medium, and Narrow Limit: set configuration options for the Transfer Range.
• Transfer Range: Decide whether the Rack ATS will switch power sources based on the Wide,
Medium, or Narrow VRMS Limit. The Transfer Range can only be set to one Limit at a time.
Example: A Rack ATS is set to the following configuration:
Line VRMS = 208,
VRMS Wide Limit = 10,
Transfer Range =
Wide.
The ATS will switch sources when the voltage goes below 198 VRMS or above 218 VRMS (208 ±10
VRMS).
NOTE: The Voltage Transfer Range and Limit must remain within the absolute maximum ratings of the
Rack ATS: 85–265 VRMS. At any voltage below 85 VRMS or above 265 VRMS, the Rack ATS will
switch power sources regardless of configuration.
Click Apply to save your changes or Cancel to erase your changes.
DANGER
HAZARDOUS VOLTAGE
Do not operate the Rack ATS outside Rated Voltage (+/- 10%). Voltage limits and transfer
ranges represent software control of switching behavior, not input voltages for use.
Failure to follow these instructions will result in death or serious injury
.