Owner`s manual
Facility Circuit
Facility Circuit
PDUMH30AT
Critical Equipment
Loads
SecondaryUPS
PrimaryUPS
PrimaryInputCord
Secondary Input Cord
UtilityB
UtilityA
16
Configuration and Operation
Automatic Transfer Switch
WhenthePrimaryandSecondaryinputsarebothconnectedtoTrippLiteUPS
Systems,thePDUoperatesasanAutomaticTransferSwitch,providingredundant
inputpowerforhighavailabilityapplications.Undernormaloperatingconditions,the
PDUwilldistributepowerfromthePrimaryinputsource,switchingtotheSecondary
inputsourceundercertainconditions.ThePDUwillswitchtothePrimarysource
wheneveritisGoodaccordingtothePDUinputvoltagedefinitions(seebelow).
Preferred Configuration
The Automatic Transfer Switch function
provides increased availability when the
PrimaryandSecondaryinputsofthe
PDUareconnectedtoseparate
TrippLiteUPSSystemsthatare
connected to separate utility power
sources.Formaximumavailability,
Tripp Lite recommends using matching
SmartOnlineUPSSystemswithpure
sinewaveoutputforthePrimaryand
Secondary input power sources. The
automatic transfer switch function will
be compromised if the primary and
secondary inputs are connected to the
same utility power source.
Warning: DO NOT connect the primary input to a line-interactive UPS, due to
transfer time issues, or to any source that does not supply a pure sine wave.
Such sources may be used to power the secondary input.
Automatic Transfer Switch Source Selection
ThePDUwillpowerupifoneoftheinputsourcesisgreaterthantheminimum
startupvoltage.Innormaloperation(afterpower-up),ifthepresentlyselectedsource
(primaryorsecondary)degradestoalessercondition,theunitshouldswitchtothe
alternatesource,ifthatsourceisofbetterquality.Theunitpreferstheprimary
source,andwillalwaysswitchtoitintheeventthatbothsourcesareofthesame
(fairorgood)quality.Ifthepresentsourceisbecomingbadandthealternatesource
isatleastfair,theunitwillswitchtothealternatesource.
PDU Power Source Selection Parameters
PDUMH30AT&
PDUMH30ATNET
PDUMH30HVAT&
PDUMH30HVATNET
Nominal Voltage 120V 208V
Minimum Startup Voltage 85V 163V
“Good”VoltageRange 99-139V 172-241V
“Fair”VoltageRange 75-98V 144-171V
“Bad”VoltageRange 0-74V 0-143V
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