Emerson 250-400kVA manual Until a service visit has been made and action taken

			UPS Alarm and Status Messages
Table 7	Liebert NXL alarm and status messages (continued)
Event Message		Event Definition	Recommended Action
		The output power factor is low.
		The output power factor is less than 70% leading
		or lagging. A simplified explanation of power
		factor is the ratio of energy being supplied to
		energy being used by the load. For a given load,
		the current output of the UPS goes up as power
		factor decreases.
		This results in the UPS output being derated.
		For example, study the following:
		Load = 100 kw @ 480V
		amps = kw X 1000 / volts X power factor X 1.73
		(square root of 3)	Press “SILENCE” to silence the audible alarm.
		100kw X 1000 = 100000
			Evaluate the load on the UPS. For more
Low Power Factor		480volts X .9PF X 1.73 = 747.36
			information, contact your factory-authorized service
		100000/747.36 = 133.8 amps
			provider.
		Now, replace the .9 power factor (typical
		computer load power factor) with .7 power factor:
		100kw X 1000 = 100000
		480volts X .7PF X 1.73 = 581.28
		100000/581.28 = 172 amps
		The load remains the same, but the current
		required to supply it is roughly 30% higher. The
		extra current is wasted energy that can result in
		nuisance trips of breakers, overheating of cables,
		and other unwanted conditions. The UPS cannot
		control the output power factor.
		This alarm is notification to the
			Press “SILENCE” to silence the audible alarm.
			Contact your factory-authorized service provider.
			If communications are reestablished, the One-Line
			Display will be restored; however, Liebert does not
		The UPS has transferred to Bypass due to a loss	recommend attempting to return the load to inverter
			until a service visit has been made and action taken
		of communications with the Main Controller.	to determine why the fault occurred.
		All Transfers, Startup, Shutdown, and Metering
			Action will involve resetting the UPS controls by
Main Control Fault		screens are locked out.
			removing and then reapplying control power.
		The Controls attempt to reestablish
			Therefore, it will be necessary to utilize
		communications but will not return the load to
			maintenance bypass, either by closing the optional
		inverter automatically.
			CB3 internal bypass breaker, or by closing the
			optional external Maintenance Bypass Breaker
			(MBB). Liebert does not recommend the user, or
			operator, attempt this without first speaking with an
			authorized service associate from Liebert.
Maintenance		The maintenance bypass breaker indicates that it
Bypass Breaker
		is in the open position
(MBB) Open
			The condition clears from the Active Event Window
			when manual re-transfers are enabled.
			A possible reason for this condition is an unstable
		This summary event means the conditions	generator. If the generator frequency is not stable,
			or not at 60 Hz, the Inverter may have difficulty
		required to perform a manual transfer to Inverter
			maintaining or acquiring synchronization with the
		(online) are not met (Inverter must be in sync with
			bypass source.
Man Rexfer Inhibit		bypass).	To check the synchronization of the Inverter to
		This status message is self-clearing. When the
		condition is no longer present, the message and	bypass, click “Transfer” and observe the
			synchroscope. A non-sync condition is indicated by
		any control activity tied to the status event reverts
			a varying phase angle error, rather than a stable “0”
		to normal.	degree indication.
			If the unit is not on generator, and the bypass
			voltage otherwise appears normal, contact your
			factory-authorized service provider.

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