Toshiba 1500 SERIES Operation Modes Circuit-bypass mode, Power flow in circuit-bypass mode

TOSHIBA

5.0Operating the UPS

5.1 Operation Modes

5.1.3 Circuit-bypass mode

Power input plug

Fuse

Bypass circuit

UPS receptacles

(rear panel)

UPS main circuit

5-15P	Transformer
	(Plus Series)		5-15R
	UPS batteries	+	= power flow
		-

Power flow in circuit-bypass mode.

If the UPS unit is severely overloaded or develops an internal fault, the power flow is automatically switched from the unit's main circuit to the bypass circuit mode. Power flow through the bypass is shown in the above illustrations. This change- over occurs automatically in approximately 4 milliseconds. The switching period is not long enough to cause interruptions to occur in most UPS equipment loads.

The energy flow must be transferred manually from the UPS's bypass circuit back to the inverter circuit after first correcting the fault. Toggle the STOP/RUN switch (on the unit's front panel) first to STOP and then back to RUN. This procedure resets the UPS and transfers back to inverter. During circuit- bypass mode the AC-Input LED is ON, the On-Line LED is OFF, and the Fault LED may be ON or OFF.(See Section 9.2 Panel Layout).

5.2System Protection Features

The schematic shown below depicts the electrical locations of the protection devices on the UPS.

Input	Overcurrent
Abnormal

	Fuse		Rectifier/
Input				Inverter	Output
			Charger/
			Chopper		Output
		Transformer
		(Plus Series)	+

Batteries

–

Low Battery Level

Overheating

Current Limit Overload

Overvoltage/ Undervoltage

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