Toshiba 1500 Plus manual 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

		Bypass circuit
Power
input plug	Fuse	UPS
		main
		circuit

IEC-320

Input

Transformer

+

UPS batteries

-

*Isolation only	UPS
for 1500 plus	receptacles
series (600VA)	(rear panel)

Output

Transformer

IEC-320

= 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
						*Isolation only
						for 1500 plus
						series (600VA)
	Fuse	Rectifier/
Input				Inverter		Output
		Charger/
		Chopper				Output
		Input				Output
		Transformer				Transformer
				+
				Batteries
		Low Battery	Overheating		Current Limit	Overvoltage/
		Level			Overload	Undervoltage
				5 - 2