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2 bypass mode, Bypass mode, Toshiba – Toshiba 4200FA CT/XT User Manual

Page 39

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TOSHIBA

6.2 Bypass

Mode

If the UPS unit is severely overloaded or develops an internal fault, power flow is automatically

switched from the main circuit to the Bypass circuit. Power flow through the bypass is shown in the

following illustration. This changeover occurs automatically in less than 4 milliseconds in phase

(Make-Before-Break). If the power flow is transferred to the Bypass circuit because of an overload

and that overload condition ends within a specified period of time, then the power flow will "re-

transfer" to the AC Input Mode (Normal Operation) automatically. If the power flow is transferred to

the Bypass circuit due to a fault condition, then the power flow must be transferred manually

from the UPS's Bypass circuit back to the Inverter circuit after repairing the fault

(see "Start-up

Procedure").

If the power flow is transferred to the Bypass circuit due to an overload condition,

then the power flow will automatically transfer from the UPS's Bypass circuit back to the

Inverter circuit after removing the overload

(see "Overload Operation").


Input

Power

Converter

Inverter

Bypass

Charger/
Chopper

Isolating

XFMR

External

Batteries

Output

Power

MCCB

MBS

Power Flow

Power flow in Bypass mode



6.3

Bypass Mode for Optional Alternate Input Models

Power flow in Bypass mode for the Alternate Input Models

Power Flow

Converter

Inverter

Bypass

Charger/
Chopper

Isolating

XFMR

External

Batteries

Output

Power

MCCB

MBS

Bypass

Power

Input

Power

4200FA CT/XT User’s Manual

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