APC 6000 user manual Parallel connected UPS with Static Switch cubicle, UPS without Mains

UPS theory of operation (continued)

Parallel connected UPS with "Static Switch" cubicle

Up to six parallel connected rectifier-inverter cubicles can be combined with one "Static Switch" cubicle to form a system that

The units have separate batteries:

static by-pass switch

operates like a unitary UPS system. Each parallel connected rectifier- inverter cubicle houses a:

◗rectifier-charger;

◗battery;

◗three-phase inverter. The "Static Switch" cubicle contains:

◗static by-pass switch;

◗maintenance bypass.

Mains 2

rectifier- charger

Mains 1

rectifier- charger

Mains 1

inverter

battery inverter

load

battery

UPS without Mains 2

All UPSs without Mains 2 contain the same sub-assemblies:

◗rectifier-charger;

◗battery (option);

◗three-phase inverter.

They may or may not be parallel connected depending on type and may or may not contain a battery. The output voltage has a frequency of 50 or 60 Hz.

Operation without battery

Mains 1 power up:

◗the inverter receives power from the rectifier-charger and supplies power to the load. There is no direct connection between Mains 1 and the load.

Mains 1 power down:

◗no power to the load.

Maintenance position (disconnected):

◗no power to the load (except in parallel connected systems, where other units supply power).

rectifier-

chargerinverter

Mains 1 load

rectifier-

chargerinverter

Mains 1 load

rectifier-

chargerinverter

Q1	Q5N
Mains 1	load

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