APC 9000 User Manual

34006452EN/AC

- Page 8

Introduction

1.4 Isolation and protection devices

UPS or converter cubicles

(figure 8)

Example of a single-unit UPS or single modular UPS

Static Switch Cubicle

(figure 9)

– Q1 (switch):

isolation from Mains ,

RC start-up;

– QF1 (circuit breaker):

battery protection and isolation;

– Q5N (switch):

isolation of the inverter, frequency converter or static switch module from the load;

– Q4S (switch):

isolation of the static switch from Mains 2;

– Q3BP (switch):

bypass switch for maintenance;

– FU1-2-3 (fuses):

protection of the RC from Mains 1;

– FU5-6-7 (fuses):

protection of the inverter from the load.

Note:

– switches Q4S and Q3BP do not exist on frequency converters,

– circuit breaker QF1 does not exist on frequency converters without a battery.

Fig. 8

– Q4S (switch) :

isolation of the static switch (and mechanical contactor K2S) from Mains 2;

– Q3BP (switch) :

bypass switch for maintenance;

– Q5N (switch) :

isolation of the load from the parallel UPSs;

– Q1 (fuse switch) :

protection of the cubicle control electronics from the parallel-connected inverter outputs;

– Q2 (fuse switch) :

protection of the cubicle control electronics from Mains 2.

Fig. 9

mains 1

load

rectifier-

charger

battery

inverter

static switch

mains 2

Q5N

QF1

FU1-2-3

FU5-6-7

Q3BP

Q4S

parallel

UPSs

load

static switch

mains 2

Q5N

Q3BP

Q4S

control

electronics