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 f requency 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
Q1 Q5N
QF1
FU1-2-3 FU5-6-7
Q3BP
Q4S
parallel
UPSs load
static switch
mains 2
Q1
Q5N
Q3BP
Q4S
control
electronics
Q2