APC 9000 User Manual

34006452EN/AC

 - Page 30 

Shutdown

Modular UPS with external maintenance bypass  

 Frequency converters 

(no Mains 2)

 

– shutdown each UPS (see section "shutdown of 
a unit");

– transfer to the maintenance bypass in the order 

indicated below (the load is supplied directly by 
Mains 2 via bypass 

switch Q3BP):

– in the maintenance bypass cubicle, close 
switch Q3BP, then open switch Q5N;

– open output switch Q5N for each UPS;

– cut the Mains 2 supply to each UPS by opening 
the upstream protection devices;

– open battery circuit breaker QF1 on each UPS;

– open input switch Q1 on each UPS;
– the UPSs are de-energised once the capacitors 

have discharged.

Multi-bypass modular UPS  

– shutdown each UPS (see section "shutdown of 

a unit");

– the load is supplied via the Mains 2 of each 
UPS;

– close switch Q3BP on each UPS, the load is 

supplied by the Mains 2, via the bypass lines 
(Q3BP) of each UPS;

– open switches Q5N, Q4S, Q1 and QF1 on each 

UPS, the situation is that shown in the figure 
opposite;

– the UPSs are de-energised once the capacitors 

have discharged.

Shutdown of the inverters results in the interruption of the load;

– shut down each inverter (see the "shutdown of a unit" section);
– open battery circuit breaker QF1 and Mains 1 input switch Q1 on each unit;

– the system is powered down (except the Mains 1 cables upstream from switch Q1). A full powering down requires the 
opening of the upstream protection device on Mains 1.

Q1

Q5N

QF1

Q3BP

Q4S

Q1

Q5N

QF1

Q4S

Q5N

load

battery

inverter

mains 1

rectifier-

charger

static switch

mains 2

battery

inverter

mains 1

rectifier-

charger

static switch

mains 2

Q1

Q5N

QF1

Q3BP

Q4S

Q1

Q5N

QF1

Q3BP

Q4S

load

battery

inverter

mains 1

rectifier-

charger

static switch

battery

inverter

mains 1

rectifier-

charger

static switch

mains 2

Q1

Q5N

ON OFF

(I)

(0)

ON

(I)

QF1

OFF

ON

(0)

(I)