APC 6739380EN/JC System shutdown, Single-unit or single modular, External maintenance bypass

System shutdown

Single-unit or single modular

UPS

◗shutdown the inverter (see the "shutdown of a module" section);

◗carry out operations in the following order:

◗close maintenance bypass switch Q3BP:

◗open Mains 2 input switch Q4S:

Q1 Q4S Q3BP Q5N

ON	ON	OFF	ON	OFF
(I)	(I)	(0)	(I)	(0)

Shutdown (cont.)

◗open Mains 1 input switch Q1:

Q1 Q4S Q3BP Q5N

ON OFF		OFF	ON	OFF
(I)	(0)	(0)	(I)	(0)

Q1 Q4S Q3BP Q5N

ON	ON	OFF	ON	ON
(I)	(I)	(0)	(I)	(I)

◗open output switch Q5N:

Q1 Q4S Q3BP Q5N

ON	ON	ON	ON OFF
(I)	(I)	(I)	(I)	(0)

◗open battery circuit breaker QF1:

QF1

ON OFF
(I)	(0)

◗the UPS is powered down (except the Mains cables upstream from switches Q1, Q4S and Q3BP) and the load is supplied by Mains 2. All the lights on the control panel are off. A full powering down requires load shutdown and the opening of the upstream protection devices on Mains 1 and 2.

Modular UPS with external maintenance bypass

◗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.

External maintenance bypass
	Q3BP
Modular UPS 1
Q4S	static switch
mains 2
rectifier-	inverter
charger
Q1	Q5N
mains 1
QF1
	battery
Modular UPS 2	load
	Q5N
Q4S	static switch
mains 2
rectifier-	inverter
charger
Q1	Q5N
mains 1
QF1
	battery
	6739380EN/JC - Page 25