APC 6739380EN/JC user manual Isolation and protection devices, UPS or converter cubicles

Introduction (cont.)

Isolation and protection devices

UPS or converter cubicles

(figure 8)

◗Q1 (switch):

◗isolation from Mains 1,

◗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.

Example of a single-unit UPS or single modular UPS

Q3BP

		Q4S	static switch
mains 2
	rectifier-
				inverter
	charger
Q1						Q5N
mains 1						load
FU1-2-3		QF1			FU5-6-7
			battery

Fig. 8

Static Switch Cubicle
(figure 9)					Q3BP
◗ Q4S (switch):
◗ isolation of the static switch (and
mechanical contactor K2S) from			static switch
Mains 2;
			Q4S
◗ Q3BP (switch):	mains 2
◗ bypass switch for maintenance;
◗ Q5N (switch):
◗ isolation of the load from the parallel					Q5N
UPSs;	parallel
					load
◗ Q1 (fuse switch):	UPSs
◗ protection of the cubicle control		Q2
electronics from the parallel-connected		Q1		control
inverter outputs;				electronics

◗Q2 (fuse switch):

◗protection of the cubicle control

electronics from Mains 2. Fig. 9

External maintenance bypass cubicle (figure 10)

◗Q3BP (switch):

◗bypass switch for maintenance;

◗Q5N (switch):

◗isolation of the load from the parallel- connected UPSs.

Q3BP

maintenance bypass line

	Q5N
parallel	load
modular UPSs

Fig. 10

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