APC 20 - 200 KVA user manual System description, System may also include

Introduction (cont.)

System description

(see figure 1)

◗ a rectifier/charger module (A)

converts 3-phase AC power from the

normal AC source supply (1) into DC

power for the normal inverter input and

float charges or recharges the battery;

◗ a battery unit (D) provides backup

power for the inverter in the event of a

voltage drop or a normal AC source

failure;

◗ an inverter module (B) converts the

DC power supplied by the rectifier/

charger module or the battery unit into

3-phase AC power for the load;

◗ a static bypass module (C) ensures

the instantaneous transfer of the load to

the bypass AC source input in the

event of an inverter shutdown (initiated

by the user or by a protective device) or

a sudden overload;

◗ a maintenance bypass isolates the

Note

◗the normal AC input and the bypass AC input have different functions and, depending on the installation, may be protected differently upstream and/or come from different sources.

◗frequency converters are available without backup batteries;

◗the static bypass line and the maintenance bypass line do not exist in installations where the load frequency and the bypass AC source frequency are different (for example in frequency converters);

◗when increased power is required, several MGE™ Galaxy™ PW units may be connected in parallel. In this configuration, an "isolation" function is added for the UPS system as a whole for maintenance purposes, without interrupting the supply of power to the load.

The system may also include :

◗an isolating transformer on bypass AC input;

◗a passive harmonic filter (FAH) on the normal AC input;

◗an active harmonic conditioner on the normal AC input;

◗different remote control, indication and display systems.

UPS for maintenance and transfers the

load to bypass AC source input without

interrupting the supply of power. The

maintenance bypass is made up of

three manual switches (Q3BP, Q4S

and Q5N).

Schematic diagram of the MGE™ Galaxy™ PW system

		rectifier/	inverter (B):
		charger (A):	DC to AC
		AC to DC	power	isolation and
		power
				protection:
	(1)			FUS	Q5N
normal					load
AC input	Q1	FUE :
	isolation
	and protection		QF1: isolation
			and protection
			battery (D):
			backup power
		isolation:
		Q4S	static bypass (C):
bypass	(2)
AC input
		maintenance bypass:
		Q3BP

Fig. 1

6 - E-51028230XT/BG