MGE UPS Systems Different types of Galaxy PW systems, Isolation and protection devices

User’s Manual

different types of Galaxy PW™ systems

single-UPS unit

A	B
1
	D
	C
2

Fig. 2

parallel UPS system

See figure 3 showing two parallel-connect- ed (redundant) UPS units.

		Q3BP
	1	Q5N
S	2
2		Galaxy 1
	1
	2	Galaxy 2

Fig. 3

When increased power is required (two to four parallel units), an external bypass must be added (see figure 4).

		Q3BP
	1	Q5N
2	2
		Galaxy 1
	1
	2	Galaxy 2
	1
	2	Galaxy 3
	1
	2	Galaxy 4

Fig. 4

isolation and protection devices

(See figure 1 on previous page):

■Q1 (Molded circuit breaker NA):

❏isolation of the rectifier/charger (A) from the normal AC source (1);

❏rectifier/charger (A) start-up;

■QF1 (circuit breaker):

❏battery (D) protection and isolation; ■ Q5N (switch):

❏isolation of the UPS (B) from the load; ■ Q4S (switch):

❏isolation of the static bypass (C) from the bypass AC source (2);

■ Q3BP (switch):

❏bypass switch for maintenance;

■FUE (fuses):

❏protection of the rectifier/charger (A) from the normal AC source;

■ FUS (fuses):

❏protection of the inverter (B) from the load.

Note:

■switch Q3BP is lock on open position on parallel UPS systems constituted to increase available power.

external bypass for parallel UPSs and the hot-swap option

See figure 4.

■Q5N: isolation of the inverters of all the parallel UPS systems from the load;

■Q3BP: bypass for maintenance.

Introduction 5