APC 9000

34006452EN/AC - Page 12

Introduction

Installation with an engine generator set (figure 15)

UPS shutdown or overload (systems with a static switch module) (figure 16)

Single-unit UPSs, modular UPSs or UPSs with an SSC:

Fig. 16

If a stand-by generator is included in the installation, it is generally started automatically in the event of a Mains failure and

connected to the main low voltage switchboard.

It is disconnected when Mains power is restored.

With such a system, the required battery time may be reduced to the time necessary for starting and bringing on line the

stand-by generator.

The battery supplies power to the inverter during the transfers: Mains- generator and generator - Mains.

The transfer sequences described: Mains- battery - generator and generator - battery - Mains are fully automatic.

They in no way affect the load and require no manual operation by the user.

Note:

To avoid load surges on the generator, the rectifier/charger is started with a 10 second maximum current consumption walk-in.

Example of an installation with an engine generator set

Fig. 15

– in the event of a UPS shutdown (initiated by the user or by an internal protective device), the load is automatically

transferred to the Mains2 bypass line. If transfer conditions are correct, transfer takes place instantly, without interruption to

the load.

Note:

Transfer conditions are not correct when Mains 2 characteristics are outside tolerances (voltage: ±10 %; frequency as per

personalization; phase sync with inverter ±3°);

– in the event of a major transient overload (greater than 160 % of the full load), immediate transfer tak es place as above,

without interruption to the load.

When the overload disappears, the load is automatically returned to the inverter depending on the configured value of the

re-transfer counter: no return to inverter, or 1 to 255 (personalized value) overloads accepted before the load is permanently

transferred to Mains2. This operating mode allows start-up of load devices causing high inrush currents.

This system requires correct transfer conditions. If the conditions are not correct, the inverter will current limit to 150 % of its

rated current for 1 second before stopping;

– in the event of a small but extended overload (i.e. a continuous level of power exceeding the full rated load), the inverter

will continue to supply power for a period depending on the magnitude of the overload (10 minutes for a 125 % overload,

1 minute for a 150 % overload). See figure 17 (Overload curve);

– in all three of the above cases, the inv erter shutsdown and supplies the load via Mains 2 with the following information

on the control panel:

– green "load protected" light off,

– buzzer on,

– red "load not protected" light on.

mains 2

mains 1

Galaxy

G

main LV

switchboard

generator

network

1

+

beep...beep...

mains 1

rectifier-

charger

battery

inverter

load

static switch

mains 2