Installation with an engine generator set

Introduction (cont.)

Installation with an engine generator set

(figure 15)

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.

Example of an installation with an engine generator set

generator	main LV	Galaxy
	switchboard
G		mains 2
G
HV		mains 1
HV
network

Fig. 15

Note:

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

UPS shutdown or overload

(systems with a static switch module)

(figure 16)

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

◗ in the event of a UPS shutdown

(initiated by the user or by an internal

protective device), the load is

automatically transferred to the Mains 2

bypass line. If transfer conditions are

correct, transfer takes place instantly,

static switch

mains 2

rectifier-

chargerinverter

mains 1

battery

load

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 takes 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 Mains 2. This operating mode allows start-up of load devices causing high inrush currents.

Fig. 16

This system requires correct transfer conditions. If the conditions are not correct, the inverter will current limit to 160% 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 inverter shutsdown and supplies the load via Mains 2 with the following information on the control panel:

◗ green "load protected" light 5 off,

◗buzzer 1 on,

◗red "load not protected" light 2 on.

beep...beep...

!	!	+ –
		+ –

1 2

6739380EN/JC - Page 11