Introduction (cont.)

Operation with the normal AC source restored

See figure 9.

When normal AC source power (1) is restored or its voltage returns to within specified tolerances, the system automatically returns to its normal operating mode described above (on the condition it did not reach the end of battery power). If the end of battery power was reached (with the resulting inverter shutdown), the rectifier/charger

(A)restarts automatically, but the inverter (B) must be restarted manually. The rectifier/charger recharges the battery (D) which was discharged during the mains outage. During battery charging, light 2 flashes green.

The message "BATTERY CHARGING" is displayed, together with the value of the recharging current and battery voltage.

The battery charge cycle takes place in two steps (see figure 10):

step 1: the battery is recharged at a constant current limited to 0.1C10 (i.e. 1/10th of the battery capacity specified for a 10 hour discharge). The DC voltage increases with the battery charge until the charge level is reached;

step 2: the battery is recharged at constant voltage equal to the charge level (maximum value 463 V).

The charging current gradually decreases until reaching a specified low value (floating current).

For vented lead-acid batteries, the rectifier/charger supplies the charging voltage for 0 to 255 hours (parameter defined by the after-sales support department) and then the floating voltage. For sealed lead-acid batteries, the charging and floating voltages are the same.

Note 1:

If the normal AC source failure is shorter than 0 to 255 seconds (default value = 30 seconds) (parameter defined by after-sales support department), the charger automatically supplies the floating voltage given the low battery discharge.

Note 2:

In frequency converters without battery power, the return of normal AC source power results in the automatic restart of the rectifier/charger and the inverter.

1

2

4

5

1

 

 

 

2

 

 

 

 

A

B

 

1

 

 

 

 

 

D

 

 

 

C

 

2

 

 

 

Fig. 9

Battery charge cycle

U/I

voltage

U charge/floating

 

(sealed batteries)

 

 

U "floating"

 

 

(vented batteries)

 

0,1 C10

 

 

current

 

current

constant voltage

t

limiting

decreasing current

 

Fig. 10

E-51028230XT/BG - 9

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Image 9
APC 20 - 200 KVA user manual Operation with the normal AC source restored, Battery charge cycle