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UPS for 480 Vac Grid, User Guide, doc. rel.4.0
The corrected measurements are applied.
6.
Repeat the process for each dc-dc block, one block at a time, turning off all the dc blocks
except the one being calibrated.
8.2.3.3.
Charger current calibration
Use this function if it necessary to recalibrate the ampere readings of one of the UPS's input
phases.
In order to calibrate the charging current, you must ensure that there is charging current. This can
be done by manually
invoking
a battery test (
Main > Operation > Battery Test > Test Battery
)
shortly before you perform the calibration, to lower the battery voltage below its normal level.
For your reference, the present UPS-measured values are displayed on the right side of the
screen.
Calibration of the charger current should be performed when the system is under
a very light load or no load. This will insure maximum current to the dc converter
module.
To calibrate the UPS’s display of the charger current:
1.
With the UPS in normal mode, turn off the ac input (Main > Operation > Turn ON/OFF >
Modules Off > Select All > Inverter Off).
2.
Turn off all dc-dc blocks except for one (Main > Operation > Turn on/off > Dc-dc ON/OFF).
It is recommended you calibrate the dc-dc blocks starting with the bottom-most block (see
Figure 54).
3.
The battery bus is located inside the lower part of the UPS (Figure 52). Using a calibrated
ammeter, measure the actual dc current between the negative (“–“) battery bus and the
midpoint bus.
4.
Compare your measured value to the number to the right of the screen, which is the UPS’s
measurement. If your measured value differs from the UPS’s measured value, enter your
measured value into the field labeled “Charger negative” (see Figure 53).
5.
Next, measure the voltage between the positive (“+“) dc bus and the midpoint bus bar. If your
measured value differs from the UPS’s measured value, enter your measured value into the
field labeled Charger positive.
