Vertiv 10H92873, Installation And Operating Instructions Manual

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10H92873 - rev. 8 - 01/2019 - pag. 12
The following figures shows an example of NO SYNC (Fig. 11) and SYNC (Fig. 12):
Fig. 11 -
Synchro Error 88,56 [°]
Fig. 12 -
Synchro Error 0 [°]
When there is NO SYNC we need to determine the offset between the two wave forms, in the example of "Fig.
11" there is a difference of 88,56°.
In order to ensure a correct synchronisation we will enter a value in PNU 67.1, this is our offset.
To calculate the offset value:
PNU 67.1 = phase-error [°] * 65536 / 360
PNU 67.1 = 88,56° x 65536 / 360
PNU 67.1 = 16121
NOTE:
If by using this formula you are not able to compensate the offset, try with the following formula:
PNU 67.1 = (360 - phase error [°]) * 65536 / 360
After having calculated the new value for PNU 67.1, please proceed with following steps to change it:
• Close QS2 on this first UPS, wait for the Warning W2 - Bypass Switch Open - to be cleared;
• Stop the inverter;