Vertiv 10H92873, Installation And Operating Instructions Manual

Page: 14 / 202

10H92873 - rev. 8 - 01/2019 - pag. 10
In order to ensure a correct synchronisation we will enter a value in PNU 75.21, this is our offset.
To calculate the offset value:
PNU 75.21 = phase-error [°] * 65536 / 360
PNU 75.21 = 88,56° x 65536 / 360
PNU 75.21 = 16121
NOTE:
If by using this formula you are not able to compensate the offset, try with the following formula:
PNU 75.21 = (360 - phase error [°]) * 65536 / 360
After having calculated the new value for PNU 75.21, 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;
In PPVis -> Parameter Input -> "[14] P75 Inv Special Performance Class", set the following parameters:
• PNU 51 "Access level CU" set to "Experts - Level 3 (3)";
• PNU 799 "SF - Super service" set to "SF 4 (4)";
• PNU 52 "Function selection CU" set to "H/W Init - URL (2)";
• PNU 75.21 "X_UR2_CRE" set to "the new calculated value" (16121 in our example);
Send all the parameters according to the list above (use the send pushbutton);
Once the parameters are at the "Actual Value" return to normal operation as follows:
• PNU 52 "Function selection CU" set to "Return (0)";
• PNU 799 "SF - Super service" set to "SF 0 (0)";
• PNU 51 "Access level CU" set to "Normal Operation - Level (1)";
• Start the inverter and open QS2 again, check that the SYNC is now according to example in "Fig. 9";
• Close QS2 again;
• Procedure complete for UPS1;
NOTE:
This offset compensation procedure must be followed for ALL the units connected to ESB.