UPS 120, UPS 150, UPS 250, UPS 300, UPS 301, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supplies Caterpillar

System Output Current Calibration MMS

The MMS current must be calibrated whenever the following are replaced:

• AC interface PWA (ACI)

• APS PWA (APC)

• Parallel controller cabinet PWA (PCC)

Note: "System Voltages" calibration is also required.

1. Read the Notice above.

2. Connect a computer to the UPS. Refer to Systems Operation, Testing and Adjusting, RENR9988, "PC to UPS Connection".

3. Place the UPS into INTERNAL BYPASS.

   SMS refer to Systems Operation, Testing and Adjusting, RENR9988, "SMS Internal and Maintenance Bypass".

   MMS refer to Systems Operation, Testing and Adjusting, RENR9988, "MMS Internal and Maintenance Bypass".

4. In UPSView, Click on the "Calibrate" on the tool bar.

5. Select "System Out Current" menu item.
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   Illustration 1	g01272735
   System Out Current

6. A "Calibration of a Channel" window will open. Click on "View Status" button. Another "Calibration Status" window will open. Drag the window aside if the window blocks the view of the "Calibration of a Channel" window. Click on "Use Defaults" on "Calibration of a Channel" window.

   You will be prompted to "Enter Calibration Point" for "System Output Current Phase A".

7. Apply a load to the system.

8. Measure the "System Out Current" at "Phase A".

9. Enter this value in "Enter Calibration Point" field.
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   Illustration 2	g01272792
   System Output Current pH. A

10. Click "OK".

    The System will process the Calibration and automatically prompt the user to "Enter Calibration Point" for "System Output Current Phase B".

    The "Calibration Group Status" window will display "Calibration complete but not saved" for "System Output Current Phase A".

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    Illustration 3	g01272827
    System output current phase B

11. Measure the "System Output Current" from "Phase B" bus.

12. Enter the value in "Enter Calibration Point" field.

13. Click on "OK".

    The System will process the Calibration and automatically prompt the user to "Enter Calibration Point" for "System Output Current Phase C".

    The "Calibration Group Status" window will display "Calibration complete but not saved" for "System Output Current Phase B".

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    Illustration 4	g01272835
    System output current phase C

14. Measure the "System Out Current" from "Phase C" bus, and enter this value in "Enter Calibration Point" field. Click on "OK".

    The System will process the Calibration and automatically prompt the user to "Enter Calibration Point" for "System Output Current Phase A" again.

    The "Calibration Group Status" window will display "Calibration complete but not saved" for "System Output Current Phase C".

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    Illustration 5	g01272839
    "System Current - Calibration complete but not saved"

15. Click on "Save".

16. To end the calibration session in UPSView, click "Connection" that is located on the menu bar and select "Disconnect". You will stop receiving the telemetry data.

17. Unplug the "RS232" cable from the system I/O and isolation board. Replace the Sheet Metal.

18. Close the doors for proper air flow into the system.