To adjust the scale factor of PM800, the procedure would be as follows:
Step 1) Write the value 9020 to register 8000 to enter the setup mode.
Step 2) Write the desired scale factor value to the appropriate register. The scale factor would be in the range of #3209 to 3215, there is a range each type of scale factor. Refer the attached extract of PM800 register list. e.g. if you want to change the 3 phase ammeter so that you can read up to 1 decimal. You have to write -1 as value for the register 3209 e.g. if you want to change the power so that you can read it as mega watt. You have to write 3 as value for the register 3214 Repeating this step for each subsequent scale factor change can change multiple scale factors.
Step 3) Write the value 1 to register 8001 to save the changes made in Step 2.
Step 4) Write the value 9021 to register 8000 to exit the setup mode. The power meter will reset. The power values will now be displayed on the Display of power meter with the new scale.