KNOWLEDGEBASE
Item #: 1266 |
Created: 4/1/2013
Categories: Power Meter - PZ4000, Power Meter - WT1600, Power Meter - WT1800, Power Meter - WT3000
Why Does the Measurement of Inverter Efficiency Exceed 100%?
Solution:
This could be caused by any of the following:
- Is there any crosstalk (especially around the 2nd order)?
- Are there any effects of CMRR (especially around the 2nd order)?
- Is the location of measurement immediately next to the inverter I/O?
- Is the measuring lead too long?
- There are cases where switching the measuring lead from shielded cable to twisted pair can reduce the influence of noise.
- It is best to keep the measuring leads away from the ground or reference potential (to prevent capacitive coupling with the GND).
- If using a CT, there are cases when you should disconnect from ground.
- Is the input too small relative to the rating of the PT or CT current sensor?
- Is the combination of PT, CT, or current sensor and power meter range appropriate?
- Is the sync source setting the same for all inputs (the setting can be unified on the WT1600 and PZ4000)?
