Using ADE7880, set to 3-phase, 4 wire configuration. Using the resistance load, I always get the negative xWATTHR values, positive xVAHR. I set to use the Line cycle accumulation mode to get these energy values.
Here is the settings (run in 60Hz):
1. Set LCYCMODE register to 0xBD; /* includes all 3 phases' half cycles */
2. Set LINECYC to 6*300 = 1800d (16.67ms * 300 = 5.001 seconds)
3. Set VLEVEL = 500.0 / 1.414 / 120.0 * 4 * 1000000 = 11786893
where voltage is set to the gain of 1, 120.0 is the expected phase voltage.. Is it the reasonable value???
4. WTHR / VARTHR / VATHR are the default value, didn't change them
Then, when LENERGY bit is set at STATUS0 register, MCU reads xWATTHR and xVAHR regiseters:
AWATTHR = 0XFFFFE170, the readings are consistent.
AVAHR = 0x00001E8F, the readings are consistent.
BWATTHR = 0XFFFFE230, the readings are consistent.
BVAHR = 0x00001DF2, the readings are consistent.
CWATTHR = 0XFFFFE1AC, the readings are consistent.
CVAHR = 0x00001E76, the readings are consistent.
Do I set up anything wrong, I expected to get all positive energy values? Is it right?
I wonder if the content of register VLEVEL caused this issue. What is the primary functionality on WTHR / VARTHR / VATHR? Do I have to set up these registers? On equation 26, 37, 44, how should I determine the value of "n"?
Thank you very much!