Datasheet

Data Sheet ADE7758
Rev. E | Page 43 of 72
START
CALIBRATE IRMS
OFFSET
CALIBRATE VRMS
OFFSET
MUST BE DONE
BEFORE VA GAIN
CALIBRATION
WATT AND VA
CAN BE CALIBRATED
SIMULTANEOUSLY @
PF = 1 BECAUSE THEY
HAVE SEPARATE PULSE OUTPUTS
ALL
PHASES
VA AND WATT
GAIN CAL?
YES NO
SET UP PULSE
OUTPUT FOR
A, B, OR C
CALIBRATE
WATT AND VA
GAIN @ I
TEST
,
PF = 1
ALL
PHASES
GAIN CAL
VAR?
YES NO
SET UP FOR
PHASE
A, B, OR C
CALIBRATE
VAR GAIN
@ I
TEST
, PF = 0,
INDUCTIVE
ALL
PHASES
PHASE ERROR
CAL?
YES NO
SET UP PULSE
OUTPUT FOR
A, B, OR C
CALIBRATE
PHASE @ I
TEST
,
PF = 0.5,
INDUCTIVE
ALL PHASES
VAR OFFSET
CAL?
YES NO
SET UP PULSE
OUTPUT FOR
A, B, OR C
CALIBRATE
VAR OFFSET
@ I
MIN
, PF = 0,
INDUCTIVE
ALL PHASES
WATT OFFSET
CAL?
YES NO
SET UP PULSE
OUTPUT FOR
A, B, OR C
CALIBRATE
WATT OFFSET
@ I
MIN
, PF = 1
END
04443-076
Figure 77. Calibration Using Pulse Output
Gain Calibration Using Pulse Output
Gain calibration is used for meter-to-meter gain adjustment,
APCF or VARCF output rate calibration, and determining the
Wh/LSB, VARh/LSB, and VAh/LSB constant. The registers used
for watt gain calibration are APCFNUM (0x45), APCFDEN
(0x46), and xWG (0x2A to 0x2C). Equation 50 through
Equation 52 show how these registers affect the Wh/LSB
constant and the APCF pulses.
For calibrating VAR gain, the registers in Equation 50 through
Equation 52 should be replaced by VARCFNUM (0x47),
VARCFDEN (0x48), and xVARG (0x2D to 0x2F). For VAGAIN,
they should be replaced by VARCFNUM (0x47), VARCFDEN
(0x48), and xVAG (0x30 to 0x32).
Figure 78 shows the steps for gain calibration of watts, VA, or
VAR using the pulse outputs.