MCP3909RD-3PH1 Microchip Technology, MCP3909RD-3PH1 Datasheet - Page 64

• Manufacturer Part Number: MCP3909RD-3PH1
• Description: REF DESIGN MCP3909 3PH ENGY MTR
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH1

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: No
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Primary Attributes: 3-Ph, 220 VAC, In Case, LCD, USB, GUI
• Secondary Attributes: Opto-Isolated Interface for Safety
• Operating Voltage: 220 V
• Operating Current: 5 A
• Description/function: Energy Meter
• For Use With/related Products: MCP3909
• Lead Free Status / RoHS Status: Not applicable / Not applicable

MCP3909 3-Phase Energy Meter Reference Design
6.8
DS51643B-page 60
METER CALIBRATION
One of the main functions of the software is to assist in meter calibration. This process
is accomplished by selecting the phase for calibration and clicking the “CALIBRATE”
button. The following steps will occur for a given phase:
1. Calibrate phase under configuration C1 as either a standard phase or a
2. Calibrate phase under configuration C2 for phase delay.
3. Calibrate phase under configuration C3 for active power offset.
4. Calibrate phase under configuration C4 for RMS offset.
For a meter to be entirely calibrated, all 3 phases must be calibrated separately, with
one of the phases being selected as the standard phase.
6.8.1
The first step is to apply VCAL and ICAL to a given phase and choose whether or not
this phase is being selected as the standard phase. The software will prompt the user
with this question and also instruct the user to apply the correct voltages and currents.
The software calculates the calibration registers through the equations defined in
Chapter 5. “Meter Calibration” and allows the user to input the exact voltages and
current for more correct calibration register numbers.
The following dialog window will appear in configuration C1:
FIGURE 6-3:
At this point, the software will default to the VCAL and ICAL values that are currently in
the meter design frame. The user can MODIFY these values to the exact currents and
voltages that are being read from the calibrated meter equipment present during
calibration. In the example above, the user modified the numbers 220 to be 220.23V
and 10A to be 10.15A.
Once the user selects the “OK” button, energy accumulation will occur and status can
be observed via the energy accumulation bar.
Section 5.3.3 and Section 5.3.5 describes the registers and equations that the soft-
ware uses to calibrate the meter.
non-standard phase.
Calibration Step 1 - Configuration C1
Calibration Step C1 with calibration settings input boxes.
© 2008 Microchip Technology Inc.