Yokogawa PR300 Power and Energy Meter - Manual (Page 26)

<Toc> <Ind> <3. Procedures for Setting PR300 Functions>
3-3
IM 77C01E01-10E
3.1.2 Setting of CT Ratio
[Procedure]
(1) Write a CT ratio to the two D registers in the table below. The data type is 4-byte
floating point.
(2) After writing that value, write 1 to the setup change status register, D0207.
D Register
D0203
D0204
D0207
Reference No.
40203
40204
40207
H No.
00CA
00CB
00CE
Description
CT ratio (float, lower 2 bytes)
CT ratio (float, upper 2 bytes)
Setup change status
(D0201 to D0206 are validated)
Effective Range
0.05 to 32000
If other than 1: Invalid
If 1: Writing is executed
Initial value of CT ratio: 1 (4-byte floating-point data: 3F800000)
[Example]
To set the CT ratio to 10.0:
For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
If 10.0 is converted into a 4-byte floating-point value, the value is 4120 0000.
[Command]
[STX] 01010WRW03D0203, 0000, D0204, 4120, D0207, 0001 [ETX] [CR]
[Response]
[STX] 0101OK [ETX] [CR]
NOTE
• When changing the CT ratio, the integrated values of active energy, reactive energy,
apparent energy, optional active energy, and regenerative energy will return to “0.”
The values of the demand alarm point and the scaling of analog output will also be
initialized.
• Set the VT and CT ratios so that [secondary rated power]
×
[VT ratio]
×
[CT ratio] is
smaller than 10 GW. When this value is 10 GW or greater, writing to D registers will be
invalid (no error is output).