GE T35 UR Series Instruction Manual page 310

5.9 TRANSDUCER INPUTS AND OUTPUTS
DCMA OUTPUT H3 SOURCE
DCMA OUTPUT H3 RANGE
DCMA OUTPUT H3 MIN VAL
DCMA OUTPUT H3 MAX VAL
The limit settings differ from the expected 0.7 pu and 1.1 pu because the relay calculates the positive-sequence quantities
scaled to the phase-to-ground voltages, even if the VTs are connected in "Delta" (refer to the Metering conventions section
in chapter 6), while at the same time the VT nominal voltage is 1 pu for the settings. Consequently the settings required in
this example differ from naturally expected by the factor of
The worst-case error for this application could be calculated by superimposing the following two sources of error:
• ±0.5% of the full scale for the analog output module, or
• ±0.5% of reading
For example, under nominal conditions, the positive-sequence reads 230.94 kV and the worst-case error is
0.005 x 230.94 kV + 1.27 kV = 2.42 kV.
5
5-188
: "SRC 2 V_1 mag"
: "0 to 1 mA"
: "0.404 pu"
: "0.635 pu"
T35 Transformer Protection System
3 .
± × ( ) ×
0.005 1 0 254.03 kV
–
5 SETTINGS
±
1.27 kV
=
GE Multilin