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RIDMT: Reset Inverse Definite Minimum Time
Characteristic
RIDMT curves are used to obtain the inverse D.M.T. resetting characteristics for IEEE/ANSI and
custom curves that are needed to provide selectivity schemes when electromechanical relays are
protecting a primary line in series with the one CPM 310 G protects. The RIDMT parameters differ
with the tripping curve, the
Table of CPM 310 G Protection and Reset Curves Parameters
on page 22
shows these parameters. The sample image below shows the CO2 short time inverse trip
characteristic and it RIDMT curve. The formula below is to calculate the reset delay for CO2 RIDMT
curve. □
𝒕 =
[
𝟔. 𝟗 𝒔
𝟏 − (
𝑰
𝑰
𝑺
)
𝟐
]
× 𝑹𝑻𝑴𝑺
Sample RIDMT Curve: CO2 RIDMT Reset Curve
For other RIDMT curves, see the table at p.22
Summary of Contents for CPM 310 G
Page 1: ...CPM 310 G Digital Overcurrent Protection Relay User Application Manual vEN 2016 03...
Page 2: ...2...
Page 6: ...6 ABOUT DEMA...
Page 11: ...11 INTRODUCTION...
Page 32: ...32 PACKING LABELING INFORMATION...
Page 34: ...34 OPERATING MANUAL...
Page 53: ...53 RELAY MENUS MANUAL...
Page 55: ...55 The Menu Tree...
Page 56: ...56...
Page 57: ...57...
Page 58: ...58...
Page 59: ...59...
Page 60: ...60...
Page 61: ...61...
Page 128: ...128 DIGICONNECT PC PROGRAM MANUAL...
Page 189: ...189 APPLICATION DIAGRAMS...
Page 191: ...191 Sample Power Transformer Protection Application Diagram...
Page 193: ...193 FUNDAMENTAL CABLING DIAGRAM...
Page 203: ...203 APPLICATION DIAGRAM NO 10 RS485 Cabling...
Page 204: ...204 TECHNICAL DATA...
Page 220: ...220 GLOSSARY...