Siemens 7SR242 Duobias - 2.4 Restricted Earth fault (64 H)

To Next Page

To Previous Page

7SR242 Duobias Commissioning & Maintenance Guide

2.4 Restricted Earth fault (64H)

Figure 2-6 Restricted Earth Fault

Voltage Inputs: n/a

Current Inputs: I

G1 ,

Disable: 50G, 51G, 50BF

Map Pickup LED: 64H-n - Self Reset

The external stabilising resistor value should be measured and compared to that specified in the settings data.

Both values should be recorded.

Element Settings Data: R

STAB

Value R

STAB

Measured

64H-1

64H-2

The relatively high value of stabilising resistance R

STAB

will often interfere with secondary current injection when

using a digital test set. It is normal practice in these cases to short circuit the resistor to allow testing, the shorting

link should be removed after testing.

Main Page

Document Release History1
Software Revision History1
Table of Contents2
Contents2
Section 1: Common Functions5
Overview5
Before Testing5
Safety5
Sequence of Tests5
Test Equipment6
Precautions6
Applying Settings7
Tests8
Inspection8
Secondary Injection Tests8
Primary Injection Tests8
Putting into Service8
AC Energising Quantities9
Binary Inputs10
Binary Outputs11
Relay Case Shorting Contacts11
Section 2: Protection Functions12
Biased Differential (87BD, 87HS)14
Secondary Injection Testing14
Figure 2-1 Biased Differential14
Figure 2-2 Secondary Injection Using a Variac15
Primary Injection Testing17
Phase Overcurrent (50, 51)18
Figure 2-3 Phase Overcurrent18
Definite Time Overcurrent (50)19
Inverse Time Overcurrent (51)19
Derived Earth Fault (50N,51N)21
Figure 2-4 Measured Earth Fault21
Definite Time Overcurrent (50N)22
Inverse Time Overcurrent (51N)22
ANSI Reset23
Measured Earth Fault (50G, 51G)24
Figure 2-5 Measured Earth Fault24
Definite Time Overcurrent (50G)25
Inverse Time Overcurrent (51G)25
ANSI Reset26
Restricted Earth Fault (64H)27
Figure 2-6 Restricted Earth Fault27
Open Circuit (46BC)29
Figure 2-7 Open Circuit29
Negative Phase Sequence Overcurrent (46NPS)31
Figure 2-8 Negative Phase Sequence Overcurrent31
Definite Time NPS Overcurrent (46DT)32
Inverse Time NPS Overcurrent (46IT)32
Undercurrent (37, 37G)34
37-N Elements34
Figure 2-9 Undercurrent34
Elements35
Thermal Overload (49)36
Figure 2-10 Thermal Overload36
Under/Over Voltage (27/59)38
Figure 2-11 Phase Under/Over Voltage38
Undervoltage Guard (27/59UVG)40
Neutral over Voltage (59N)41
Figure 2-12 Neutral Overvoltage41
Definite Time (59NDT)42
Inverse Time (59NIT)42
Under/Over Frequency (81)43
Figure 2-13 Under/Over Frequency43
Overfluxing (24)45
Definite Time (24DT)45
Figure 2-14 Under/Over Frequency45
Inverse Time (24IT)46
Section 3: Supervision Functions47
CB Fail (50BF)47
Figure 3-1 CB Fail47
Trip/Close Circuit Supervision (74TCS, 74CCS)49
Figure 3-2 Trip Circuit Supervision49
Magnetising Inrush Detector (81HBL2)50
Figure 3-3 Magnetising Inrush Detector50
Overfluxing Detector (81HBL5)52
Figure 3-4 Magnetising Inrush Detector52
Section 4: Control & Logic Functions53
Quick Logic53
Section 5: Testing and Maintenance54
Periodic Tests54
Maintenance54
Troubleshooting54
Defect Report Form56

Siemens 7SR242 Duobias - 2.4 Restricted Earth fault (64 H)

Table of Contents

Related product manuals