6 F 2 T 0 1 7 2
that has previously been loaded to 90% of its capacity.
Thermal Curves (Cold Curve - no
prior load)
0.01
0.1
1
10
100
1000
1
10
Overload Current (Multiple of I
AOL
)
O
p
er
at
e T
im
e (
m
in
u
tes)
Thermal Curves (Hot Curve -
90% prior load)
0.001
0.01
0.1
1
10
100
1000
1
10
Overload Current (Multiple of I
AOL
)
O
p
er
at
e T
im
e (
m
in
u
tes)
Figure 2.5.1 Thermal Curves
Scheme Logic
Figure 2.5.2 shows the scheme logic of the thermal overload protection.
The thermal overload element THM has independent thresholds for alarm and trip, and outputs
alarm signal THM ALARM and trip signal THM TRIP. The alarming threshold level is set as a
percentage of the tripping threshold.
The alarming and tripping can be disabled by the scheme switches [THMAEN] and [THMTEN]
respectively or binary input signal THM BLOCK.
T
A
THM
&
THM ALARM
THM BLOCK
1
+
"ON"
[THMAEN]
+
"ON"
[THMEN]
THM TRIP
&
77
78
Figure 2.5.2 Thermal Overload Protection Scheme Logic
τ
100
50
20
10
5
2
1
τ
50
20
10
5
2
1
37
Summary of Contents for GRE110
Page 183: ...6 F 2 T 0 1 7 2 Appendix B Signal List 184 ...
Page 191: ...6 F 2 T 0 1 7 2 Appendix C Event Record Items 192 ...
Page 196: ...6 F 2 T 0 1 7 2 Appendix D Binary Output Default Setting List 197 ...
Page 199: ...6 F 2 T 0 1 7 2 Appendix E Relay Menu Tree 200 ...
Page 210: ...6 F 2 T 0 1 7 2 Appendix F Case Outline 211 ...
Page 211: ...6 F 2 T 0 1 7 2 Case Outline for model 400 401 420 421 820 and 821 212 ...
Page 212: ...6 F 2 T 0 1 7 2 Case Outline for model 402 and 422 213 ...
Page 213: ...6 F 2 T 0 1 7 2 Appendix G Typical External Connection 214 ...
Page 245: ...6 F 2 T 0 1 7 2 Appendix J Return Repair Form 246 ...
Page 249: ...6 F 2 T 0 1 7 2 Customer Name Company Name Address Telephone No Facsimile No Signature 250 ...
Page 250: ...6 F 2 T 0 1 7 2 Appendix K Technical Data 251 ...
Page 256: ...6 F 2 T 0 1 7 2 Appendix L Symbols Used in Scheme Logic 257 ...
Page 259: ...6 F 2 T 0 1 7 2 Appendix M Modbus Interoperability 260 ...
Page 289: ...6 F 2 T 0 1 7 2 Appendix N IEC60870 5 103 Interoperability 290 ...
Page 296: ...6 F 2 T 0 1 7 2 Appendix O PLC Default setting 297 ...
Page 298: ...6 F 2 T 0 1 7 2 Appendix P Inverse Time Characteristics 299 ...
Page 304: ...6 F 2 T 0 1 7 2 Appendix Q IEC61850 Interoperability 305 ...