NR Electric PCS-9611, Instruction Manual

Page: 54 / 300

3 Operation Theory
PCS-9611 Feeder Relay
3-18
Date: 2014-04-08
[49.Alm]
Thermal
Accumulator
CLR
&
Imax_rms > [49.K_Trp]×[49.Ib_Set]
[49.En1]
[49.En_Trp]
[49.Clr]
[49.Blk]
&
Imax_rms > [49.K_Alm]×[49.Ib_Set]
[49.En_Alm]
[49.Clr]
[49.Blk]
[49.Op]
[49.St]
Thermal
Accumulator
CLR
Figure 3.4-2 Logic diagram of the thermal overload protection
Where:
“Imax_rms” is the maximum RMS phase current;
[49.K_Trp] is the factor setting of the thermal overload protection;
[49.Ib_Set] is the reference current setting of the ther mal overload protection;
[49.K_Alm] is the factor setting of the thermal overload alarm element;
[49.En_Trp] is the logic setting of the thermal overload protection;
[49.En_Alm] is the logic setting of the thermal overload alarm element;
[49.En1] is the binary signal for enabling the thermal overload protection;
[49.Blk] is the binary signal for blocking the thermal overload protection;
[49.Clr] is the binary signal for clearing the thermal accumulation.
3.4.2 Thermal Overload Protection Settings
All the settings of the thermal overload protection are listed in the following table. For the
information about the common explanation of the settings, see Section 7.3 .
No. Menu text Explanation Range Step
1 49.Ib_Set
The reference current s etting of the thermal
overload protection
0.05In~3.0In 0.001A
2 49.Tau
The time constant setting of the thermal overload
protection
10~6000s 0.001s
3 49.C_Disspt
The thermal dissipation constant s etting of the
thermal overload protection
0.2~5.0 0.001
4 49.K_Trp
The factor setting of the thermal overload
protection which is associated to the thermal state
formula
1.0~3.0 0.001
5 49.K_Alm
The factor setting of the thermal overload alarm
element which is associated to the thermal state
formula
1.0~3.0 0.001