Micom P341 - Thermal Overload; Earth Fault

P341/EN AD/F43 Update Documentation
(AD) -20 MiCOM P341
Curve 5 IEEE moderately inverse
Curve 6 IEEE very inverse
Curve 7 IEEE extremely inverse
Curve 8 US inverse
Curve 9 US short time inverse
Amercian Curves
Curve 5
100.010.01.0
Current (Multiples of Is)
0.1
1
10
100
Operating Time (s)
Curve 6
Curve 9
Curve 7
Curve 8
P2137ENa
NPS Overcurrent
2>1 Status: Disabled/Enabled
2>1 Direction:
Non-Directional
Directional Fwd
Directional Rev
2> Current Set: 0.08…4.00n
2> Time Delay: 0.00…100.00s
2>2/3/4 as for 2>1
2> VTS Block:
Bit 0 = VTS Blocks 2>1
Bit 1 = VTS Blocks 2>2
Bit 2 = VTS Blocks 2>3
Bit 3 = VTS Blocks 2>4
Bits 4, 5, 6 & 7 are not used
Binary function link string, selecting which
NPS overcurrent elements (stages 1 to 4)
will be blocked if VTS detection of fuse
failure occurs.
2> V2pol Set:
0.5…25.0 (100V 120V)
2…100V (380/480V)
2> Char Angle: -95…+95
Thermal Overload
Thermal: Disabled/Enabled
Thermal I>: 0.50…2.50 In
Thermal Alarm: 20..100%
T-heating: 1…200 minutes
T-cooling: 1…200 minutes
M Factor: 0…10
The thermal time characteristic is given by:
t =  loge (eq
2
- P
2
)/(eq
2
- (Thermal >)
2
)
t = . loge ((K
2
-A
2
)/(K
2
-1))
Where:
K = eq/Thermal >
A = P/Thermal >
t = Time to trip, following application of the
overload current, 
 = Heating time constant of the protected
plant

eq
= Equivalent current
Thermal > = Relay setting current

P
= Steady state pre-load current
before application of the
overload

eq
= (
1
2
+ M
2
2
)
1 = Positive sequence current
2 = Negative sequence current
M = A user settable constant
proportional to the thermal
capacity of the machine
Earth Fault
IN1>1 Function:
Disabled
DT
IEC S Inverse
IEC V Inverse
IEC E Inverse
UK LT Inverse
RI
IEEE M Inverse
IEEE V Inverse
IEEE E Inverse
US Inverse
US ST Inverse
IDG
IN1>1 Directional
Non-Directional
Directional Fwd
Directional Rev
IN1>1 Current Set: 0.08…4.00 In
IN1>1 IDG Is: 1.0…4.0 In
IN1>1 Time Delay: 0.00…200.00s
IN1>1 TMS: 0.025…1.200
IN1>1 Time Dial: 0.01…100.00
IN1>1 K(RI): 0.10….10.00
IN1>1 IDG Time: 1.00...2.00
IN1>1 Reset Char.: DT/Inverse
IN1>1 tRESET: 0.00…100.00s
IN1>2 as IN>1
IN1>3 Status:
Disabled
Enabled
IN1>3 Directional: