7.7.6 Technical data
Table 218: LFPTTR/LCPTTR (26) technical data
Function Range or value Accuracy
Reference current (0-400)% of
IBase
± 1.0% of I
n
Reference temperature (0-400)°C, (0 - 600)°F ± 2°F, ±2°F
Trip time:
2 2
2 2 2
ln
p
Trip Amb
p ref
ref
I I
t
T T
I I I
T
t
-
=
-
- - ×
é ù
ê ú
ê ú
ê ú
ê ú
ë û
EQUATION13000039 V2 EN (Equation 96)
T
Trip
= set trip temperature
T
Amb
= ambient temperature
T
ref
= temperature rise above ambient at I
ref
I
ref
= reference load current
I = actual measured current
I
p
= load current before overload occurs
Time constant t = (1–1000) minutes IEC 60255-8, ±5.0%
or ±200 ms
whichever is greater
Alarm temperature (0-400)°F, (0-200)°C ± 2.0% of heat
content trip
Trip temperature (0-400)°C, (0-600)°F ± 2.0% of heat
content trip
Reset level temperature (0-400)°C, (0-600)°F ± 2.0% of heat
content trip
7.8 Breaker failure protection CCRBRF (50BF)
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Breaker failure protection CCRBRF
SYMBOL-U V1 EN
50BF
Section 7 1MRK505222-UUS C
Current protection
456
Technical reference manual