ABB Relion 670 Series Technical Reference Manual page 462

Section 7
Current protection
7.7.6
7.8
456
Technical data
Table 218: LFPTTR/LCPTTR (26) technical data
Function
Reference current
Reference temperature
Trip time:
é
ê
2 - 2
I I
ê
t
=
p
t ln
ê -
T
2 - 2 - Trip
I I
ê
p
ë T
ref
EQUATION13000039 V2 EN
T = set trip temperature
Trip
T = ambient temperature
Amb
T = temperature rise above ambient at I
ref
I = reference load current
ref
I = actual measured current
I = load current before overload occurs
p
Alarm temperature
Trip temperature
Reset level temperature
Breaker failure protection CCRBRF (50BF)
Function description
Breaker failure protection
Range or value
(0-400)% of
(0-400)°C, (0 - 600)°F
Time constant t = (1–1000) minutes
ù
ú
ú
ú
T
Amb × 2
I
ú
ref
û
(Equation 96)
ref
(0-400)°F, (0-200)°C
(0-400)°C, (0-600)°F
(0-400)°C, (0-600)°F
IEC 61850
identification
CCRBRF
1MRK505222-UUS C
Accuracy
IBase
± 1.0% of I
± 2°F, ±2°F
IEC 60255-8, ±5.0%
or ±200 ms
whichever is greater
± 2.0% of heat
content trip
± 2.0% of heat
content trip
± 2.0% of heat
content trip
IEC 60617 ANSI/IEEE C37.2
identification device number
50BF
3I>BF
SYMBOL-U V1 EN
Technical reference manual
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