ABB RES670 Product Manual page 35

Phasor measurement unit RES670 ANSI
Customized
Product version: 1.2
Table 25. Sensitive directional residual overcurrent and power protection SDEPSDE (67N) , continued
Function
Reset time, non-directional
residual over current
Operate time, pickup function
Reset time, pickup function
Table 26. Thermal overload protection, one time constant LFPTTR/LCPTTR (26)
Function
Reference current
Reference temperature
Trip time:
é
ê
2 -
I I
ê
t
= p
t ln
ê -
T
2 - 2 - Trip
I I
ê
p
T
ë
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
ABB
Range or value
60 ms typically at 2 to 0 x I
150 ms typically at 0 to 2 x I
50 ms typically at 2 to 0 x I
Range or value
(0-400)% of
(0-400)°C, (0 - 600)°F
Time constant t = (1–1000) minutes
ù
ú
2
ú
ú
T
Amb × 2
I
ú
ref
û
(Equation 1)
ref
(0-400)°F, (0-200)°C
(0-400)°C, (0-600)°F
(0-400)°C, (0-600)°F
set
set
set
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
1MRK511254-BUS B
Accuracy
-
-
-
n
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