Table 51. Thermal overload protection, two time constants (T2PTTR)
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: f
n
±2 Hz
Current measurement: ±1.5% of the set value or ±0.002 x I
n
(at
currents in the range of 0.01...4.00 x I
n
)
Operate time accuracy
1)
±2.0% of the theoretical value or ±0.50 s
1)
Overload current > 1.2 x Operate level temperature
Table 52. Thermal overload for protection, two time constants (T2PTTR) main settings
Parameter
Function
Value (Range)
Step
Temperature rise
T2PTTR
0.0...200.0
o
C
0.1
Max temperature
T2PTTR
0.0...200.0
o
C
0.1
Operate temperature
T2PTTR
80.0...120.0 %
0.1
Weighting factor p
T2PTTR
0.00...1.00
0.01
Short time constant
T2PTTR
6...60000 s
1
Current reference
T2PTTR
0.05...4.00 x I
n
0.01
Operation
T2PTTR
Off
On
-
Table 53. Phase undercurrent protection (PHPTUC)
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: fn ±2 Hz
±1.5% of the set value or ±0.002 x In
Start time
Typical <55 ms
Reset time
<40 ms
Reset ratio
Typical 1.04
Retardation time
<35 ms
Operate time accuracy in definite time mode
mode ±1.0% of the set value or ±20 ms
Table 54. Phase undercurrent protection (PHPTUC) main settings
Parameter
Function
Value (Range)
Step
Start value
PHPTUC
0.01...1.00 xIn
0.01
Operate delay time
PHPTUC
50...200000 ms
10
Current block value
PHPTUC
0.00...0.50 xIn
0.01
Transformer Protection and Control
1MRS757846 A
RET620
Product version: 2.0
36
ABB
