Signals - ABB RELION 620 Series Technical Manual

Section 4
Protection functions
4.5.2.6
386
Table 318: Conversion table between one and two time constants
Short time constant (min) Long time constant (min) Weighting factor p
Single time constant (min)
10 1.1
15 1.6
20 2.1
25 2.6
30 3.1
35 3.6
40 4.1
45 4.8
50 5.1
55 5.6
60 6.1
65 6.7
70 7.2
75 7.8
The default Max temperature setting is 105°C. This value is chosen since even though the
IEC 60076-7 standard recommends 98°C as the maximum allowable temperature in long-
time loading, the standard also states that a transformer can withstand the emergency
loading for weeks or even months, which may produce the winding temperature of 140°C.
Therefore, 105°C is a safe maximum temperature value for a transformer if the Max
temperature setting value is not given by the transformer manufacturer.

Signals

Table 319: 49T Input signals
Name Type
I_A SIGNAL
I_B SIGNAL
I_C SIGNAL
BLOCK BOOLEAN
TEMP_AMB FLOAT32
17
25
33
41
49
58
60
75
82
90
98
107
115
124
Default Description
0 Phase A current
0 Phase B current
0 Phase C current
0=False Block signal for the function
0 The ambient temperature used in the calculation
1MAC504801-IB E
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
620 series ANSI
Technical Manual