Table 33. Thermal overload protection, two time constants TRPTTR
Function
Range or value
Accuracy
Base current 1 and 2
(30–250)% of
IBase
± 1.0% of I
r
Operate time:
2
2
2
2
p
ref
I
I
t
ln
I
I
t
æ
ö
-
ç
÷
= ×
ç
÷
-
è
ø
EQUATION1356 V2 EN
(Equation 1)
I = actual measured current
Ip = load current before overload
occurs
Iref = reference load current
I
p
= load current before overload
occurs
Time constant τ = (1–500)
minutes
IEC 60255–8, ±5% + 200 ms
Alarm level 1 and 2
(50–99)% of heat content trip
value
± 2.0% of heat content trip
Operate current
(50–250)% of
IBase
± 1.0% of I
r
Reset level temperature
(10–95)% of heat content trip
± 2.0% of heat content trip
Table 34. Breaker failure protection, 3-phase activation and output CCRBRF
Function
Range or value
Accuracy
Operate phase current
(5-200)% of
lBase
±
1.0% of I
r
at I
£
I
r
±
1.0% of I at I > I
r
Reset ratio, phase current
> 95%
-
Operate residual current
(2-200)% of
lBase
±
1.0% of I
r
at I
£
I
r
±
1.0% of I at I > I
r
Reset ratio, residual current
> 95%
-
Phase current level for blocking of contact function
(5-200)% of
lBase
±
1.0% of I
r
at I
£
I
r
±
1.0% of I at I > I
r
Reset ratio
> 95%
-
Timers
(0.000-60.000) s
±
0.5%
±
10 ms
Operate time for current detection
20 ms typically
-
Reset time for current detection
10 ms maximum
-
Table 35. Pole discordance protection CCRPLD
Function
Range or value
Accuracy
Operate value, current
asymmetry level
(0-100) %
± 1.0% of I
r
Reset ratio
>95%
-
Time delay
(0.000-60.000) s
± 0.5% ± 25 ms
Transformer protection RET650
1MRK 504 137-BEN B
Product version: 1.3
44
ABB
