Allen-Bradley 857 User Manual

Rockwell Automation Publication 857-QS001B-EN-P - April 2017 9
Overview Chapter 1
48 I
st
> Stall protection Only available when
application mode is
motor protection.
49 T> Thermal overload protection
50ARC ArcI> Optional arc fault-protection
50BF CBFP Circuit-breaker failure protection
50N/51N
50G/51G
50GS/51GS
I
0
>
I
0
>>
I
0
>>>
I
0
>>>>
Earth-fault protection External connection
method and protective
settings define
protection type.
50NARC ArcI
01
>
ArcI
02
>
Optional earth-fault protection
50NC/51INC I
0
CAP Capacitor-bank unbalance protection
50/51 I>
I>>
I>>>
Overcurrent protection
59 U>
U>>
U>>>
Overvoltage protection
59N U
0
>
U
0
>>
Residual voltage protection
66 N> Frequent start protection Only available when
application mode is
motor protection.
67 I
φ
>
I
φ
>>
I
φ
>>>
I
φ
>>>>
Directional overcurrent protection
67N I
0
φ
>
I
0
φ
>>
Directional earth-fault protection
67NI I
Oint
> Directional transient intermittent earth-fault
protection
68F2 U
f2
> Magnetizing In Rush
68F5 U
f5
> Transformer over excitation, 2nd harmonic
81 f><
f>><<
Frequency protection, 5th harmonic
81L f<
f<<
Underfrequency protection
81R df/dt Rate of change of frequency (ROCOF) protection
86 Lockout All protective elements
can be set for lockout
control.
99 Prg1…8 Programmable stages
Table 1 - List of Protection Functions (continued)
IEEE/ ANSI Code IEC Symbol Function Name Note

Allen-Bradley 857 Specifications

General

Brand	Allen-Bradley
Model	857
Category	Protection Device
Language	English