Siemens Siprotec 7UM611 User Manual

2.8 Inverse-Time Overcurrent Protection (ANSI 51V)
57
7UM61 Manual
C53000-G1176-C127-3
The current value is set at address 1402 Ip. The setting is mainly determined by the
maximum operating current. Pickup due to overload should never occur, since the
device in this operating mode operates as fault protection with correspondingly short
tripping times and not as overload protection.
The corresponding time multiplier for configuration of IEC characteristics (address
114 O/C PROT. Ip = with IEC) is accessible under address 1403 T Ip.
The corresponding time multiplier for configuration of ANSI characteristics (address
114 O/C PROT. Ip= with ANSI) is accessible under address 1404 TIME DIAL:
TD.
The time multipliers must be coordinated with the network grading plan.
The time multipliers can also be set to ∞. After pickup the element will then not trip.
Pickup, however, will be signaled. If the Ip stage is not required, on configuration of
the protection function (Section 2.2) address 114 O/C PROT. Ip is set to Disabled
or this function switched under 1401 O/C Ip = OFF.
The address 1408 serves to predefine the U< pick-up value for the undervoltage trip
of the Ip pickup value for voltage-controlled inverse overcurrent time protection/AMZ
(parameter 1407 VOLT. INFLUENCE = Volt. controll.). The parameter is set
to a value just below the lowest phase-to-phase voltage admissible during operation,
e.g. from 75 to 80 V. In this context, the same rules apply as for the undervoltage seal-
in of the definite overcurrent time protection (see also subsection 2.6.2).
If at address 1407 VOLT. INFLUENCE is set to without or Volt. restraint, the
parameter 1408 has no function.
2.8.3 Settings
The table indicates region-specific presettings. Column C (configuration) indicates the
corresponding secondary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
1401 O/C Ip OFF
ON
Block relay
OFF Inverse O/C Time Protec-
tion Ip
1402 Ip 1A 0.10 .. 4.00 A 1.00 A Ip Pickup
5A 0.50 .. 20.00 A 5.00 A
1403 T Ip 0.05 .. 3.20 sec; ∞ 0.50 sec T Ip Time Dial
1404 TIME DIAL: TD 0.50 .. 15.00 ; ∞ 5.00 TIME DIAL: TD
1405 IEC CURVE Normal Inverse
Very Inverse
Extremely Inv.
Normal Inverse IEC Curve
1406 ANSI CURVE Very Inverse
Inverse
Moderately Inv.
Extremely Inv.
Definite Inv.
Very Inverse ANSI Curve
www . ElectricalPartManuals . com

Siemens Siprotec 7UM611 Specifications

General

Brand	Siemens
Model	Siprotec 7UM611
Category	Relays
Language	English