Settings - Siemens Siprotec 7UM611 Manual

specifications. In this context, frequency decrease protection ensures the power sta-
tion's own demand by disconnecting it from the power system on time. The turbo reg-
ulator then regulates the machine set to nominal speed so that the station's own re-
quirements can be continuously provided at rated frequency.
Under the assumption that apparent power is reduced to the same degree, turbine-
driven generators can, as a rule, be continuously operated down to 95 % of nominal
frequency. However, for inductive consumers, the frequency reduction not only means
greater current consumption but also endangers stable operation. For this reason,
only a short-time frequency reduction down to about 48 Hz (for f
(for f
A frequency increase can, for example, occur due to a load shedding or malfunction
of the speed regulation (e.g. in an island network). In this way, the frequency increase
protection can, for example, be used as overspeed protection.
Setting example:
The time delays T f1 to T f4 entered at addresses 4204, 4207, 4210 and 4213)
Time Delays
allow the frequency stages to be graded. The set times are additional time delays not
including the operating times (measuring time, drop-out time) of the protective func-
tion.
Address 4215 Umin is used to set the minimum voltage which if undershot, frequency
Minimum Voltage
protection is blocked. A value of approx. 65 % U
value is based on phase-to-phase voltages. The minimum voltage threshold can be
deactivated by setting this address to 0.

2.17.3 Settings

Addr. Parameter
4201 O/U FREQUENCY
4202 f1 PICKUP
4203 f1 PICKUP
4204 T f1
4205 f2 PICKUP
4206 f2 PICKUP
4207 T f2
4208 f3 PICKUP
7UM61 Manual
C53000-G1176-C127-3
= 60 Hz) is permissible.
N
Stage Cause
f1 Disconnection
from the network
f2 Shutdown
f3 Warning
f4 Alarm or tripping 52.00 Hz
Setting Options
OFF
ON
Block relay
40.00 .. 65.00 Hz
40.00 .. 65.00 Hz
0.00 .. 600.00 sec
40.00 .. 65.00 Hz
40.00 .. 65.00 Hz
0.00 .. 100.00 sec
40.00 .. 65.00 Hz
2.17 Frequency Protection (ANSI 81)
Settings
for f = 50 Hz for f = 60 Hz
N N
48.00 Hz 58.00 Hz
47.00 Hz 57.00 Hz
49.50 Hz 59.50 Hz
62.00 Hz
is recommended. The parameter
N
Default Setting
OFF Over / Under Frequency Protec-
tion
48.00 Hz f1 Pickup
58.00 Hz f1 Pickup
1.00 sec T f1 Time Delay
47.00 Hz f2 Pickup
57.00 Hz f2 Pickup
6.00 sec T f2 Time Delay
49.50 Hz f3 Pickup
= 50 Hz) or 58 Hz
N
Delay
1.00 sec
6.00 sec
20.00 sec
10.00 sec
Comments
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