Set Points For Measured Values; Description - Siemens siprotec SJ62 User Manual

2 Functions

2.23.7 Set Points for Measured Values

Applications

2.23.7.1 Description

Limit Value Moni-
toring
339
SIPROTEC devices allow limit values (set points) to be set for some measured and
metered values. If, during operation, a value reaches one of these limit values, the
device generates an alarm which is indicated as an operational message. This can be
configured to LEDs and/or binary outputs, transferred via the ports and interconnected
in DIGSI CFC. In addition you can use DIGSI CFC to configure limit values for further
measured and metered values and allocate these via the DIGSI device matrix. In con-
trast to the actual protection functions the limit value monitoring function operates in
the background; therefore it may not pick up if measured values are changed sponta-
neously in the event of a fault and if protection functions are picked up. Furthermore,
since a message is only issued when the limit value is repeatedly exceeded, the limit
value monitoring functions do not react as fast as protection functions trip signals.
• This monitoring program works with multiple measurement repetitions and lower
priority than the protection functions. For that reason, in the event of a fault it may
not respond to fast measured value changes before protection functions are started
and tripped. This monitoring program is not suitable for blocking protection func-
tions.
Ex works, the following individual limit value levels are configured:
• IAdmd>: Exceeding a preset maximum average value in Phase A.
• IBdmd>: Exceeding a preset maximum average value in Phase B.
• ICdmd>: Exceeding a preset maximum average value in Phase C.
• I1dmd>: Exceeding a preset maximum average positive sequence current.
• |Pdmd|> : Exceeding a preset maximum average active power.
• |Qdmd|>: Exceeding a preset maximum average reactive power.
• Sdmd>: Exceeding a preset maximum average value of reactive power.
• Temp>: Exceeding a preset temperature (if measuring transducer available).
• Pressure<: Exceeding a preset pressure (if measuring transducer available).
• IL<: Falling below a preset current in any phase.
• |cosϕ |<: Falling below a preset power factor.
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015