Rtd-Boxes For Overload Detection; Functional Description; Setting Notes; Settings - Siemens SIPROTEC 4 7UT6 Series Manual

2.10

RTD-Boxes for Overload Detection

For thermal overload protection, taking into consideration the ambient or coolant temperature as well as the
overload protection with hot-spot calculation and relative ageing rate determination, the coolant temperature
in the protected object or the temperature of the hottest spot of the winding (e.g. of a transformer) is
required. At least one resistance temperature detector (RTD) must be installed at the hot-spot location which
informs the device about this temperature via an RTD box 7XV5662-xAD. One RTD box is able to process up to
6 RTDs. One or two RTD boxes 7XV5662-xAD can be connected to the device.

Functional Description

2.10.1
One RTD box 7XV5662-xAD can be used for up to 6 measuring points (RTDs) in the protected object, e.g. in
the transformer tank. The RTD box detects the coolant temperature of each measuring point from the resist-
ance value of the temperature detectors (Pt 100, Ni 100 or Ni 120) connected with a two- or three-wire line
and converts it to a digital value. The digital values are output at the serial interface RS485.
One or two RTD boxes can be connected to the service interface of the 7UT6x. Thus, up to 6 or 12 measuring
points (RTDs) can be processed. For each temperature detector, characteristic data as well as alarm (stage 1)
and trip (stage 2) can be set.
The RTD box also acquires thresholds of each single measuring point. The information is then passed on via an
output relay. For further information, refer to the instruction manual of the RTD box.

Setting Notes

2.10.2
General
Set the type of temperature detector for RTD 1 (temperature sensor for measuring point 1) at address 9011
RTD 1 TYPE. You can choose between Pt 100 Ω, Ni 120 Ω and Ni 100 Ω. If no temperature detector is
available for RTD 1, set RTD 1 TYPE = Not connected. This parameter can only be set with DIGSI under
Additional Settings.
Address 9012 RTD 1 LOCATION informs the device regarding the mounting location of RTD 1. You can
choose between Oil, Ambient, Winding, Bearing and Other. This parameter can only be set with DIGSI
under Additional Settings.
Furthermore, in the 7UT6x an alarm temperature (stage 1) and a tripping temperature (stage 2) can be set.
Depending on the temperature unit selected in the power system data in address 276 TEMP. UNIT, the alarm
temperature can be selected in degree Celsius (°C) in address 9013 RTD 1 STAGE 1 or in degree Fahrenheit
(°F) in address 9014 RTD 1 STAGE 1. The trip temperature expressed in Celsius (°C) is set in address 9015
RTD 1 STAGE 2, and under address 9016 RTD 1 STAGE 2 it can be set in degree Fahrenheit (°F) .
Temperature Detectors
The setting options and addresses of all connected temperature detectors for the first and the second RTD-box
are listed in the following parameter overview.

Settings

2.10.3
Addresses which have an appended "A" can only be changed with DIGSI, under "Additional Settings".
Addr. Parameter
9011A RTD 1 TYPE
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Setting Options
Not connected
Pt 100 Ω
Ni 120 Ω
Ni 100 Ω
2.10 RTD-Boxes for Overload Detection
Default Setting Comments
Pt 100 Ω RTD 1: Type
Functions
211