Siemens SIPROTEC 7UT613 series Manual page 228

2 Functions
Environment Tem-
perature Influence
in Thermal Replica
Alarm Stages with
Thermal Replica
Emergency Start
for Motors
Temperature Detec-
tor for Hot-spot Cal-
culation
228
If the environmental or coolant temperature must be taken into consideration in the
thermal replica, the device must be informed as to which of the temperature detectors
(RTD = Resistance Temperature Detector) is applicable. With RTD-box 7XV5662–
xAD up to 6 detectors are possible, with 2 boxes up to 12. In case of connection of one
RTD-box, under address 4210 TEMPSENSOR RTD the number of the applicable tem-
perature detector (1 to 6) must be set, in case of connection of two RTD-boxes under
address 4211 TEMPSENSOR RTD (1 to 12). Only such address is always available that
corresponds with the setting in accordance with the functional scope (section 2.1.3.1)
under address 191 RTD CONNECTION.
All calculations are performed with standardised quantities. The ambient temperature
must also be standardised. The temperature with nominal current of the protected
object is used as standardised quantity. Set this temperature under address 4212
TEMP. RISE I in °C or under address 4213 TEMP. RISE I in °F, depending on
which temperature unit was selected in accordance with section 2.1.4.
By setting a thermal alarm stage Θ ALARM (address 4204) an alarm can be released
before the tripping temperature is reached, so that a trip can be avoided by early load
reduction or by switching over. The percentage refers to the tripping temperature rise.
Note that the final temperature rise is proportional to the square of the current.
Example:
k-factor k = 1.1
Nominal current flow results in the following temperature rise:
The thermal warning stage should be set above temperature rise at nominal current
(82.6 %). A sensible setting value would be Θ ALARM = 90 %.
The current overload alarm setpoint I ALARM (address 4205) is referred to the rated
current of the side and should be set equal to or slightly below the permissible contin-
uous current k ·I . It can also be used instead of the thermal alarm stage. In this
N Obj
case, the thermal alarm stage is set to 100 % and is thus virtually ineffective.
The run-on time value to be entered at address 4208 T EMERGENCY must ensure that,
after an emergency start and dropout of the binary input , the trip command is blocked
until the thermal replica has fallen below the dropout threshold. This parameter can
only be set with DIGSI under Additional Settings.
The startup itself is only recognised if the startup current 4209 set in address I MOTOR
START is exceeded. Under each load and voltage condition during motor start, the
value must be overshot by the actual startup current. With short-time permissible over-
load the value must not be reached. This parameter can only be set with DIGSI under
Additional Settings. For other protected objects retain setting ∞. The emergency
start is thus disabled.
For the hot-spot calculation according to IEC 60354 the device must be informed on
the type of resistance temperature detectors (RTD) that will be used for measuring the
oil temperature, the one relevant for the hot-spot calculation and ageing determina-
tion. With a RTD-box 7XV5662x–xAD up to 6 detectors are possible, with 2 boxes up
to 12. On connection of one RTD-box set under address 4220 OIL-DET. RTD the
number of the relevant temperature detector (1 to 6), on connection of two RTD-boxes
under address 4221 OIL-DET. RTD (1 to 12). Only such address is always available
7UT613/63x Manual
C53000-G1176-C160-2