ABB REC670 Applications Manual page 519

1MRK 511 401-UEN A
Bay control REC670 2.2 IEC
Application manual
• Average: The average of all phase currents of winding is considered for
calculation.
• Maximum: The maximum current out of the all phase currents is considered
for calculation.
TempeUnitMode: This setting is used to select the temperature unit to be used for
the function interface. The options are:
• °F: The temperature unit will be selected as °F. Since all calculation formulae
needs temperature values in °C, the temperature inputs are converted into °C
for calculation. Once the calculations are done, the outputs in °C are converted
into °F.
• °C: The temperature unit will be selected as °C. All temperature inputs will be
taken as they are and the output is given in °C.
LOLSPTR can work with (n-1) winding CT availability, that is, if the given
transformer has three windings and it has CTs only in two windings, then the
function will calculate the missing winding current based on voltage transformation
ratio. Following settings are required to calculate the winding current with
available CT input:
AvailableCT: Availability of CT connection can be set by this setting. The options
are:
• Winding 1: Only winding 1 CT is available. This option can be selected when
two winding transformer is considered.
• Winding 2: Only winding 2 CT is available. This option can be selected when
two winding transformer is considered.
• Winding 1&2: Only winding 1 and winding 2 CTs are available. This option
can be selected when three winding transformer is considered.
• Winding 1&3: Only winding 1 and winding 3 CTs are available. This option
can be selected when three winding transformer is considered.
• Winding 2&3: Only winding 2 and winding 3 CTs are available. This option
can be selected when three winding transformer is considered.
• All windings: All windings CTs are available. This option can be selected for
both two and three winding transformer.
RatedVoltW1: This setting is used to set the rated voltage of winding 1 in kV.
RatedVoltW2: This setting is used to set the rated voltage of winding 2 in kV.
RatedVoltW3: This setting is used to set the rated voltage of winding 3 in kV.
UPerTap: This setting is used to set the voltage increment/decrement between two
successive tap positions (ΔV) in kV.
Time required for the top oil temperature in relation to ambient temperature to
reach its ultimate value is a function of the thermal oil time constant. The function
has the following settings related to oil time constant.
Section 17
Monitoring
GUID-4D6F8802-AFCC-4277-8844-A87A98A5F2C8 v1
GUID-2D78A349-4A55-441A-BEC6-A590A1742AE2 v1
513