ABB REC670 Applications Manual page 521

1MRK 511 401-UEN A
Bay control REC670 2.2 IEC
Application manual
• Standard: Winding time constant is taken from the IEEE or IEC standard as
selected for the temperature calculations.
• User defined: Winding time constant is provided by the user through setting.
The value may be given by the transformer manufacturer.
• Calculated: Winding time constant is calculated by the function based on the
transformer parameters given by the user.
WdgTimeConst1: This setting is used to get the winding time constant for winding
1. This is used when the WdgTmConstMode setting is selected as User defined.
WdgTimeConst2: This setting is used to get the winding time constant for winding
2. This is used when the WdgTmConstMode setting is selected as User defined.
WdgTimeConst3: This setting is used to get the winding time constant for winding
3. This is used when the WdgTmConstMode setting is selected as User defined.
The winding time constant is likely to be in the order of 5 to 20 minutes.
ConductorType: This setting is used to select the winding material between copper
and aluminum. This setting is useful when setting WdgTmConstMode is selected
for calculation. This setting has two options:
• Copper: Winding material is selected as copper.
• Aluminum: Winding material is selected as aluminum.
Winding to oil temperature gradient differs from winding to winding depending on
current density in the winding, physical dimensions, cooling system etc., This
value can be between 10 to 20 ̊ C for both distribution and power transformers. For
low current density winding it can be 10 ̊ C and for high current density winding it
can be 20 ̊ C. The settings given below are also used for the calculation of winding
time constant.
WdgToOilGrad1: Winding to oil temperature gradient for the winding 1 at rated
load.
WdgToOilGrad2: Winding to oil temperature gradient for the winding 2 at rated
load.
WdgToOilGrad3: Winding to oil temperature gradient for the winding 3 at rated
load.
CuLossW1: This setting is used to set the winding loss at rated load for the winding
1.
CuLossW2: This setting is used to set the winding loss at rated load for the winding
2.
CuLossW3: This setting is used to set the winding loss at rated load for the winding
3.
MassW1: This setting is used to set the mass of the winding 1.
Section 17
Monitoring
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