ABB REC670 Applications Manual page 522

Section 17
Monitoring
516
MassW2: This setting is used to set the mass of the winding 2.
MassW3: This setting is used to set the mass of the winding 3.
Loss ratios at different tap positions are required for the calculation of top oil
temperature, especially when the transformer is using online tap changer. This loss
ratio is the ratio between load losses to no-load loss. It may vary from 6 -7 for
distribution transformer and 4-8 for power transformer. Normally it varies from 3
to 11. The function has the following settings related to loss ratio calculation.
RLRated: This setting is used to set the ratio of load losses to no-load loss at
principal tapping position.
RLHighRated: This setting is used to set the ratio of load losses to no-load loss at
principal tapping +1 position.
RLMaxTap: This setting is used to set the ratio of load losses to no-load loss at
maximum tap position where maximum voltage is possible.
RLMinTap: This setting is used to set the ratio of load losses to no-load loss at
minimum tap position where minimum voltage is possible.
RatedVoltTap: This setting is used to set the position number of tap changer at rated
voltage.
HighVoltTap: This setting is used to set the position number of tap changer at
possible maximum voltage.
LowVoltTap: This setting is used to set the position number of tap changer at
possible minimum voltage.
The following settings are required to perform the calculation of top oil
temperature using monthly model of ambient temperature when AMBVALID is
low:
JanAmbTmp: This setting is used to set the January month average ambient
temperature.
FebAmbTmp: This setting is used to set the February month average ambient
temperature.
MarchAmbTmp: This setting is used to set the March month average ambient
temperature.
AprilAmbTmp: This setting is used to set the April month average ambient
temperature.
MayAmbTmp: This setting is used to set the May month average ambient
temperature.
JuneAmbTmp: This setting is used to set the June month average ambient
temperature.
1MRK 511 401-UEN A
GUID-8A9D8886-8EE5-4B02-80B8-BDDA95164BFF v1
GUID-E9EC48CC-08D6-498E-BFB7-6F40AD9436A7 v1
Bay control REC670 2.2 IEC
Application manual