Qualitrol 509ITM Series, Manual

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Advanced Winding Rise Parameters
This section of the Advanced CT Temperature Scaling Setup window includes the fields
described below.
Cooling Relay
(3 fields) Allows you to input the relay number that controls the cooling system for
each cooling stage.
Example: Relay 2 controls fan bank 1, Relay 3 controls fan bank 2, and
Relay 4 energizes the oil pump.
Current
Factor
(4 fields) Allows you to enter the measured current that the clamp-on CT will sense
on the secondary side of the instrumentation or metering CT for each
current stage at nominal loading.
Example: A 30/40/50 MVA Single-Phase Transformer at 132 - 32 kV
with a CT 2000/5 A at its secondary side, which is the winding to be
configured.
•
In ONAN mode: 30 MVA / 32 kV * 5/2000 = X
•
In first cooling mode: 40 MVA / 32 kV * 5/2000 = X
•
In second cooling mode: 50 MVA / 32 kV * 5/2000 = X
Note:
For a three- phase transformer application, divide the current by
the square root of three.
Winding Rise
Temperature
(4 fields) Allows you to set the temperature gradients (delta T) for each winding at
each cooling stage. This value is the winding temperature rise over the
specified liquid temperature for that given current factor. The liquid
temperature will typically be the top oil temperature measurement. The
509ITM accepts a maximum of 70° C for the temperature gradient.
You can calculate the winding rise value from data in the transformer
heat run report. The winding rise gradient is the winding rise temperature
over ambient minus the oil rise temperature over ambient.