ABB CoreSense - Risks of Overloading a Transformer; SCADA Communication

CoreSense Hub option B65
Risks of overloading a transformer
There are risks associated with overloading a transformer beyond its nameplate values. These are covered in
the IEC 60076-7 standard and summarized the table below.
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Table 11 Factors increasing the risks of premature failure
Increased temperature The temperature of the windings, cleats, leads, insulation and oil will increase and can reach
unacceptable levels.
Increased leakage flux The leakage flux density outside the core increases, causing additional eddy current heating in
metallic parts linked by the leakage flux.
Increased gas and moisture As the temperature changes, the moisture and gas content in the insulation and in oil will
change.
Risks on accessories Bushings, tap-changers, cable-end connections and current transformers will also be exposed
to higher stresses which encroach upon design and application margins.
SCADA communication
For SCADA communication, CoreSense Hub uses the Modbus TCP protocol. This is similar to the standard
CoreSense but with specific register blocks for each external sensor linked to the CoreSense Hub. See
“Appendix C” on page C77 for more information on the standard Modbus parameters. Table 12 presents the
updated Modbus TCP interfaces between the CoreSense Hub to the SCADA.
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Table 12 Modbus TCP interfaces from CoreSense Hub to SCADA
Register Modbus
address
Parameter Function Data type Access
Status/Alarms
0
Not supported
0–10
Reserved for future use
Information
11–20 40011 Model number ASCII string R
21–30 40021 Serial number ASCII string R
31–40 40031 Software version ASCII string R
41–50 40041 System ID ASCII string R
51
40051
Manufacturing date
high byte = month
low byte = day
32-bit binary value
R
52 40052 Year R
Measurement
53 40053 Hydrogen (ppm) signed 16 bit binary number R
54
40054
Hydrogen RoC
(ppm/day)
may need scaling
signed 16 bit binary number
R
55
40055
RESERVED–Hydrogen RoC
(ppm/week)
return 0
signed 16 bit binary number
R
56
40056
RESERVED–Hydrogen RoC
(ppm/month)
return 0
signed 16 bit binary number
R
57
40057
Oil temperature (moisture)
(Celsius)
signed 16 bit binary number
R
58 40058 Moisture (aw) scaled by 100 signed 16 bit binary number R