Setting Guidelines - ABB REC670 Applications Manual

1MRK 511 401-UEN A
17.11.2
Bay control REC670 2.2 IEC
Application manual
and oxygen contributions to insulation deterioration can be minimized, leaving
insulation temperature as the controlling parameter.
Temperature distribution is not uniform in transformers, the part that is operating at
the highest temperature normally undergoes the greatest deterioration. Therefore, in
aging studies it is usual to consider the aging effects produced by the highest
(hottest-spot) temperature. Since many factors influences the cumulative effect of
temperature over time which causes transformer insulation deterioration, it is
difficult to predict the useful life of the insulation in a transformer with great
degree of accuracy. However, this function will help in reducing the accelerated
aging of power transformers during overload conditions and thus maximize the
transformer operating life.

Setting guidelines

The parameters for the estimation of transformer insulation life function LOLSPTR
are set via the local HMI or PCM600.
Minimum information about the transformer parameters which are required to
decide the transformer insulation life are:
1. Top oil temperature rise over ambient temperature at rated load
2. Average conductor temperature rise over ambient temperature at rated load
3. Winding hot spot temperature rise over ambient temperature
4. Load losses at rated load
5. No-Load (core) loss
6. Oil flow design (Directed or non-directed)
7. Weight of core and coil assembly
8. Weight of tank and fittings
9. Weight of oil in the tank and cooling equipment (excluding load tap changer,
oil expansion tanks)
For information about 1 to 5, the conditions (load, ambient temperature, tap, etc.)
under which the measurements are made should be known. In order to have more
precise calculations, load loss at rated and tap extremes or all possible tap
connection combinations are required.
Operation: Off or On.
TrafoRating: Rated transformer power in MVA.
TrafoType: This setting is used to set the number of phases in the transformer. The
options are:
• Three Phase Trafo: The function considers the given transformer as three
phase transformer.
• Single Phase Trafo: The function considers the given transformer as single
phase transformer.
Section 17
Monitoring
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