Tan delta is the insulation power factor & is equal to the ratio of power dissipated in the insulation in watts to the product of effective voltage & current in volt ampere when tested under sinusoidal voltage.
2. TAN DELTA(INSULATION DISSIPATION FACTOR)
Tan delta is the insulation power factor & is equal to
the ratio of power dissipated in the insulation in
watts to the product of effective voltage & current in
volt ampere when tested under sinusoidal voltage.
3. PROCEDURE
All windings immersed in insulating liquid.
All windings shortcircuited using bare braided
jumper such that jumper shall not be allowed to sag.
All bushings in place.
Temperature of winding & insulation liquid near to
the reference temperature(27 degree).
All bushings cleaned properly.
Transformer earthed properly.
4. Neutral,star point of 3 phase winding connected to
other bushing of that winding by means of short
jumper.
Tan delta is then tested between below
combinations,
a. HV to EARTH
b. LV to EARTH
c. HV to LV.
5. TEST SETUP
TRANSFORMER SPECIFICATONS
RATING-100 MVA
VOLTAGE CLASS-33KV/220KV
Yyn-0
COOLING-OFAF
INSTRUMENT MAKE-OMICRON
APPLIED VOLTAGE-10KV