Supply, erection, testing and commissioning of two nos. of 750KVA, 11kV/433V Generator auxiliary transfomers at MGHE power house, Karnataka power Corporation ltd, Jogfalls - 577435, Shimoga-dist., Karnataka

TECHNICAL PARTICULARS OF UNIT AUXILIARY TRANSFORMER

Sl. No. DETAILS

I 0_) Name of the manufacturer As per bidder

0_) Type of service (indoor/outdoor) Outdoor

0_) Applicable standards The Transformer shall comply with the latest edition of the standards and other relevant IEC standards

0_) No-load voltage ratio (guaranteed)

0_) Guaranteed continuous rating for the specified cooling, temperature rise over the ambient temperature (KVA)

0_) Rated voltage

0_) Rated frequency Hz

0_) No. of phases

0_) Current at rated voltage & on principal tap

0_) Vector group reference and symbol

0_) Guaranteed rated temperature rise above reference peak ambient temperature of air (deg. cen.)

a)Top oil by thermometer

b) of winding by resistance

0_) i. Guaranteed no-load losses at rated voltage & frequency at principal tap (KW) (without tolerance)

ii. No-load losses at the voltage corresponding to the highest tap (KW)

0_) No-load loss

a. At 90% rated voltage (KW)

b. At 100% rated voltage (KW)

c. At 110% rated voltage (KW)

0_) i. Guaranteed load losses at rated output, rated frequency and at 75 deg. cen. average winding temperature at principal tap (KW) (without tolerance)

ii. Load losses at rated output, rated frequency and at 75 deg. cen. average winding temperature at

0_) Guaranteed total losses at normal ratio, rated output, rated voltage and rated frequency and at 75 deg. cen. (KW) (without tolerance)

0_) Positive sequence impedance on rated MVA base at rated current & frequency at 75oC winding temperature at,

i) Principal tap(%)

ii) Highest tap(%)

iii) Lowest tap(%)

0_) Zero Sequence impedence at 750 C

i) Principal tap (%)

ii)Highest tap (%)

iii)Lowest tap (%)

0_) Resistance voltage drop at 750 C average winding temperature and rated full load expressed as percentage of rated MVA(All values to be referred to primary)

0_) Reactance voltage drop at 750 C and full load between windings expressed as % of rated voltage between H.V & L.V (%)

0_) Guaranteed impedance voltage at normal tap and at 75 deg.cen. average winding temperature expressed as percentage of rated voltage (%)

0_) Impedance per phase

i. Referred to H.V side (Ohms)

ii. Referred to L.V side (Ohms)

0_) Regulation at full load & 75 deg.cen. winding temperature expressed as a % of normal voltage

i) at unity P.F

ii) at 0.8 P.F(lagging)

0_) a) Efficiencies at normal ratio, rated voltage, rated frequency and 75 deg. cen. average winding temperature for the output at unity p.f. & 0.8 p.f. corresponding to

0_) i) Maximum efficiency(%)

ii)Load at which maximum efficiency occurs (% of full load)

0_) Permissible overloading

0_) Insulating & cooling medium

0_) External short circuit withstand capacity (MVA) & duration(secs.)

0_) Overflux withstand capability of the transformer corresponding to

ii) Factor 1.25

iii) Factor 1.4

0_) Ideal heating time or thermal time constant (Hours)

II Additional technical particulars

0_) Details of core

i) Type of core construction

ii) Type of joint between core limb & yoke

iii) Maximum flux density at rated voltage & frequency and at principal tap

a) Core (weber/sq.mtrs)

b) Yoke (weber/sq.mtrs)

iv)Max. flux density in iron at voltage and frequency 10% higher than normal (webers/sq.mtrs.)

v)Magnetising current at normal ratio & frequency

i) 90% of rated voltage

ii) 100% of rated voltage

iii) 110% of rated voltage

vi)power factor of magnetising current at normal voltage, ratio & frequency

vii) a)Material of core lamination and grade

b) Thickness of core lamination

c) Insulation between core lamination

d) Insulation of core bolts

e) Insulation of core bolt washers

f) Core bolt insulation withstand voltage for 1 minute(kV rms)

g) Are the core bolts grounded. If so how

h)Area of cross section of core lamination.

viii) a) Material of core clamping plate

b) Thickness of core clamping plate

c) Insulation of core clamping plate

ix) Describe location/method of core grounding

x) Details of oil ducts in core

xi) Exciting va/kg or w/kg of lamination material at

i) 15,000 gauss

ii) Rated induction (vide item iii(a))

iii) Induction as per item (iv)

0_) DETAILS OF WINDINGS:

i)Type of Winding

ii) Material of the winding conductor

iii) Maximum current density of windings and conductor area (at rated current)

a) Current density(A/cm2)

b) Conductor area(cm2)

iv) Type of joints in the windings

v) Resistance of (Approx)

i) HV winding(ohms/ph)

ii) LV winding(ohms/ph)

vi) Whether HV windings are interleaved

vii) Whether windings are preshrunk

viii) Whether adjustable coil clamps are provided for HV & LV windings

ix) Whether electrostatic shields are provided to obtain uniform voltage distribution in the HV windings

x)Insulation materials used for

xi) Insulation material used between

a) HV & LV winding

b) LV winding & core

xii) Type of axial coil supports

xiii) Type of radial coil supports

xiv) Maximum allowable torque on coil clamping bolts

xv) Minimum clearance to earth(cms)

xvi) Capacitance

a) HV winding to earth when LV earthed(pF)

b) LV winding to earth when HV earthed (pF)

c) Interwinding (pF)

xvii) Insulation strength of windings(1.2/50 microsec wave)

Impulse full wave (Withstand values)

i) HV winding (KVP)

ii) LV Winding (KVP)

Impulse chopped wave (Withstand values)

i) HV winding (KVP)

ii) LV Winding (KVP)

xviii)Separate source power frequency withstand voltage

i) HV Winding (KV rms)

ii) LV Winding (KV rms)

iii) Neutral end of LV (KV rms)

xix) Induced over voltage withstand voltage (kV rms)

i) Name of manufacturer

iii) Standards applicable

iv) Type of bushing

v) a) rated voltage class (kV)

b) rated current(Amps)

vi) Lightning impulse withstand voltage (KV peak) (1.2/50 microsecs)

vii) Power frequency withstand voltage(KV rms)

a) Wet for 1 minute(kv rms)

b) Dry for 1 minute(kV rms)

viii) Visible corona discharge voltage (KV rms)

ix) Partial discharge level

x) Creepage distance in air( mm)

xi) Creepage distance (protected)

xii)Recommended gap setting

xiii) Quantity of oil in bushing (kgs) & specification of oil used

xiv) Weight of assembled bushings in Kgs

xv) Minimum clearance height for removal of bushings(mm)

0_) MINIMUM CLEARANCE(mm)

i)In air (between phases & phase to ground)

ii)In oil (between phases & phase to ground)

0_) DETAILS OF TANK

i) Type of tank

ii) Approximate thickness of sheet

d) Cooling tubes/radiators

iii) Vaccum recommended for hot oil circulation(Torr)

iv)Vaccum to be maintained during oil filling in transformer tank(TORR)

v)Vaccum to which the tank can be subjected without distortion(TORR)

vi) No. of bidirectional wheels provided

vii) Track guage required for the wheels

a) Transverse axis

b) Longitudinal axis

viii) Pressure relief device

a) State whether it is self sealing type(After release of pressure)

b) If self sealing type state the operating pressure

ix) Dia of wheels.

0_) CONSERVATOR

i. Type( with or without air cell)

ii. Total volume (ltrs)

iii. Volume between the highest and lowest levels (ltrs.)

0_) COOLING EQUIPMENT

iii) Type and No. of radiators

iv) Estimated quantity of oil in radiators (ltrs)

0_) BUCHHOLZ RELAY

ii) No.of electrical contacts

iii) Rating of electrical contacts

0_) TEMPERATURE INDICATORS

i) Oil temperature indicator

b) Permissible setting ranges for alarm & trip

c) Range of instrument

d) Number of electrical contacts

e) Rating of contacts

ii)Winding temperature indicator

b) Permissible setting ranges for alarm & trip

c) Range of instrument

d) Number of electrical contacts

e) Rating of contacts

f) Whether remote indicators provided. If so equipments required at purchaser's control room is included

iii) Make of Pressure reducing valve

0_) Details of anti earthquake device provided if any

0_) TAP CHANGING GEAR

ii) Type, designation, standard applicable

iii) Tap voltage as percent of no-load rated KV

c) % variation per step

iv) No. of steps

v) Whether padlock provided

vi) Position of taps on the HV windings

12 (a) Water proof Cable boxes (415 v side)

I) No. of cable boxes

b) Rating of each cable box

iii) Size of cables

12 (b) Water proof Cable boxes (11kV side)

I) No. of cable boxes

b) Rating of cable boxes

iii) Size of cables

i) Net Weight of core

ii)Net weight of

iii) Net weight of copper for

iv) Net weight of insulating oil

v) Net untanking weight of core frame & coils

vi)Volume of insulating oil

vii) Total weight of radiators (without oil)

viii) Transport weight of transformer package with oil but without fittings to be dismantled during transport

ix) Overall dimensions of the major packages

Transformer tank (assembly)

Spare coil tank(HV/LV)

x) Total despatching weight of anciliary equipment

xi) Total weight of transformer when completely assembled

1. Untanking height of core and coils(drawing of lifting arrangement shall be enclosed)

2 a)Dimension of transformer when finally assembled

i) Underbase to topmost point

ii) Overall breadth

iii) Overall length

b) Dimension of transformer during movement from repair bay to its final position (LxBxH)

3. Overall transporting dimensions of largest package (LxBxH)

14 Whether transformer is suitable for installation in the place of existing transformer (Yes/No)