Transformer Volt Drop Start Up Regulation

CALCULATION FOR TRANSFORMER VOLTAGE DROP DUE TO MOTOR STARTING DUTY

EQUIVALENT CIRCUIT

TRFR. REACTANCE

VD

VD sin

VD

U

VECTOR DIAGRAM

M

V

I V U

V TRANSFORMER NO LOAD VOLTAGE

= U

TRANSFORMER LOAD VOLTAGE

= V

TRANSFORMER VOLT DROP

VD cos

= VD

DRIVE DESCRIPTION MOTOR TAG. MOTOR SERIAL No. MOTOR MANUFACTURER

INPUT DATA TRANSFORMER SECONDARY NO LOAD VOLTAGE (U)

6600

MOTOR STARTING POWER FACTOR

0.75

PRIMARY VOLTAGE

33000

MOTOR FULL LOAD POWER FACTOR

0.85

PRIMARY FLC (AMPS)

140.0

MOTOR EFFICIENCY

0.95

% IMPEDANCE VOLTAGE

8.5

TRANSFORMER kVA

8000

VECTOR GROUP

Dyn11

TRANSFORMER BASE LOAD (kVA)

7800

RATING (kVA)

8000

8.5

SECONDARY NO-LOAD

MOTOR kW

1340

SECONDARY FLC (AMPS)

700

MOTOR RATED VOLTAGE

6600 BASE LOAD (kVA)

7800

CALCULATED DATA

OUTPUT POWER (kW)

1340

MOTOR

FULL LOAD CURRENT (AMPS)

145

RATED VOLTAGE

6600

START POWER FACTOR

0.75

RUN POWER FACTOR

0.85

EFFICIENCY

0.95

TRANSFORMER % IMPEDANCE

MOTOR LOCKED ROTOR CURRENT RATIO

1.5

145

FULL LOAD CURRENT

218

STARTING CURRENT

TRANSFORMER TRANSFORMER FULL LOAD CURRENT

700

VOLTAGE

6600

M

VOLT DROP AT TRANSFORMER SECONDARY BUSHINGS TRANSFORMER VOLT DROP (VD) TRANSFORMER LOAD VOLTAGE (V) PERCENTAGE VOLT DROP

6427.3 257

96.11

REMARKS:

Prepared by: Checked by:

PROJECT:

PRAMOD WANKHADE

Date:

6600