Specifications

Enquiry Specification for Wagon Tippler with Side Arm Charger and Associated works
NRO/CON/WT/533
EPI – New Delhi Volume-2B, Rev.0 Page 38 of 63
7.0 Electrical design
(i) Power Supply
• 415 V +10 & -15% • 50 Hz +/-6% • 3-
phase, 4-wire AC, • 50 kA for 1 second,
solidly earthed.
(ii) Starting DOL or thyristor converter (ASTAT or
SIMOTRAS or equv.) Soft starter feature
through static voltage control/VVVF as per
application
(iii)
Min Voltage for Start &
Run
80 % of rated voltage at terminal
(iv) Breakdown or pullout
torque
Pull out torque of the intermittent duty
motors to be not less than 300% of the
rated torque at 40% duty factor.
(vi) Starting current <= 600% Rated current
(vii) Duty Duty cycle shall not be less than S4-40% ,
with a minimum of 150 starts per hour
(600 starts / hour for charging cranes and
other process cranes) . For conveyor
application S-6 duty.
(viii) Starts/Hour permissibe Mechanically and electrically shall be
suitable for required number of switching /
reversals or starts per hour.
(ix) Max speed variation 250 % of rated synchronous speed at high
accelerating rates and rapid reversals .
(x) Max speed
250 % of rated speed or 2000 rpm
whichever is less .
(xi) Rated synchronous
speed
Motors shall be of low synchronous speed
for ease of dynamic balancing of hoist
rotating unit . The motor speed preferably
shall be as follows : Upto 37 KW :1000 rpm
Above 37 KW upto 90 KW :750 rpm Above
90 KW :600 rpm
(xii) Overload capacity 1.5 times the rated current for 2 minutes
(xiv) Void
(xvi) Derating Motor designed at 50 deg.C shall be
derated suitably for mentioned ambient
temperature .
(xvii) Insulation Class H
(xviii) Torque Type Normal / High / High slip type / Stall
Torque type (as required for the specific
application)
(xix) Space Heater Out door motors above 45 kW Indoor Motor
above 110 kW
(xx) Over temperature
detection and protection.
Slip ring motors for essential drives to be
provided with Pt 100 resistance
thermometers / thermocouples or
thermistors .
(xxi) No. of Poles Not applicable
(xxii) Testing
As per approved QAP during engineering
stage .