technical NOTES

14.3 VFD Proposed Concept:
Belt Conveyor /Deep Pan Conveyor /Bucket Elevators drive with conventional
system limitations & Disadvantages can be overcome by replacing with VFD starter,
addition to that we will get better system reliability, Process Optimization & Control
& Power saving.

Following are the Major Electro-Mechanical Hardware’s required to operate Belt
Conveyor / DPC/Bucket Elevators with VFD

• Direct Coupling – As No Fluid coupling requirement with the system, all
  above mentioned limitations & getting better reliability & energy saving on
  account of slippage (Approx. 2% to 6%).


• VFD system efficiency is 98%.


• Over speed of additional 10% can be achieved with VFD system, in case of
  increasing capacity of plant without changing of gear box.


• The VFD coupled system is much more efficient than a fluid coupled system
  for speed control as well as starting torque.


• Keeps starting current in control: A VFD has the capability of starting the
  motor at zero voltage and frequency, which keeps a check on motor winding
  flexing and heat generation. This helps in extending the motor life.


• Limits and adjusts torque: The drive is capable of limiting and adjusting the
  amount of torque so the AC motor never surpasses this limit. This protects
  machinery from damage and protects the process or product.

14.4 Comparison of Conventional System vs VFD Concept

S. N. Particulars Conventional System VFD Concept

1 Initial Investment

Type of Stator IMCC-DOL feeder with pro-V VFD

Coupling Fluid Coupling Direct Coupled

Gear Box Design As per shaft power with safety margin As per shaft power with safety margin

Power Cable

Higher size Power cable

required as per motor rated

power

Lower size Power

cable required as per

motor rated power

2 Power Consumption

Speed Control &

Reduction Not Possible

Possible 10-110%

possible & getting

Power Saving

Losses 6% of rated power on account of slip

2% of rated

power loss across

the devices