1. Q1) Is HFSR is a standard Technology and method for motor Starting?
  1. A1) Yes, HFSR is the most proven and standard Technology [As per IEC 60289/ IS 5553 (part3)] implemented for motor Soft Starter. User must make sure that the HFSR is Air core reactor type for high efficiency and linear acceleration.
  2. HFSR is the technical name of the product and not the brand name.

There are many manufacturers which manufacture HFSR Soft Starter with various names and use inferior Technology of Iron core and try to give fancy names like Flex Control, magnet amplifier etc.

 

  1. Q2) How long have you been designing and manufacturing HFSR?
  1. A2) JAYASHREE is the pioneer company and has been manufacturing HFSR starter since 1978.
  2. Thousands of HFSR units are running trouble free for over the last 30 years.

 

  1. Q3) What are the Typical ratings of the motors which can  be started using HFSR Soft Starter?
  1. A3) Typically, a 25Kw 415V to 15MW 11KV motors are best benefited by the HFSR Soft Starters.

 

  1. Q4) What are the levels of harmonics generated by HFSR? Is it the same and dangerous as it is there in HT- Electronic Soft Starters?
  1. A4) As the name Harmonics free series Reactor itself explains the HFSR is 100% Harmonics free.Infact, the Air core Reactor itself acts as a harmonics filter to save the systems and motor from Harmonics. To achieve the same, the Soft Starter is essentially designed with Air core Technology with pure copper conductor.

On the other hand, if Iron Core is used in Soft Starter design, then the system suffers from the following hazards
1)     Iron losses
2)     Non Linear acceleration
3)     Noise
4)     Heat Generation.
5)     Vibration
6)     Core Saturation
7)     Eddy currents
8)     Poor Efficiency.

Hence Soft starter essentially has to be designed by Air Core.

 

  1. Q5) Is it possible to adjust the starting Current and time on site?
  1. A5) Yes, with carefully designed taps, the Starting time, torque current can be adjusted on site by HFSR starters.

 

  1. Q6) How is it ensured that the current has dropped to FLC during Soft Start? Is it Automatic or has to be adjusted during commissioning?
  1. A6) A unique Technology of JAYASHREE make CTSR (Current and Temperature Scanning Relay) senses and decides the by pass event to provide a jerk less smooth by pass. No need to go for trials and errors during commissioning.

 

  1. Q7) Is HFSR an ‘Off the Shelf’ product or a tailor made product?
  1. A7) The motor datasheet and load-motor T-S curves have to be studied carefully and Soft Starter T-S curves have to be plotted before manufacturing of Soft Starter. Hence it is essentially a Tailor made solution for any specific motor / application.

 

  1. Q8) Is it necessary to have Soft Starter T- S curves before installing the Soft Starter?
  1. A8) Yes, any manufacture should supply the Soft Starter T- S curves informing the starting current, starting time, Torque, acceleration in form of curves etc. data before installation.

 

  1. Q9) Is it possible to reduce the starting current to any extent?
  1. A9) Yes, motor always takes a defined minimum starting current to match the load requirement. But with the use of JAYASHREE’S dynamic compensator, the current can be reduced further.

 

  1. Q10) What is the principle of the HFSR?
  1. A10) The motor terminal voltage is reduced up to 30% of full voltage as per the torque requirement with the help of Air core reactors. This series impedance is dynamically adjusted as per the motor speed, back EMF and current to deliver highly efficient, harmonics free linear acceleration of the motor.

 

  1. Q11) What are the advantages of HFSR?
      1. A11) Smooth, jerk less, reduced current starting of motor.
      2. Less Temperature rise in the motor, hence more number of starts.
      3. Reduction in the Transformer/ generator size.
      4. Power factor improvement during starting with the help of dynamic compensator.
      5. Increased life for bearing, coupling etc.

 

  1. Q12) What is the cooling system required for HFSR?
  1. A12) HFSR is Natural Air cooled, and works up to 55o C ambient temp.

 

  1. Q13) What is the periodic maintenance required for HFSR?
  1. A13) Practically NIL, as there are no mechanical moving parts, no iron core and heat generation.

 

  1. Q14) Can HFSR be used for Soft Stop?
  1. A14) Yes, with some modifications HFSR can give a smooth Soft stop.

 

 Q15) What are the Limitations of HFSR ?

  1. A15) HFSR is a tailor made soft starter. Hence interchangeability with motors is not possible,

Baring this limitation, it is superior then any other starter present today  as its less complicated, easy to understand, light weight and flexible to design and customize.