Vapromatic Liquid Rotor Resistance Starter

Construction of Vapromatic Type Liquid Rotor Resistance Starter :- The LRS (V) is a rectangular tank having electrolyte in it and works on the principle of resistance cutting based on different resistivity of electrolyte at different temperatures. The tank will be constructed from heavy gauge sheet steel and have enclosure protection of IP-42. The electrodes will be of zinc passivated M.S. suitably supported with insulator and bushings to sustain stress at the time of external faults. The fixed electrodes are mounted at the bottom of the tank and adjustable electrodes will be mounted at the top of the electrolyte tank through insulating bushing. The inside surface of the electrolyte tank will be painted with anticorrosive epoxy paint. Polypropylene phase barriers will be provided to prevent circulating current between the electrodes. Also the metallic resistance used for bringing the motor from 80% speed to rated speed would be mounted in a separate chamber which would be able to dissipate the generated heat. The tank will have accessories e.g. drain valve with brass plug at the bottom, separate plug for filling of electrolyte etc. Painting will be done by Hand Spray Gun M/cs with approved paint shade.
Main supply will be of 415 Volts and control supply for LRS (V) will be 230 or 110Volts and accordingly contactor coils would be of 230 or 110Volts only. Initial position and full speed position indicating contactors each having 2NO and 2NC potential free contacts will be provided for sequence interlocking. Electrolyte level and temperature sensor with alarm and trip contacts will be provided for sequence interlocking.
The LRS (V) will be complete with ample sized cable box and will be suitable for termination of PVC/XLPE Aluminum conductor cable. The terminal box will have detachable gland plate.
Control Panel having Switch-gear Components as :-

• Temperature and Level Sensors.
• Initial and Final position contactors with multiply contacts.
• Two nos. of Electronic Timers of ‘Reputed make’, one for adjusting the time for Motor to reach up to 80% speed and other one is used if final shorting contactor is not operated after predetermined interval.
• Adequate rating and quantity of Step & Final Power contactor of ‘Reputed make’ for smooth cutting of resistance and for final short-circuiting.
• Control Transformer (415V/230 or 110V) with control fuses (if required). Indicating Lamps (LED type) and TBs.

Interlocking for LRS (V) :

• Motor would be ready for starting in RFS (Control Supply Healthy, Temp. within Limits).
• Zero Position (RFS, both shorting contactors in un-operated position)
• Final Position (If motor shorting not done in predetermined interval)

The Potential Free Contacts are required for Interlocks with:

• HT/LT Panel : HT/LT to Trip & Start Signal
• DCS : LRS (V) Healthy, Resistance IN/OUT, Liquid Level Low, Liquid Temp. High

Indications (with LED type Lamps :

• Ready to Start
• Zero Position
• LRS (V) in Service
• Liquid Level Low
• Liquid Temperature High.

Terminal Blocks : All LRS (V) units will be provided with separate Terminal Blocks for termination of wires for External Connections.
Inspection and Testing : All routine tests and temperature rise tests as per relevant British Standards & IS.