NATIONAL SWITCHGEARS

Ambattur, Chennai, Tamil Nadu

The applications are innumerable like starting of slip ring Induction motor / Voltage dropping Resistor / Dynamic Braking Resistor for DC Motors / Traction Duty Resistors for Railways etc.,

They are used in distribution net works for easy Isolation, RMU, Neutral Grounding of multiple Generators etc., They will come with or without Earth switch.

Ever increasing usage of solid state devices like VFD drives and Thyristor controlled Electrical Furnaces etc causes distortion of waveforms with higher frequency Harmonics in supply system resulting in poor quality of power to end users. Harmonic filters are designed to bypass unwanted frequencies using combination of Reactor, Capacitors along with Resistor to achieve better quality power. We specialize in manufacturing medium voltage Filter Resistors for various applications starting from 11 kV onwards.

• Range : Up to 132 kV
• Degree of protection : IP 23 made suitable for outdoor
• Service : Outdoor
• Enclosure Finishing : Galvanized / Stainless steel / Epoxy powder coat painted
• Mounting type : Each phase Resistor mounted on standoff Insulator & stacked one above the other For 3 Phase configuration / Steel Structure Mounted
• Voltage : Up to 36 kV
• Standard followed : BS587 / IEC 60060
• Max. Power Dissipation : Up to 2MW
• Resistive elements : Stainless steel AISI 304 / Fecral (Al-Cr steel)
• Maximum BIL : 400 kV
• Design : Live tank or Earthed tank design
• Normal creepage of porcelain insulator : 25mm/kV

NGR / NER is used to ground the neutral of Transformer / Generator to limit prospective ground fault current to a predetermined safe value. The NGR avoids transient over voltage and gives system stability under fault conditions.

Technical specification :

• Range : 230 V to 66 kV / 8000A
• Degree of protection : IP00 to IP65
• Service : Indoor / Outdoor / Suitable for Highly polluting and corrosive atmosphere
• Enclosure Finishing : Epoxy powder coat painted / Galvanized / Stainless steel (AISI 304 / 316)
• Mounting type : Floor / Steel Structure Mounted
• Duration : 5/10/15/30/60 Sec or Continuous
• Frequency : 50 / 60 Hz
• Standard followed : IEEE - 32
• Termination : Through outdoor porcelain bushing/ cable box
• Types of elements used : Stamped plates / Wire wound / Frame wound / Cast Iron / Edge wound
• Resistive elements : Stainless steel (Cr Ni) / Cr Al alloy (AISI 416)
• Optional accessories : CT / Monitoring Relay / Protection Relay / Space heaters / Vacuum contactor / Disconnector (Motorized/Manual) for Isolation or Changeover/ Zig zag Transformers
• Generator Protection : Single or multiple Generators with Interlock / High resistance Grounding / Through Neutral Grounding Transformers / Disconnector or vacuum contactor Up to 11 kV
• Maximum Temperature : 790C
• Ambient Temperature : 55C

Load Bank is used to test and evaluate performance of Generators and UPS periodically, under various load conditions like full load/Inductive load/ sudden loads and Overload. Sometimes, it is used as Dummy Load for the generator to avoid Glazing of Pistons while running on very low load conditions.

• Range : Up to 12 MW
• Degree of protection : IP 21 / 33
• Service : Indoor / Outdoor
• Enclosure Finishing : Epoxy powder coat painted / Galvanized
• Mounting type : Stationary / Wheel Mounting / Trolley or Trailer Mounted / Container housing
• Voltage : 24 V to 1500 V DC / 24 V to 33 kV for AC 1Ph and 3 Ph
• Frequency : 50 / 60 / 400 Hz
• Standard followed : BS587
• Power Factor : Resistor / Resistor Reactive, Unity / 0.4 PF / 0.8 PF
• Control : Local / Remote, Contactor Switching
• Selection of Loads : Through Push Buttons or PLC / By hand held stations or By Laptop
• Meters : Recording by Laptop / Multifunction Digital meter to indicate
• PF/V/I/KW/KVAR/Hour
• Ventilation : Natural / Fan cooled Vertical / Horizontal

They are used in distribution net works for easy Isolation, RMU, Neutral Grounding of multiple Generators etc., They will come with or without Earth switch.

• Range : Up to 36 kV / 5000 A (Indoor Motorized Disconnectors up to 12000A)
• Degree of protection : IP00 / up to IP65
• Service : Indoor / Outdoor
• Enclosure Finishing : Epoxy powder coat painted / Galvanized / Stainless steel
• Mounting type : Wall / Floor / Steel Structure Mounted
• Motorized version : Operate at 24/48/60/110/220/230 V AC / DC
• Standard followed : IEC 62271 - 103
• No. of Poles : 1 Pole / 3 Pole
• Type of load : On load (Switch Disconnectors) / Offload (Disconnector)
• Operation : Manual / Motorized
• Other accessories : Earth switch interlocked with Main switch or Independent, Shunt Trips/Fuse with trip, Adequate auxiliary NO+NC Contacts
• Type : Singe Break or Double Break (Centre post Rotating type) for outdoor applications