Voltage: 11/22/33 kv class capacities up to 7.5 MVA
Applications: For the protection of electric appliances or devices or equipment from overloading of voltage
It is a very altogether different product basically a combination of Standard Distribution Transformer and HT Automatic Voltage Regulator. The Standard Transformer with OLTC can correct limited voltage variation in certain steps whereas Built-in operates steplessly monitoring the output voltage continuously. The incoming fluctuating H.T. supply is initially stabilized and then fed to the stepdown transformer and thereby the L.T. Output is maintained within +-1% accuracy. Built - in has the following advantages:
Dry type transformer is non-explosive fire resistant, air insulated, and are cooled by natural circulation of air through ducts provide in the windings. High temperature and high dielectric insulating materials like glass fiber reinforced, Nomex insulating tapes are used in such a way that the entire assembly is capable of withstanding high electrical and mechanical stresses with the good dissipation of heat causing the low temperature rise within the prescribed limit of insulation class.
The Dry Type Transformer are manufactured to comply with National International Standards BIS, IS 11171, IEC 76. Description:
The winding is made up of electrolytic Grade, Soft and bright annealed copper conductors covered with Nomex insulating tapes. The wound coils are preheating and impregnated with silicon varnish under vacuum pressure and undergo a curing cycle. The low voltage coils are wound over glass fiber reinforced cylinder having high mechanical strength. The high voltage coils are supported by yoke on glazed porcelain or resin insulators. The core is made of CRGO silicon steel laminations duly annealed after shearing and assembled in mitered construction for low “NO LOAD” LOSS.
Tapping- On Load Tap Changer to provide +5% to -15% Taps in steps of 1.25% on the H.T. Side. Else, Off Circuit Tap Links for ± 5% Taps on H.T. Side in steps of 2.5% each.
The yoke frame has adjustable pressure plates to clamp & secure the coils adequately. Lifting arrangements provide on the top yoke frame so that the core and coil assembly is lifted. OFF-CIRCUIT TAMPING if required are provided on HV winding and terminated on fiberglass terminal board for changing the transformer ratio in “OFF CKT” position.
Applications: Fire safety and environmental aspects are of increasing importance especially in respect of energy supply. The substitution of oil-filled transformers by dry type transformers is one of the most important steps towards it. Dry Type Transformer is used when it has to be located near load center and in a fire hazardous place. As there is no oil used in the transformer and special type of fire resistant insulation are used for the windings the fire risk is considerably reduced.
Isolation Transformers eliminate such noises and attenuates the spikes to minimal values, providing complete protection against such electrical disturbances. It consists of double wound Transformers with Extremely low coupling capacitance to isolate the voltage spikes and reduce noise from mains with extremely high insulation resistance. The turn ratio of Isolation transformer is 1:1. It is generally installed with the separate machines.
Switching of Electrical Equipments in industrial and commercial Generates spikes up to 10000 Volts and high-frequency Noises thus disturbing the sine wave output. The spikes can cause the failure of Thyristor, Microprocessor or other sensitive devices.
The High-frequency noise can interface with digital – Electronic Equipment Causing data corruption erratic behaviors, loss of memories etc…
Isolation Transformers eliminate such noises and attenuates the spikes to minimal values, providing complete protection against such electrical disturbances. It consists of double wound Transformers with Extremely low coupling capacitance to isolate the voltage spikes and reduce noise from mains with extremely high insulation resistance. It is generally installed with the separate machines.