Voltage Transformers testing and commissioning Guidelines

basicelectricaldesign
Voltage Transformers ratio check

Potential / Voltage transformers Testing and Pre-Commissioning Check   Potential /Voltage transformers can be broadly divided in to two type : Indoor and outdoor type. Indoor type – Cast resin. Outdoor type – Live tank, Oil cooled.These can be of electromagnetic of capacitive voltage transformer type (CVT). PT rating  are specified as follows –  1) Metering Core-  132 KV /3 : 100v / 3 – nominal ratio 100 VA – Rated burden Class 1.0- Accuracy is 1 %, between 80 % and 120 % of rated voltage and with burdens between 25…

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Advantage and Dielectric properties of SF6 circuit breaker

basicelectricaldesign

Basic Information about SF6 Circuit Breakers Some of the outstanding properties of SF6 circuit breaker gas are Electrical and Thermal Properties High dielectric strength Outstanding arc-quenching ability Excellent thermal stability and Good thermal conductivity Physical and chemical attributes Chemically inert Non-toxic non-inflamable non-corrosive non condensable at low temperature Advantages of SF6 circuit breaker gas when used in power switch gear Increase safety Reduction in size Simplified design Reduction in weight Reliability of operation Noiseless operation Ease of installation Ease of handling and Ease of maintenance Dielectric Properties OF SF6 At atmospheric…

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Current transformers Testing and Commissioning Guidelines

basicelectricaldesign

Commissioning Procedure for Current Transformers Current transformers (CTs) can be broadly divided in to two type, Indoor and outdoor type. Indoor type – Cast resin : wound type and window type. Outdoor type – Live tank , Oil cooled and dead tank , oil cooled. CT rating are specified as follows- Metering core 200/5 – nominal ratio 15VA – Rated burden : the maximum burden (i.e. impedance) that may be connected on the CT secondary side. Class 1.0- Accuracy at 100% rated current and burden is 1.0% Protection Core 200/5-…

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Power Transformer Testing and Commissioning Guidelines(Oil Type)

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Testing of stability of transformer differential Scheme

Commissioning Procedure Of Power Transformer  In Transformer testing it can be classified into power and distribution transformers. It Rating plate show nominal voltage, current of  primary and secondary voltage at various of the tap changer, connection symbols ( vector group), % impedance weight of oil etc. Before starting transformer testing some of per-commissioning checks a physical inspection of transformer is to be carried out along with the general arrangement drawing.The parts mentioned on the drawing are to be checked for physical mounting. Check the following points before start the  Transformer…

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How to select a transformer sizing or rating for commercial and industrial ?

basicelectricaldesign
Transformer Sizing calculation

Calculate Transformer sizing and Voltage drop  with regulation at starting of large size motor Procedure:- The transformer sizing is done base on the following condition. a) peak load calculated from continuous ,intermittent & standby. b) 10% spare capacity for future loads. c) Load requirement with highest rated Motor started on DOL. 1:-Calculation of total peak load Total connected load as per transformer-sizing-load-summary given below Continuous load (E) Intermittent load (F) Stand by load (G) Total KW 222.74 Total kVR 138.04 Total KVA 262.05 Total KW 1871.61 Total KVAR 1159.92 Total…

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