Recent content by govender1

I would like to know what is integral earthing. We have recently installed two 6.6kV vacuum circuit breakers and the contractor quoted an additional cost for integral earthing. I would like to know the purpose and benefits of integral earthing and is there other types of earthing regarding...

I have a battery room that houses 53 lead acid cells of 2.2Vper cell and 214 amp-hour. I would like to know if this installation must be considered an Hazardous Location. What constitutes an hazardous location? Thanks

Please provide details of forums where I could discuss issues of railway electrification. I have many railway related queries and hopefully get in touch with people who work for the railways as well.

We have recently repaired(rewound)a 1 MVA,22kV to 6.6Kv,3 phase power transformer. After energising it, it came out on bucholz three times within a space of a month.A DGA test proved that everything is normal. What could be wrong or what am I missing? Govender1

My question relates to phase failure and how the rectifier operates. Lets take a situation where a three phase rectifier is feeding a load at (3kV dc)(traction motor)and suddenly the rectifier looses one of its input phases. What happens to the output of the rectifier? Does the rectifier...

Could some one please explain what is tan delta testing of transformers. At my work environment, my colleagues are adamant to conduct these tests as they feel these tests damage the transformers. Thanks

Could someone please explain the meaning behind the KA rating of a circuit breaker and how does one select a circuit breaker. Thanks in advance.

Is there a standard regarding how information is displayed on name plates of transformers?

I'm in the process of designing a rectifier and a transformer ccmobination for a traction substation. What sites are available that I can use as refernce to assist me in my calculations.

What are some of the causes of a low power factor. Usually the power factor at most of our traction substations is .96 lagging however one particular substation is 0.5. Substation layout: Primary of transformer : 88 kV 3340kVA Secondary : 2x2364 V note there two secondary windings 2x2362 kVA...

Excuse my ignorance. Can some explain what is the meaning of fault level with reference to power transformers.

Thanks guys for the valuable information. Note that the transformers are approximately 8m apart will this still create circulating currents. The impedance of the transformers are 7.69% and 8% respectively. Is there an impedance tolerance where paralleling the transformers will not have any...

What are the effects of operating two power transformers of different impedances in parallel?

jwertman, how do you arrive at the figure of 173% full load current?

I would like to know from someone if an incoming phase is burnt off will a three phase rectifier continue to operate and will this cause the rectifier to go into over load. Recently we had a phase failure and the rectifier diodes popped. I know in a three phase induction motor, if the motor...