Search results for query: *

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.

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

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...

I am currently experiencing problems with harmonics generated by a 20KVA UPS. The 11th and 13th harmonics are the problem harmonics. I will like to design and install LC harmonic filters. What are the equations for this design and are there alternate solutions to this problem. Thanks.

Is it normal for a domestic 220V 30mA earthleakage unit to trip during a lightning storm? I have experienced problem this on numerous occasions.

Could someone please explain how are harmonics generated. I do understand the sources of harmonics eg. induction machines, solid state devices etc.

Could you explain the operation of a domestic earth leakage unit. Can lights be connect to earth leakage? Will you get nuisance tripping when a light bulb pops? Thanks

How does one calculate the output dc voltage of a 12 pulse rectifier? The secondary of the transformer has two windings phase shifted at 30 degrees to each other and each winding has a voltage of 1.22KV. This feeds into two six stack uncontrolled rectifier. Thanks