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Because a transformer is a big lump of metal that takes time heat up, so if the load is on and off in a short time, the load rating can be exceeded.
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30MVA power transformer can uprated to what extend?
You need to discuss with a transformer manufacturer, because modifications will need to be made. The transformer name plate will say the top rating of the transformer (I'm assuming in this case it is 30MVA). This top rating is generally limitted by heating. So to uprate, you need to modify the cooling system - add more or bigger fans, add pumps, etc. In my area, loading as high as 125% of max rating of transformers is allowed on a "short term" basis (in general), which gives system operators time to shift load without dropping customers. If 30MVA is the base rating, I see typical values of 166% and 186% for ONAF1 and ONAF2 (oil natural, air forced level #1 and #2). This is something that is specified when ordering the transformer, so it may be different in your case (look at the nameplate!). The 30MVA base transformers I've seen, therefore are rated at 30/49.8/56MVA (at 65 degree C).
How do you find capacity of transformer?
If the load is single equipment, calculating the capacity of the generator or transformer is fairly straight forward. If the load is mix of various several different equipment it would be more complicated to arrive at transformer / Generator capacity. Complexity increases if you have to estimate some future unknown loads. The rating of the generator or transformer should be such that it is loaded optimally, average being say 80 to 95 %. Since maximum efficiency of generator or transformer generally occur at these range. Also this ensures that it is not overloaded continuously and there is room for occasional short time full load too. You need to check the data sheet of the transformer or generator for more correct information. One need to know the maximum load or peak load, average load and diversity factor and load factor. These values drive the decision on the rating of the transformer or Generator.
Why earthing transformer is zigzag connection?
A zigzag transformer is used in connection with 3 phase and is made up of 6 coils connected in a "Y" manner. Each leg of the "Y" is made up of a coil on a different phase leg of the transformer. The neutral formed by the zigzag connection is very stable. Therefore, this type of transformer, or in some cases an auto transformer, lends itself very well for establishing a neutral for an ungrounded 3 phase system. Many times this type of transformer or auto transformer, lends itself very well for establishing a neutral for an ungrounded 3 phase system. Many times this type of transformer or auto transformer will carry a fairly large rating, yet physically be relatively small. This particularly applies in connection with grounding applications. The reason for this small size in relation to the nameplate KVA rating is due to the fact that many types of grounding auto transformers are rated for 2 seconds. This is based on the time to operate an overcurrent protection device such as a breaker. Zigzag transformers used to be employed to enable size reductions in drive motor systems due to the stable wave form they present. Other means are now more common, such as 6 phase star.
What is a welding transformer?
A welding transformer is an electrical transformer used in welding power supply. It pulls relatively low current drawn from the mains power (typically limited to 15 A to avoid tripping the circuit breaker) and converts it to the typical 50 A to 500 A used in arc welding and higher currents used in spot welding. The main difference between a Normal Step Down Transformer & a Welding transformer , is Not only to Step Down ( lower ) the outlet supply voltage and at the same time increase the Available Output Circuit Current, but to be also able withstand the Short Circuit Conditions on the Welding Output Side and especially for the Magnetic ( Iron Lamination Core ) Part of the Transformer. This Magnetic Path difference prevents the Supply side Electrical Circuit from Oveloading , espcially during the Striking of the Arc, when the Welding Electrode & the Welding Job touch to initiate an Arc, after which the Welding Electrode is lifted slightly by Experience, to maintain the required weld flow. A Normal Transformer of equivalent rating will not be able witstand this operation without burning out.
What is welding transformer?
A welding transformer is an electrical transformer used in welding power supply. It pulls relatively low current drawn from the mains power (typically limited to 15 A to avoid tripping the circuit breaker) and converts it to the typical 50 A to 500 A used in arc welding and higher currents used in spot welding. The main difference between a Normal Step Down Transformer & a Welding transformer , is Not only to Step Down ( lower ) the outlet supply voltage and at the same time increase the Available Output Circuit Current, but to be also able withstand the Short Circuit Conditions on the Welding Output Side and especially for the Magnetic ( Iron Lamination Core ) Part of the Transformer. This Magnetic Path difference prevents the Supply side Electrical Circuit from Oveloading , espcially during the Striking of the Arc, when the Welding Electrode & the Welding Job touch to initiate an Arc, after which the Welding Electrode is lifted slightly by Experience, to maintain the required weld flow. A Normal Transformer of equivalent rating will not be able witstand this operation without burning out.
How long did it take to make transformer?
The time to make a trnsformer depends on the size, rating, type.
30MVA power transformer can uprated to what extend?
You need to discuss with a transformer manufacturer, because modifications will need to be made. The transformer name plate will say the top rating of the transformer (I'm assuming in this case it is 30MVA). This top rating is generally limitted by heating. So to uprate, you need to modify the cooling system - add more or bigger fans, add pumps, etc. In my area, loading as high as 125% of max rating of transformers is allowed on a "short term" basis (in general), which gives system operators time to shift load without dropping customers. If 30MVA is the base rating, I see typical values of 166% and 186% for ONAF1 and ONAF2 (oil natural, air forced level #1 and #2). This is something that is specified when ordering the transformer, so it may be different in your case (look at the nameplate!). The 30MVA base transformers I've seen, therefore are rated at 30/49.8/56MVA (at 65 degree C).
What will happen you f the rated power of transformer is changed?
You cannot 'change' the 'rated power' of a transformer except by changing the transformer for another one. You can, though, operate the transformer below its rated power or, for short periods of time, operate the transformer aboveits rated power.
How do you calculate short time rating of dc motor?
stick urwein in it
What losses can be measured in a short circuit test of a transformer?
Winding copper losses of a transformer can be measured in a short circuit test of a transformer. Impedance voltage is given to the primary and the secondary is often shortcircuited. (some times the reverse is done of this). Full load currents are made to flow in both primary and secondary circuits. This current flow heats up the 2 windings of the transformer. Power consumed at this time gives the transformer copper losses.
How do you find capacity of transformer?
If the load is single equipment, calculating the capacity of the generator or transformer is fairly straight forward. If the load is mix of various several different equipment it would be more complicated to arrive at transformer / Generator capacity. Complexity increases if you have to estimate some future unknown loads. The rating of the generator or transformer should be such that it is loaded optimally, average being say 80 to 95 %. Since maximum efficiency of generator or transformer generally occur at these range. Also this ensures that it is not overloaded continuously and there is room for occasional short time full load too. You need to check the data sheet of the transformer or generator for more correct information. One need to know the maximum load or peak load, average load and diversity factor and load factor. These values drive the decision on the rating of the transformer or Generator.
What happens to a transformer when it is first connected to a power line Can anything be done to mitigate this problem?
If rating is correct, terminal connections are correct, if safety devices are in place, if device is a standard with necessary requrement, it should not be problem to connect a transformer first time.
What is the result when 3 kva power requirement is being supplied by 250 kva transformer?
The result is that the transformer runs cool and contented. The '250 KVA' rating on the transformer is its maximum ability to transfer power from its input to its output without overheating, NOT an amount of power always running through it. If the 3 KVA load happens to be the only thing connected to the transformer at the time, then only 3 KVA flows into the transformer from the primary line, and only 3 KVA leaves the transformer secondary.
When a transformer winding suffers a short circuit the adjoining turns of the same winding experiences?
A short circuit between adjacent turns of the same winding will cause the turns ratio of the transformer to change. A short circuit of this nature may not cause the transformer to become disconnected, so the situation could last for a long time. In larger utility transformers, the gases formed by the arcing between turns will collect in the Buchholz relay, situated between the transformer and its expansion tank, which will then initiate an alarm inside the substation.
What does a high fico score mean?
A high fico score means you could have anywhere from a good credit rating to an excellent credit rating. If you have a high fico score, it means you pay your bills on time with no late or missing payments.
How can ready to serve food preserve by high temperature short time?
how can apply high temperature short time preservation method to ready to serve foosd
What does HTST stand for?
High-temperature-short-time
