What is the reason for using high KVA transformers in electrical heaters?

In summary, the conversation discusses the challenges of building a thin film deposition setup for coating telescope lenses with aluminium. The Flash evaporation process requires a high current, leading to a high cost for a large KVA transformer. The question is raised about whether it is possible to use a smaller, cheaper transformer with more primary coils to draw the same amount of current. It is explained that adding more primary coils will lower the voltage at the secondary, resulting in a significantly lower heat output. The conversation also mentions the importance of the gauge of the wire in determining the VA rating of the transformer. It is suggested that this information can help answer the remaining questions.
  • #1
Umar Awan
7
0
Note: I have a feeling this is below Electrical Engineering requirements, but I couldn't find a more suitable category, so I think I'll extort the advantages of a forum base with electrical understanding more than I think may be required(ofcoarse I know very little about the field, so I may fall short first, knowledge wise).

Backstory: I have been planning to build a thin film deposition setup for coating my telescope lenses with aluminium. The Flash evaporation process requires a very high current and my whole setup has got me running short on my budget. I figure I could save a quite a bit of money if I cut out on that big high KVA transformer I have requested a quote for recently.

Question: What is it that forces electrical heater manufacturers to buy such high KVA transformers for a high current when the same amount of current could been drawn from a cheaper, small KVA transformer using more coils in the primary?

I figure coil losses would likely be the negligebely same either ways, so could it somehow possibly *fingers-crossed*be the physical limitation of fitting a high gauge coil in a small transformer(or a lot of primary coil)? Or is it because say, adding infinitely(very large) many primary windings may get to the point where resisitive losses in primary cost more than simply buying a transformer with more KVA? Or is it something to do with the transformer core?

I would also appreciate it if there are some formula's for calculating when its prefferable to stick to High KVA transformer, over adding a very large number of primary windings and increasing costs more than high KVA transformers possibly could.

Please don't get discouraged with the effort of teaching my V=IR if I have made some basic errors. Hehe, I may be worse. Also forgive my apologist overtone and head to the reply section

Thanks in advance.

Umar Awan
 
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  • #2
Adding more coils to the primary and not the secondary will give you a lower voltage at the secondary. The power output of a heater is V2/I. Lowering the voltage lowers the heat output dramatically.

Adding more to each while reducing the physical size of the transformer will give you a lower VA rating as that is strongly dependent on the gauge of the wire. More turns in a smaller package necessitates a thinner wire.

I think that should allow you to answer the rest of you questions.

BoB
 

Related to What is the reason for using high KVA transformers in electrical heaters?

What is the definition of "Transformer max current"?

Transformer max current refers to the maximum amount of electrical current that a transformer can safely handle without overheating or causing damage to the transformer.

Why is "Transformer max current" important?

Knowing the transformer max current is important because it helps determine the appropriate size and rating of a transformer for a specific electrical load. If the current exceeds the transformer's max current, it can lead to overheating and potential fires.

How is "Transformer max current" calculated?

Transformer max current can be calculated by dividing the transformer's power rating (in volt-amperes) by its voltage rating. For example, a transformer with a power rating of 1000 VA and a voltage rating of 120V would have a max current of 8.33 amps (1000 VA / 120V = 8.33 amps).

Can "Transformer max current" be exceeded?

It is not recommended to exceed the transformer max current as it can cause damage to the transformer and potentially lead to electrical hazards. However, certain transformers may have built-in overload protection that allows for temporary increases in current for short periods of time.

What factors can affect "Transformer max current"?

The main factors that can affect transformer max current include the transformer's design and materials, operating temperature, ambient temperature, and the type of load it is powering. It is important to consider these factors when choosing a transformer for a specific application.

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