Calculating The Kva Rating Required For A Transformer Installation

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Calculating The Kva Rating Required For A
Transformer Installation
Almost every industry, from basic manufacturing
industries to critical healthcare facilities and
testing laboratories, requires high-quality
reliable transformers to keep their operations
running safely and efficiently. Larger
facilities require larger amounts of power, which
means more dependable transformers to convert
the energy coming from the power plant, into a
form that can be used for the equipment. But, in
order to have the transformers do so effectively,
businesses need to know how much power their
particular transformers can give them. It is the
transformers rating that provides this
information. The rating, or size, is the
transformers power level in kilovolt-amperes,
denoted by kVA. You need to select a transformer
with the correct kVA for your needs. If not, you
may run the risk of damaging your valuable
equipment. Seems difficult? But fortunately,
its not as difficult as it sounds. In fact,
sizing your transformer is relatively simple.
You just need to use a simple straightforward
formula to generate your kVA requirements, using
the current and voltage of your electrical load.
Lets help you know how you can calculate the
required kVA rating. Calculating the kVA
value Transformers come in two basic ratings
volt-amperes (VA) and kilovolt- amperes (kVA). A
transformer with a 100 VA rating can handle 100
volts at one
2
ampere of current. Similarly, a transformer with
a 1.0 kVA rating (1000 volt- amperes) can handle
100 volts at 10 amperes of current. To determine
your appropriate kVA size, you need to make a
few calculations, based on your electrical
schematic. There are two main measurements that
youll need, that of the voltage (V) and of the
current (I). Voltage is the electrical load that
connects to the secondary winding, and current
is the flow that the electrical load requires.
Both these values can be determined simply by
looking at the electrical schematic. Once these
two values have been determined, you can then use
them to figure out the loads power
requirements. To do that, youll need to multiple
the voltage with the load, and then divide the
number by 1000 hence, the formula being (V
I) / 1000 But, the number calculated here will be
in kilowatts. So, this value needs to be
converted into kVA (kilovolt-amperes). To do so,
the calculated value will need to be divided by
0.8. Now, why 0.8, you may ask. The reason is
because starting a device generally requires
more current than what is required for the
functioning. To account for this additional
current requirement, its wise to put a start
factor into your calculation. And, a good rule of
thumb here is to multiply the voltage with the
amperage, and then multiply it by an additional
start factor of 125 (which is the same as
dividing it by 0.8). So, the formula becomes
(V I) / 1000 / 0.8 The value received from
the above calculation is the kVA value that you
need. Now, most kVA ratings are whole numbers,
mostly in the multiple of 5 or 10, such as 5
kVA, 10 kVA, 15 kVA, 150 kVA, etc. So, when
youve calculated the value, you can then round
it off to the nearest higher whole number to
get your appropriate kVA rating. The most
standard kVA values available for transformers
are 3, 6, 9, 15, 30, 45, 75, 150, 225, 300, 500,
750, and 1000 kVA. However, if you start your
transformer often, say more than once every
hour, you then need a kVA even larger than your
calculated size. And, if you are working with
specialized loads, your kVA requirements may be
even higher. Hence, for specialized
applications, it is always wise to consult a
professional for advice on the right value of
kVA required. Calculating the kVA value for
three-phase transformers
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One thing to note here is that the equation for
three-phase transformers is slightly different
than the single-phase general transformer as
spoken of above. For three-phase transformers,
once you have determined your voltage and
current, you need to multiply the two values,
further multiplying the value with a constant
1.732, before dividing the value by 1000. The
number 1.732 is the square root of three,
truncated to 3 decimal places, clearly being the
right way to calculate the value for a three
phase transformer. So, the formula for a
three-phase transformer becomes (V l 1.732)
/ 1000 Where to find the perfect transformer? No
matter what your transformer size and type, you
can always partner with Miracle Electronics to
reap the benefits of high-performing,
high-quality transformers. We provide a range of
transformer products to keep your business
operating smoothly. We also build custom-made
transformers to meet your unique needs and
specifications. So, whatever your industry,
whatever your application, and whatever your
requirements, even if youre looking for
toroidal transformers of higher kVA, were here
to serve you with the finest quality big
toroidal power transformers! Whats more? Every
transformer manufactured at our premises are made
of the best quality materials, and are inspected
at every stage, which is why we proudly receive
the standards of RoHS and REACH, thus making us
the most reliable and genuine toroidal
transformer manufacturers in India!