10 MVA or 10,000 Kva Which is Bigger
There is an interesting difference in language between industrial electrical engineers and utility electrical power and transmission engineers. One area where this is most evident is their language for electrical power transformers, for MVA versus KVA. For example, their difference in quantitative perspective between a 10 MVA and a 10,000 Kva transformer.
Let’s say we are talking to an electrical utility power transmission engineer and refer to a 10,000 kva oil filled power transformer, say a Siemens or ABB. Their immediate tendency is to think of it as a small transformer, not too important. The tendency is based on language that includes Kva. They automatically think of Kva transformers as small. It has to be small because Kva is a small unit of capacity in their world. And they might assume the voltage must be only 15 kv, 25kv or 35 kv. Now if we were to switch to MVA and spoke of a 10 MVA oil filled power transformer, same size transformer, the utility engineer becomes engaged in the conversation, because now we’re talking their language. 10 Mva, 20 Mva, 100 Mva oil filled transformers, the stuff of real power. This is not a false bias. It is the language of their world and it makes sense to them.
If we switch our conversation to an industrial or manufacturing electrical power engineer, just the opposite is true. Let’s say we are talking to a plant electrical engineer and refer to a 10 MVA oil filled ABB or Siemens power transformer. Their immediate thought is that’s a big power transformer. And they would also have a tendency to think the voltage would be 115kv, 240kv. Some high voltage. If we were to change the language to a 10,000 kva Siemens transformer, they might think it’s just a pretty big unit for a large manufacturer. Not a big deal. This is still the language of bias. The way we think. It’s not wrong. It’s just the language we think in. And in each person’s world, it is correct.
In this example, we are talking about the same size transformer and having a little fun with the difference in perspective between the industrial world and the utility world.
In MIDWEST’s world we have to think in Kva and MVA. Where they may not be the same is the difference in voltages typically found with MVA versus those typically found with kva transformers. This is our bias. MVA is big voltage and Kva is little voltage. Usually, but of course these biases are not always true.