Det kommer an på om effektfaktoren er høy.

Here det is a dummy subject, just like it in English It depends.

It does not refer to a specific thing. Norwegian main clauses normally need a subject, so det is used to fill that position in expressions like:

• Det kommer an på ... = It depends on ...
• Det er viktig ... = It is important ...

So in this sentence, det is grammatical rather than very concrete in meaning.

Kommer an på is the present-tense form of the expression å komme an på, which means to depend on.

So:

• å komme an på = to depend on
• kommer an på = depends on

This is a fixed expression, so it is best learned as one unit rather than word by word.

Because å komme an på is a multi-word verb expression.

In Norwegian, parts of this kind of expression are often split up when the verb is conjugated:

• infinitive: å komme an på
• present: kommer an på
• past: kom an på

So kommer is the finite verb, while an på stays later in the clause.

It looks odd at first, but it is completely normal.

• på belongs to the fixed expression komme an på
• om introduces the clause om effektfaktoren er høy

So the structure is:

Det kommer an på + om effektfaktoren er høy

In other words, på is part of the verb expression, and om starts the next clause.

Here om means whether.

That is the normal word to use after expressions like depends on when you are introducing a yes/no-type clause:

• Det kommer an på om ... = It depends on whether ...

By contrast, hvis usually means if in the sense of in the case that.

So:

• om = whether / if in indirect questions or uncertainty
• hvis = if for conditionals

In this sentence, om is the natural choice.

Because after om, you have a subordinate clause, and subordinate clauses normally keep the order:

subject + verb

So:

• om effektfaktoren er høy

If it were a direct question, the word order would be different:

• Er effektfaktoren høy? = Is the power factor high?

That is a very common difference in Norwegian:

• main clause/question: verb often comes early
• subordinate clause: subject usually comes before the verb

Because effektfaktoren is the definite form of the noun.

• en effektfaktor = a power factor
• effektfaktoren = the power factor

Norwegian often marks definiteness by adding an ending to the noun, instead of using a separate word like English the.

Here the sentence is talking about a specific power factor, so the definite form -en is used.

Because predicate adjectives in Norwegian agree with the noun.

Effektfaktoren is a common-gender singular noun, so the adjective takes the basic form:

• effektfaktoren er høy

Compare:

• common gender singular: en verdi er høy
• neuter singular: et nivå er høyt
• plural: verdiene er høye

So høy is correct because effektfaktoren is not a neuter noun.

Both kommer and er are in the present tense.

That is natural because the sentence states a general condition or general truth:

• kommer = depends
• er = is

Norwegian often uses the present tense just like English does in statements like:

• It depends on whether ...
• The answer is ...

So there is nothing unusual about the tense here.

Yes. That is a very good alternative.

• Det kommer an på om ...
• Det avhenger av om ...

Both mean roughly It depends on whether ...

The version with avhenger av is often felt to be a bit more formal or more neutral in technical writing, while kommer an på is very common in everyday language.

So both are correct, but kommer an på is especially useful to recognize because it is extremely common in speech and writing.