Um curto-circuito queimou o cabo após uma sobrecarga.

Because Portuguese often uses an article where English might not.

Here, um curto-circuito means a short circuit. The indefinite article um is used because this is being introduced as one event or one cause, not a specific already-known short circuit.

• um = a / an for masculine nouns
• uma = a / an for feminine nouns

So:

• um curto-circuito = a short circuit
• uma sobrecarga = an overload

Because curto-circuito is a fixed compound noun in Portuguese. It is written with a hyphen in standard spelling.

It is made from:

• curto = short
• circuito = circuit

But once combined into the technical term, it becomes curto-circuito = short circuit.

Yes, curto-circuito is masculine, which is why it takes um.

You can tell from the article in the sentence:

• um curto-circuito

Also, many nouns ending in -o are masculine, though that is a pattern, not an absolute rule.

So:

• o curto-circuito
• um curto-circuito

Queimou is the pretérito perfeito (simple past) of queimar.

It means the action is viewed as completed:

• queimar = to burn
• queimou = burned / burnt

In this sentence, it refers to one completed event: the short circuit burned the cable.

This is different from an ongoing or habitual past action. For example, if the sentence were describing something in progress or background information, a different past tense might be used.

In electrical or technical contexts, queimar is very commonly used for equipment being damaged by heat, overload, or electrical failure.

So queimou o cabo can mean:

• literally burned the cable
• more naturally in context, burned out / damaged the cable

Portuguese uses queimar very naturally for devices, wires, fuses, motors, and similar components.

Examples:

• O fusível queimou. = The fuse blew / burned out.
• O motor queimou. = The motor burned out.

O cabo means the cable, so it refers to a specific cable, presumably one already known from context or one identifiable in the situation.

Compare:

• queimou o cabo = burned the cable
• queimou um cabo = burned a cable

Portuguese often uses the definite article very naturally when talking about a specific object involved in the event.

Here, cabo means cable.

This word can have other meanings in other contexts, such as:

• cape
• handle
• some military ranks, depending on context

But in a sentence about short circuits and overloads, cabo clearly means an electrical cable or wire.

Após means after.

It is correct and common, especially in:

• written language
• technical language
• formal contexts

In everyday speech, many speakers would more often say depois de.

So these are both possible:

• após uma sobrecarga
• depois de uma sobrecarga

The version with após sounds a bit more formal or technical, which suits this sentence well.

Because sobrecarga is being presented as a countable event: an overload.

So Portuguese uses the indefinite article:

• uma sobrecarga = an overload

Without the article, após sobrecarga would sound unnatural in normal general Portuguese.

Sobrecarga means overload.

It is formed from:

• sobre- = over-
• carga = load

In electrical contexts, it usually refers to excessive load in a circuit or system.

It is a feminine noun, which is why the sentence has:

• uma sobrecarga

You may also see it in other contexts, such as:

• sobrecarga de trabalho = work overload
• sobrecarga elétrica = electrical overload

The word order is straightforward:

Um curto-circuito | queimou | o cabo | após uma sobrecarga

That is:

• subject: Um curto-circuito
• verb: queimou
• object: o cabo
• time/sequence phrase: após uma sobrecarga

So it follows a normal subject + verb + object pattern, with the final phrase adding when or after what circumstance the event happened.

Yes. That is grammatically correct.

Moving the time phrase to the front changes the emphasis slightly:

• Um curto-circuito queimou o cabo após uma sobrecarga.
• Depois de uma sobrecarga, um curto-circuito queimou o cabo.

The meaning is basically the same. The second version highlights the sequence more strongly from the start.

A careful European Portuguese pronunciation would be approximately:

Um curto-circuito queimou o cabo após uma sobrecarga.

IPA: /ũ ˌkuɾtu siɾˈkitu kejˈmo u ˈkabu ɐˈpɔʃ ˈumɐ suβɾɨˈkaɾɡɐ/

A few helpful notes for Portugal Portuguese:

• um sounds nasal, roughly like oom with a nasal vowel
• queimou sounds roughly like kay-MOH
• após often ends with a sh-like sound in European Portuguese
• unstressed vowels are often reduced, more than in Brazilian Portuguese

A rough learner-friendly version: Oong curto-circuito kay-MOH oo KAH-bo ah-POSH OO-mah suh-bruh-KAR-gah

Yes. Após clearly indicates sequence: something happened after the overload.

So the sentence presents this order:

1. uma sobrecarga happened
2. um curto-circuito burned the cable

However, real-world technical causation can be more complex. Grammatically, though, após simply tells you that the burning happened after the overload.

Yes, depending on nuance.

Possible alternatives include:

• danificou = damaged
• fundiu = blew / melted / fused
• estragou = damaged / ruined

But queimou is very natural in electrical contexts and often the most idiomatic choice.

For example:

• Um curto-circuito danificou o cabo = A short circuit damaged the cable.
• Um curto-circuito queimou o cabo = A short circuit burned/burned out the cable.

The original sentence sounds technical and natural.