A breakdown occurs when the mechanical or electrical components of certain power-consuming appliances stop functioning. Breakdowns occur on a predefined list of buildings, with an MTB of 13,680,000 ticks (3.8 years). Only buildings that are currently functioning can break down, while buildings that are flicked off or have insufficient power are safe.
A broken-down building will stop working, behaving as though it has been turned off. In addition, batteries lose any energy they had previously stored.
When a building breaks down, a colonist with the Construction work type must replace the broken component with a new one, which is consumed in the process. The job takes 1,000 ticks (16.67 secs), regardless of external factors like skill or global work speed.
A successful repair depends on the colonist's Repair Success Chance. Assuming average health, a colonist will achieve a 100% repair success rate at skill level 8 or higher. If the colonist fails to complete the repairs, either due to incompetence or injury, then the building will remain broken and the component will still be consumed.
Repairing will never require advanced components.
You should always keep some spare components in case some important building breaks down. This is overall a fairly rare occurance, but a cooler malfunctioning during a heat wave isn't a great time. If you are running out of components but don't need the building, then it might be best to not repair it.
Below is an exhaustive list of all buildings that can break down:
- Power generators: