You need to ensure that you don’t overload your generator when it is in use.
Generators usually have a safety cut-out built-in (miniature circuit breaker); so an overload situation will simply flip the MCB out (like a resettable fuse) and the generator is not damaged. This however can be inconvenient if you are left in the dark, and you will be unable to reconnect your property to the generator until you resolve the overload situation – or else the MCB just flips out each time.
In this situation you’d need to identify which devices are likely to be causing the problem and manually turn them off at the main fuse board then try reconnecting the generator. The big consumers will be those things that heat or cool things. For example: the hot water cylinder, kettle, hob, aircon, air heaters etc. Once the generator is running and connected OK, you can try turning these things back on, one at a time to reduce the spike.
You have little control over the automatic devices (eg water pump, septic tank) but you can turn them off at the switchboard. Consider the load before turning on the semi-automatic or manual devices which you might want to use simultaneously. For example maybe don’t run the dishwasher at the same time as the kettle.
The worst case scenario is that an overload burns out some component inside the generator, such as the Automatic Voltage Regulator (AVR). These are replaceable, but not quickly and not at night when the shops are shut. If it burns out, you’d have to diagnose the issue, order a part and replace it. So its best not to overload your generator persistently.
Installing a generator that has sufficiently large capacity for your your needs works around this issue to some extent.