Diesel generators with different operating modes may have different system designs. For example, a generator running in parallel with the mains will require synchronizing equipment, such as an advanced control module and a fully automatic circuit breaker.
Generators running on standby normally require a load switching system, such as a manual or automatic transfer switch, ensuring that the power from the generator is safely isolated from the Mains supply. Generators running in standby are often ESP rated, but other generator ISO ratings can also be used.
Generators running in island mode are often the most basic and can run with little additional equipment. Common extra include bulk fuel tanks to allow for long periods of unattended running. These generators are often continuous power rated or prime power rated, depending on the load requirements.