An emergency or standby power generator is classified as a separately derived system provided that its neutral is what?

An emergency or standby power generator is classified as a separately derived system when its neutral is separate from that of the normal supply. This separation is crucial because it ensures that the generator's electrical system operates independently from the utility power source.

When the neutral of the generator is separate, it effectively creates a distinct electrical system that has its own grounding and bonding connections. This is vital for safety, as it helps prevent parallel paths for current, which can lead to dangerous conditions and potential electrical faults. In a separately derived system, it is essential to properly ground the generator to ensure that any faults are cleared safely and do not affect the utility supply or other connected systems.

By keeping the neutral separate, the system can also help in managing fault currents and provides enhanced protection for both the operation of the generator and the equipment powered by it. This classification is particularly important for compliance with electrical codes and guidelines focused on safety and reliability in emergency power systems.