CB级 ATS uses two circuit breakers as the switching element — it provides both switching and overcurrent/short-circuit protection in one unit. PC级 ATS uses a dedicated load break switch designed only for transfer — it switches faster (as low as 30ms) but requires separate upstream protection. Choose CB级 when you want integrated protection, and PC级 when you need ultra-fast switching and already have protection devices.

Transfer time depends on the ATS type and settings. CB级 ATS typically transfers in 0.5-2 seconds including the relay delay. PC级 ATS can transfer in as fast as 30-100 milliseconds. The controller also has an adjustable time delay (usually 0.5-5 seconds) to prevent nuisance transfers from brief voltage sags. For critical loads like data centers, we recommend PC级 with minimum delay settings.

Yes, the ATS controller continuously monitors both power sources. When mains power returns and stays stable for a configurable recovery delay (typically 30 seconds to 5 minutes), the ATS automatically transfers back to the normal source. This auto-retransfer feature can be disabled if you prefer manual re-transfer, for example to allow generator cooldown before switching back.

If both source 1 and source 2 are lost, the ATS will remain in its last position (or go to off, depending on the model) and output will be de-energized. The controller will continue monitoring both sources and automatically restore power as soon as either source returns. For 100% uptime requirements, we recommend pairing the ATS with an uninterruptible power supply (UPS) for ride-through during the transfer gap.

Yes, GOHO Electric offers optional commissioning services including on-site installation supervision, functional testing, transfer time verification, and operator training. Each unit is fully tested at the factory before shipping and includes a test report. On-site commissioning ensures the system operates correctly with your specific generator and utility connections.