Ex n UPS Systems

The ATEX & IECEx certified Ex n UPS system is a standard product designed for use in Zone 2 pressurised rooms. It comprises an Ex nA battery unit (type SBCE-1535), combined with an Ex d battery isolation contactor enclosure and a converted industrial UPS without batteries (inverter).

System Safety Philosophy

The safety philosophy of the system operates as follows:

The UPS monitors two shutdown conditions, loss of pressure shutdown (detected as a loss of mains supply to the UPS) and high-level gas alarm (signalled via a volt-free contact from a CPFG panel).

Two timers within the UPS control the sequence and timing of battery isolation. After any shutdown event, the cabin must be fully purged and pressurised before the UPS can be re-energised.

In the event of a sustained loss of pressure, all Non-Ex equipment in the cabin is shut down after a pre-set time delay, with the exception of the UPS and its load.
The UPS remains energised for the duration of the adjustable loss-of-pressure timer — typically 30 minutes.

In the event of a high level gas alarm, all Non-Ex equipment in the cabin is shut down immediately, again with the exception of the UPS and its load.
The UPS remains energised for the duration of the adjustable high-level gas alarm timer — typically 30 seconds, allowing connected systems (such as computers) to perform a controlled shutdown.

This product is compliant with DNVGL-ST-E272 and Hydrogen (H₂ certified).