Pressure Relief Devices are designed to activate in the event of a build up of pressure within a shower unit - usually caused by a blocked shower head, blocked/ twisted or kinked hose.
Although the shower does contain various electrical components and wires when the PRD operates the water will be directed out of the unit safely via with a small tube or channel within the product and providing that the unit has been installed correctly and in accordance with manufacturers instructions should not cause any danger to the unit or user
I hope this information is of help.
Regards,
Karl
TRITON TECHNICAL TEAM
TRITON TECHNICAL TEAM, September 2010