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Watermist fire fighting MV electrical safety

I am reviewing the fixed watermist fire fighting installations in a new fleet of hybrid ships we are building . The water mist based fixed fire fighting appliances (FFFA) we are using extends into the main propulsion areas as well as the power generating areas.

Water Mist heads are used instead of sprinklers these days as these are more effective, however I can find no definitive tests or regulations that state water mist is safe to use in Medium Voltage switchboard areas?  Appreciate that if I have a fire the main objective is to extinguish it but it is not unusual for FFFA to be set off accidentally in a technical space so I must then consider IP ratings of equipments in these spaces in order that equipment is not damaged during an accidental discharge and that engineers investigating the incident are not at risk of electrocution from the MV systems which may still be live or charged!

Does anyone have any reference information regarding any testing done on Watermist systems to validate their safety levels with LV, MV and indeed HV systems?

Parents
  • Its the accidental discharge that causes the issues. I've had numerous accidental discharges via manual activation points for the hi fog as well as 2 smoke and 1 flame going off…..engineers LED torches are a source of activation as well….We are looking at dry pipe and glass bulbs as well as 2 smoke and 1 flame to help avert false alarm damage. We use this on the bridge and nav/comms equipment rooms so will be extending this to the propulsion rooms as well to cover the propulsion TX, VFD's and POD equipments. Class will accept IP32 in locked spaces  as  opposed to the main engine room space which of course is an issue if the WM goes off accidentally….and it will!  I'm also looking at mitigation of the IP32 cabinets…spray hoods and secondary doors to help limit any damage in the event of…..

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  • Its the accidental discharge that causes the issues. I've had numerous accidental discharges via manual activation points for the hi fog as well as 2 smoke and 1 flame going off…..engineers LED torches are a source of activation as well….We are looking at dry pipe and glass bulbs as well as 2 smoke and 1 flame to help avert false alarm damage. We use this on the bridge and nav/comms equipment rooms so will be extending this to the propulsion rooms as well to cover the propulsion TX, VFD's and POD equipments. Class will accept IP32 in locked spaces  as  opposed to the main engine room space which of course is an issue if the WM goes off accidentally….and it will!  I'm also looking at mitigation of the IP32 cabinets…spray hoods and secondary doors to help limit any damage in the event of…..

Children
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