You can no longer post new replies to this discussion. If you have a question you can start a new discussion
Residential Sprinkler Pump Protection
Former Community Member
The British Standard for domestic sprinklers stipulates where a pump is required to boost the water pressure circuit breakers are not to be used for protection. On commercial installations we would have previously used a lockable red enclosure with main switch and MCB. Does anyone have any ideas on suitable solutions for the domestic sprinkler scenarios using a cartridge fuse or similar?
Others here will know better than me - but certainly the requirement for fuses rather than MCBs on fire safety circuits is a common one.
The solution will depends somewhat on the size of circuit - some manufacturers offer MCB-sized HBC fuse carriers which you could probably swap the MCB for - which might do you up to about 32A. Above that they tend to be supplied as ready assembled switch-fuses (sometimes with a DIN-rail mounted fuse holder - often 1.5 or 2 'modules' wide, sometimes something more bespoke). Larger DIN-rail fuse carriers are available separately, but you then tend to run into BS EN 61439 issues about becoming an assembly manufacturer and having to type test the completed assembly etc.
Fuses are very, very, reliable. MCBs are just very reliable - and in principle an MCB might have had a full current trip event in the past, and be in some way weakened, and you cannot tell from outside.
Generally the idea here is that the pumps are certain to keep turning right to the last possible moment. - if required that includes while the burning building pretty falls down around them.
Mike.
PS
DIN rail fuses are common enough - we just need UK CU manufacturers to be a bit less restrictive about stuff made by others in their enclosures magically making it unsafe.
On the continent Neozed and Diazed bottle fuse holders are often seen as part of a domestic DIN rail fuseboard - sometimes as the main incoming let-through energy limiting element.
Yes they can be removed without a tool, and the live contact which SHOULD be the base can then be touched.
In the UK they should therefore be in an enclosure that requires a key or tool to open.
One merit of such fuses is that an ES base lamp can be inserted in place of the fuse. If the lamp lights with all loads turned off, then there is a fault.
