[Lancaster] OT : electrical installation

[andy baxter]

On 21/08/11 12:17, Simon Hobson wrote:
>
>>> Why not just buy a plug-in RCD (as used for lawn mowers)? They also 
>>> seem to be cheaper.
>>>
>>
>> This might do, but then there's always the temptation to unplug it 
>> just to solve some temporary problem, and forget to plug it back in. 
>> I think a socket would be better really.
>
> Absolutely right - it's the same as the way people treat a fuse 
> blowing as being a faulty fuse, often "solved" by fitting a larger 
> fuse so it doesn't blow. It would also be worth looking at the 
> distribution board - if it's using MCBs (Miniature Circuit Breakers) 
> then it may be possible to fit an RCBO (combined MCB and RDC) instead 
> which would give protection to the whole circuit. Most modern boards 
> have RCBOs available for them, it's mainly whether there's enough 
> space as they are significantly larger.

This would be a good solution if it's possible - I'll look into it.

> Actually, there is no regulation that *requires* PATs per se. The 
> various regs require that systems and procedures are in place to 
> ensure reasonable safety. PATs are only one part of this and according 
> to the course material from work, 90+% of faults are found by the 
> visual inspection. Also, if the device isn't portable then things 
> change again (that's the P in Portable Appliance Test).
>
> What it comes down to is, should something go wrong, can I stand up in 
> court and honestly say "I made reasonable provision for safety" ?
>
> I'd suggest ...
> Make sure everything is earthed properly - and it's tested. Fit a 
> backup over-temperature trip (manual reset) that will cut off the 
> heater if the software/hardware fails. Take account of the use of 
> water and the chances of it getting hosed down - consider fully sealed 
> enclosure, though that's non trivial to maintain once you start making 
> holes in it. The rest is mostly common sense.
>

Thanks. Obviously I'll take care to make sure things are as safe as 
possible. I'll look into getting a thermal cutoff. I think I'll also 
keep a log of all the safety checks I've done, just in case I ever need 
to prove I've been careful.

Thanks everyone for the advice.

andy