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Discuss Finally some common sense from a fan manufacturer? in the Electrical Forum area at ElectriciansForums.net

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Seen a few threads on here over the years so this might come in handy for someone.....wiring instructions state no need for local fuse if fed from 6a lighting circuit, Silent Extractor Fan | Greenwood Airvac SR100 Epicair.co.uk - https://www.epicair.co.uk/sr100.html
Have noticed the fans that don't need the 3A fuse are at the top end of the price range,like the ventaxia inline fan and the Greenwood 100m wall fan(£80).
But can make the install easier.
Regards,S
 

Baddegg

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Have noticed the fans that don't need the 3A fuse are at the top end of the price range,like the ventaxia inline fan and the Greenwood 100m wall fan(£80).
But can make the install easier.
Regards,S
That fan is £33 inc vat....
 
Surely the thermal link embedded in the windings will do a far better job at that than a 3A fuse?
I don't actually know but that is the purpose of the 3A fuse. I found a university study into this a while ago, can't find it now which found it to be highly unpredictable dependent on fan and/or fuse manufacturer.
 

Marvo

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I think most of the motors in domestic fans nowadays are covered as 'impedance protected' (ZP) as per UL 1004-2 requirements where they're less than 100 watts and their internal impedance is sufficient to prevent their temperature increasing above a certain point under a prolonged locked rotor condition. If so it's unlikely they'll have a thermal fuse on the windings.

A 3Amp fuse on the supply would only blow if there was complete winding insulation breakdown and a flash fault. I guess the thinking is that the internal wiring might be too small CSA to achieve a high enough fault current to achieve disconnection by the OCPD on the final circuit in the consumer unit.
 
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