I don't see where it says anything about having both L/N fused. It is a standard DP 3Amp FCU which means the fuse runs across the line.
Bathroom Fan Wiring
- Thread starter Lincol
- Start date
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Well, the very poor wording "double pole fuse" certainly implies that, doesn't it?
I'm sure that we'd all agree that that is what it is meant to be. However, with 'lines' in both L&N paths extending between two 'squares', coupled with the wording "double pole fuse", it could certainly be taken to mean that both L and N were fused, couldn't it? Fortunately, however, anyone confused by these very-poorly-written MIs would fail miserably in any attempts to buy a "DP-fused" FCU!
Kind Regards, John
Well of course we all know that what's needed there is a double-pole switch and a fuse in L. But what it says is "3 amp double pole fuse". And what the figure shows is symmetrical in L and N. Do you see a fuse in the figure? I.e do you think that the horizontal line between two small squares to the left of the switch is a fuse? If that's supposed to depict a fuse then it's depicting a fuse in both L and N. If it's not a fuse, then there are no fuses.
(I'm not trying to make a big deal of this; I jut mentioned it in the context of the up-thread discussion of following manufacturers' instructions and 99% of bathroom fans not having a 3A fuse.)
(I'm not trying to make a big deal of this; I jut mentioned it in the context of the up-thread discussion of following manufacturers' instructions and 99% of bathroom fans not having a 3A fuse.)
The Manrose version of that particular fan has a thermal device built into the windings - once blown it stays that way and the fan doesn't run. I took a defective one to pieces to find that out 
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As I just wrote (perhaps whilst you were typing this), I agree. It is potentially misleading, albeit no-one would find an FCU with a fused N!
Kind Regards, John
Having a fuse in the neutral is obviously potentially dangerous, since if that (but not a fuse in the L) blows, the load remains live. A DP MCB is a different matter, since both poles inevitably get disconnected simultaneously - two fuses would be equivalent to having separate SP MCBs in L & N - which again would not be acceptable, for the same reason.
Kind Regards, John
My mistake I read the instructions and stopped at....
The installation must have an omnipolar switch
with a contact separation of at least 3mm. The
circuit must be protected by either a 3 Amp fuse
or suitable 3A MCB.
Ah - as endecotp said, and as you now presumably realise, one has to 'scroll to the end' to see the "very poor wording" and equally poor diagram!
Kind Regards, John
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