how to find what is tripping fuse?

[electronicsuk]

There can't be many explanations. Either the fan is faulty, there's a loose connection that has been the cause of the previous short circuit, or you've damaged one of the cores by flexing it too much.

 

[sparkwright]

Perhaps you have snagged a wire with the fan casing, or a fixing screw somewhere.

 

[webbo1]

i havent screwed anythin new in since it was working, possible could have caught it on the casing but that would trip the fuse though wouldnt it?

 

[sparkwright]

i havent screwed anythin new in since it was working, possible could have caught it on the casing but that would trip the fuse though wouldnt it?

It did though, didn't it?

Check condition of all wires for any damage.

Sometimes a tiny short can take a while to come to light, and with the vibration of the fan, and you taking the fan apart, the fault can be disturbed.

PHOTOS.

 

[webbo1]

this is what completley baffles me, it was tripping the circuit then i took of the casing took a look at the wires everything looked fine so i turned it on again and the fan worked, so i put the casing back on and ever since then when i switch on the switch it not tripping the circuit but the fan will not turn on. i will upload some pictures

 

[webbo1]

heres the pictures. let me know what you think

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• webbo1
• 6 Jun 2010
• 1

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• webbo1
• 6 Jun 2010
• 1

Untitled

• webbo1
• 6 Jun 2010
• 1

Untitled

• webbo1
• 6 Jun 2010
• 1

Untitled

• webbo1
• 6 Jun 2010
• 1

 

[sparkwright]

For a start those wires pass through that metal mounting bracket.

There is no grommet fitted so those wires will chafe on the sharp edges of that hole.

Look closely and you may see damage on the insulation which is causing a short.

 

[webbo1]

ok il inspect this closely tomorrow. so does a short not always trip the fuse?

 

[electronicsuk]

I think I can already see a nick in the live wire in the second photo. I think you really need to take more time with your cable preparation. Bend the individual cores into shape such that they will sit nicely inside the enclosure, rather than just stuffing the lid back on as tight as possible and hoping for the best.

 

[webbo1]

sorted it, i removed a few cable clips in the loft so i could feed more of the wire through, put some more protection around the wire coming throught the mounting plate and cut off the wire that was causing the short. thanks for all your help