Bulb blowing

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I have a 40w incandescent bulb blowing in a cooker hood. A previous bulb was blown from the same location. After the bulb blew, a second bulb in the hood stopped working, same for the fan. Basically, the hood lost power after the bulb blowing. I am wondering if the bulb blowing caused the problem, or a problem in the hood wiring cause the bulb to blow? Can something external to the bulb cause the bulb to blow - power surge, short circuit, power drop because of load elsewhere?

Previously, I fixed it by taking the hood apart cleaning everything, dishwashed the motor, and it was working again. I did not check all the wiring connections.
 
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I have a 40w incandescent bulb blowing in a cooker hood. A previous bulb was blown from the same location. After the bulb blew, a second bulb in the hood stopped working, same for the fan. Basically, the hood lost power after the bulb blowing. I am wondering if the bulb blowing caused the problem, or a problem in the hood wiring cause the bulb to blow? Can something external to the bulb cause the bulb to blow - power surge, short circuit, power drop because of load elsewhere?

Previously, I fixed it by taking the hood apart cleaning everything, dishwashed the motor, and it was working again. I did not check all the wiring connections.
Sounds like it blew a fuse/tripped a breaker.
 
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I did not replace any fuse previously. I just washed everything and it was working. I don't recall if there was a fuse in the hood. The unit is plugged into a wall socket. I haven't yet checked if the fuse in the standard plug is blown yet.
 
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I am wondering if the bulb blowing caused the problem, or a problem in the hood wiring cause the bulb to blow?

A bulb 'blowing' can suffer a brief internal flash over, which can commonly trip MCB's and less often take out a fuse.

Basically, the hood lost power after the bulb blowing. I am wondering if the bulb blowing caused the problem, or a problem in the hood wiring cause the bulb to blow? Can something external to the bulb cause the bulb to blow - power surge, short circuit, power drop because of load elsewhere?

You are over thinking it - try simple fixes first.

Previously, I fixed it by taking the hood apart cleaning everything, dishwashed the motor, and it was working again. I did not check all the wiring connections.

That sounds a bit drastic and had potential to wreck the motor bearings. 'Previously' - you mean this has happened before? To be clear, it is fairly common for incandescent lamps when they fail, to flash over internally and trip MCB's Simply replace the lamp and reset the MCB.

Better, is to replace the incandescent lamp with an LED replacement as these tend to last much longer, use less power and tend not trip the MCB when they do fail.
 
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The bulb failed after 6 months or so. Although it wasn't a new bulb. Still, the blowing seems excessive. You can't ruin a sleeve bearing by washing. I have LED bulbs arriving from china just now and hence noticed the old one blown. It wasn't my hood, but the user did not complain.
 
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The bulb failed after 6 months or so. Although it wasn't a new bulb. Still, the blowing seems excessive.

We suffered a series of blown oven lamps, with the replacements not lasting long, just a few weeks. They were bought from an ebay seller, sold as suitable for 240v, but actually marked when they arrived 230v, but probably more suited to 220v. Once replaced with proper 240v versions they have survived years so far.

You can't ruin a sleeve bearing by washing.

Not ruin it as easily as a ball bearing, but none the less it will flush out the lube which is soaked into the sleeve.
 
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We suffered a series of blown oven lamps, with the replacements not lasting long, just a few weeks. They were bought from an ebay seller,
same happened
my elderly neighbour purchased a load of bulbs and was having them blow and asked me what i thought/help as she was going to get an electrician in to re-wire the place
I said hold on , her son had purchased a job lot, - and i put one in my house and it lasted a week, so she through those out - got replacements and was fine ever since
 
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same happened
my elderly neighbour purchased a load of bulbs and was having them blow and asked me what i thought/help as she was going to get an electrician in to re-wire the place

All a result of the 'harmonisation'. The number changed, without the actual voltage in the UK changing and the none technical just assumed EU 230v lamps were now fine to also use in the UK. I got into a habit of checking the actual voltage marked on the lamps.
 
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Found the 5A fuse on the standard plug blown. Replacing that fixed it. The plug supplied 2x 40W bulb plus the fan. Was 5A adequate for that? The hood label said 205W, which suggested less than 1A draw.

The bulbs were replaced with 2x 12W LEDs.
 
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Found the 5A fuse on the standard plug blown. Replacing that fixed it. The plug supplied 2x 40W plus the fan. Was 5A adequate for that? The hood label said 205W.

The bulbs were replaced with 2x 12W LEDs.

5amps is more than adequate. Likely the bulb flashing over internally, took the original fuse out with it.
 
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Would a flash result in an infinite draw, in other words it would have made no difference if the fuse was 13A?
 
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Would a flash result in an infinite draw, in other words it would have made no difference if the fuse was 13A?
Obviously not literally infinite, but it could be very high (and very brief), possibly high enough to blow a 13A fuse (or even a higher rated one, if such was available).

As Harry has implied, the duration of very high currents when a bulb blows is often too short to blow a fuse, whereas much more common to triop an MCB, but even fuses sometimes do blow in that situation.

Kind Regards, John
 
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Would a flash result in an infinite draw, in other words it would have made no difference if the fuse was 13A?

The 'draw' depends on the impedance of the supply. Imagine instead of cables, pipes. The smaller the pipe, the higher the impedance to limit the maximum which can flow through it.

Fuses have a graph of time versus current, which at it's maximum is limited by the impedance of the supply. The higher the current overload, the quicker they over heat and 'blow'. A 13amp fuse does not blow immediately you exceed 13amp, they will even support 20amp for quite a while. On the other hand, MCB's react much more precisely and tend to react quicker than simple fuses to overloads. Which explains why you often find a 32amp ring main MCB has tripped, where the 13amp cartridge fuse in a plug, protecting a faulty appliance has survived.
 
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A 13amp fuse does not blow immediately you exceed 13amp, they will even support 20amp for quite a while.
Indeed. In fact, as we've often discussed, a 13A BS1362 fuse will support something like 22A continuously and indefinitely without blowing - so rather more than "quite a while" :)

Mind you, even a hypothetical 13A MCB could take up to an hour ("quite a while") to trip with a current of 18.85A (13A x 1.45).

Kind Regards, John
 

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