cooker and fume extract

pdiddy

"I got a bad shock last year.

A bulb had blown in my cooker hood and the glass had shattered but the base of bulb was firmly screwed into the socket. I grabbed a pair of metal tweezers (I know, I know), made sure to switch the cooker off at the wall, and tried to get it out. I got thrown halfway across my kitchen. I had the chest tightning etc and also a very odd sensation in my thumb for months afterwards.


Did you notice that I switched the cooker off at the wall first? The switch for the cooker hood was up near the ceiling, unknown to me.

I've never felt so stupid in my life."

Just after reading this over in afterhours on a thread about people getting shocks and it got me wondering if maybe the fumehood should maybe have a isolating switch beside the cooker switch or maybe incorporated into the cooker supply and switch instead of being fed from a socket/spur behind the hood.

Now i know this lad went out of his way to get a shock using metal tweezers and not making sure power was off. But in my experience a lot of people see a switch beside something and assume the power must be off if that switch is off.

would be interested to hear other thoughts on this.

meercat

pdiddy wrote: »

Just after reading this over in afterhours on a thread about people getting shocks and it got me wondering if maybe the fumehood should maybe have a isolating switch beside the cooker switch or maybe incorporated into the cooker supply and switch instead of being fed from a socket/spur behind the hood.
.

new regulations state that all non accessible sockets should have a labelled isolator
this includes extractor fans,microwaves,washing machines etc

socket outlets that are not readily accessible must be provided with a clearly labelled double pole switch,rated 20amp,in an accessible position e.g. on the wall above the work top
(554.3.5)

pdiddy

I was actually thinking about that just after i posted, So with fridges,washers,dishwashers,dryers,cookers,extracts and microwaves having isolated switches the wall will be covered in d/p switches and normal general sockets.

I know the extract will have its own isolating switch but lets say over time the label falls or gets removed for whatever reason, The property is a rented property and the new tenants aren't aware that the switch is for the fan and assume the big cooker switch does the job and proceed to get a bang from extract.

what im trying to get at is should the cooker isolating switch isolate all items to do with the cooker and hob including the extract

meercat

pdiddy wrote: »

what im trying to get at is should the cooker isolating switch isolate all items to do with the cooker and hob including the extract

cant really see the problem
the extractor fan should be fused at 13amp and be rcd protected

i think that an emergency stop button as per commercial kitchens might be a better way to go then all electrics can be isolated
however you can legislate all you want but someone somewhere will still stick a tweezers in something electrical

Bruthal

pdiddy wrote: »

what im trying to get at is should the cooker isolating switch isolate all items to do with the cooker and hob including the extract

Not really. They should have checked the extractor was off rather than just assume it should be because they switched off the cooker isolator.

If you switch off a cooker isolator, or any switch, dont assume anything, even about the cooker. Test before doing anything.

meercat

robbie7730 wrote: »

Not really. You should have checked the extractor was off rather than just assume it should be because you switched off the cooker isolator.

If you switch off a cooker isolator, or any switch, dont assume anything, even about the cooker. Test before doing anything.

dont think it was the op
he was just repeating something he read

however your point is valid
Always double check

M cebee

dunno about the e stop
ive seen it mentioned before

i think you'd still need the local isolators anyhow

meercat

M cebee wrote: »

dunno about the e stop
ive seen it mentioned before

i think you'd still need the local isolators anyhow

i probably mentioned it on this forum before in fairness
local isolators required for sure

Bruthal

meercat wrote: »

dont think it was the op
he was just repeating something he read

however your point is valid
Always double check

Yea im having trouble reading lately:D

deandean

Aah now I don't think there's a need for an e-stop on a domestic cooker hood.

OP, after you've isolated something, always turn it on & off again to ensure it's off.

And look out for a set of insulated pliers in Lidaldi!

P.S. Worst shock I heard of was a DIY-er pal of my dad's who was making up a mains flex with a plug, for a lamp. He connected the plug. He stripped the two ends of the wires for the lamp and held them between his lips while he plugged in the plug to see if the lead was gonna be long enough :eek::eek: True story!

pdiddy

Don't worry robbie I've learned the hard way to make sure the power is off and not trusting a phase tester either only with multimeter and even then id be wary of touching a live conductor


Another question I've been wondering about (i'm on fire tonight)

with a domestic gas boiler should there be gas detection with a slam shut valve fitted

I'm currently living in an apartment with a gas boiler but no form of gas detection or shut off valve. The valve for shutting the supply is outside in a meter box enclosure but its just a manual valve.

pdiddy

And look out for a set of insulated pliers in Lidaldi!

Dont think id trust these im sure there perfectly fine but id prefer Knipex myself

P.S. Worst shock I heard of was a DIY-er pal of my dad's who was making up a mains flex with a plug, for a lamp. He connected the plug. He stripped the two ends of the wires for the lamp and held them between his lips while he plugged in the plug to see if the lead was gonna be long enough :eek::eek: True story![/QUOTE]

That made me laugh all i can picture is the plug plugged in and the lad with the cables in his mouth and a bulb shining bright in his hand like you'd see in the movies

meercat

deandean wrote: »

Aah now I don't think there's a need for an e-stop on a domestic cooker hood.

i meant for the kitchen electrics as a whole

Bruthal

deandean wrote: »

Aah now I don't think there's a need for an e-stop on a domestic cooker hood.

It would be an emergency stop for the entire kitchen that meercat is talking about.

OP, after you've isolated something, always turn it on & off again to ensure it's off.

And look out for a set of insulated pliers in Lidaldi!

P.S. Worst shock I heard of was a DIY-er pal of my dad's who was making up a mains flex with a plug, for a lamp. He connected the plug. He stripped the two ends of the wires for the lamp and held them between his lips while he plugged in the plug to see if the lead was gonna be long enough :eek::eek: True story!

That would be a nasty shock, that area can perceive down to a volt or 2.

My best one was the secondary side of a commercial microwave oven transformer. 2.5kv horrendous bang off it I got. No 230v shock I got came anywhere near it, and ive tripped RCD`s a couple of times through them shocks.

Bruthal

meercat wrote: »

i meant for the kitchen electrics as a whole

Go away out of that, you meant a stop button for each item:D

meercat

robbie7730 wrote: »

Go away out of that, you meant a stop button for each item:D

if i could get paid for it;)

Bruthal

pdiddy wrote: »

And look out for a set of insulated pliers in Lidaldi!

Dont think id trust these im sure there perfectly fine but id prefer Knipex myself

The insulation on the aldi ones will be perfectly adequate.

Bruthal

meercat wrote: »

if i could get paid for it;)

Me too:D

2011

M cebee wrote: »

dunno about the e stop
ive seen it mentioned before

Activating an E-Stop should never never considered as a proper electrical isolation.

i think you'd still need the local isolators anyhow

Yes, you would.

Bruthal

2011 wrote: »

Activating an E-Stop should never never considered as a proper electrical isolation.

I dont think anyone here believes it does.

Bruthal

M cebee wrote: »

ya
pdiddy has a valid point re:isolation
not the first time someone's made this mistake

Even if the cooker isolator switched off the entire house, diy people will still make these mistakes.

2011

robbie7730 wrote: »

I dont think anyone here believes it does.

Really?

meercat wrote: »

i think that an emergency stop button as per commercial kitchens might be a better way to go then all electrics can be isolated

Bruthal

2011 wrote: »

Really?

No, I dont think he really believes that its a proper isolating method to be honest. It might have prevented the OP`s story from happening though.

This all came up about an electric shower here before. Switch and contactor instead of an isolator.

2011

robbie7730 wrote: »

No, I dont think he really believes that to be honest.

It may be no harm to point out that activating an E-Stop is not considered a proper electrical isolation. Some people reading that post may not have your ability to know that what is stated is incorrect and is not what the poster truly believes.

Bruthal

2011 wrote: »

It may be no harm to point out that activating an E-Stop is not considered a proper electrical isolation.

No, none at all.

I debated it out here before myself, in the shower scenario. Switches and contactors instead of isolators because isolators were failing regular. Not proper isolation was my view on that.

Some people reading that post may not have your ability to know that what is stated is incorrect and is not what the poster truly believes.

Maybe he does feel it is a proper isolation method, I would be surprised though.

They are there in kitchens etc as an emergency shut down, not for electrical isolation anyway.

M cebee

robbie7730 wrote: »

Even if the cooker isolator switched off the entire house, diy people will still make these mistakes.

not the best idea tweezers

Bruthal

M cebee wrote: »

not the best idea tweezers

No, unless knipex bring out a set

2011

robbie7730 wrote: »

Switches and contactors instead of isolators because isolators were failing regular. Not proper isolation was my view on that.

I am working in a pharmaceutical plant at the moment. The LOTO procedure is very strict.

To isolate a motor the following SOP (which is typical for many pharma plants now) must be followed:

1) Starter racked out in MCC.

2) Fuses removed.

3) Drive locked out (padlocked by the electrician) so that it can not be racked in. A padlock is installed on the drive by each person that could be affected by the motor switching on (via a multi-clasp). Each person retains the key for their own lock. In some cases we may have 20 locks on a single motor, such as an agitator.

4) Signed LOTO tag placed on the drive.

5) Electrician "tries" to start the motor to ensure that it will not start.

6) Isolation verified by the electrician each day before work commences. Once verified the electrician signs the Safe Work Permit (SWP). The SWP can not become valid until all isolation signatures (mechanical & electrical) are in place.

"Full GMP procedure, no compromises, no excuses"

Bruthal

2011 wrote: »

I am working in a pharmaceutical plant at the moment. The LOTO procedure is very strict.

To isolate a motor the following SOP (which is typical for many pharma plants now) must be followed:

1) Starter racked out in MCC.

2) Fuses removed.

3) Drive locked out (padlocked by the electrician) so that it can not be racked in. A padlock is installed on the drive by each person that could be affected by the motor switching on (via a multi-clasp). Each person retains the key for their own lock. In some cases we may have 20 locks on a single motor, such as an agitator.

4) Signed LOTO tag placed on the drive.

5) Electrician "tries" to start the motor to ensure that it will not start.

6) Isolation verified by the electrician each day before work commences. Once verified the electrician signs the Safe Work Permit (SWP). The SWP can not become valid until all isolation signatures (mechanical & electrical) are in place.

"Full GMP procedure, no compromises, no excuses"

Then get the tweezers out

2011

robbie7730 wrote: »

Then get the tweezers out

:D

deandean

My favourite motor isolation: a big red plug & socket where the isolator normally is. Pull the plug and you can see it as you are working on the motor. That is safe. I dont think this procedure is compatible with LOTO though?

Bruthal

deandean wrote: »

My favourite motor isolation: a big red plug & socket where the isolator normally is. Pull the plug and you can see it as you are working on the motor. That is safe. I dont think this procedure is compatible with LOTO though?

It is, as the supply to the socket can be locked and tagged out, but its preferable to be able to lock and tag the local isolation out as well.

We probably wouldnt see too many industrial situations where a fixed motor has a plug and lead anyway.