What is deemed an explosive location?

[Dave A]

We've been ask to do a test for electrical compliance on a bakery. Is a bakery deemed an explosive location?

[wynn]

Flour dust 'very unstable'

[bergie]

i have never seen a hazardous area in a bakery. the flour dust is only a problem in larger quantities,such as a silo.

[murdock]

dave just to cover yourself...write a letter/email to the customer requesting information of any classified areas...he must respond with details of any classified areas if any...if he response and tells you there are no classified areas you can go ahead with a standard coc.

it is not your responsibility to classfiy areas...it is the customers responsibity to inform you of any areas which are classified.

if you are concerned...let me know and we will quote you to assess the installation...but if i were you i would get the customer do it...its not cheap.

always be careful of this...there are lots of different factors which must be taken into consideration for classified areas...gasses...suspened dust...battery charging rooms...spray booths...etc...etc

some big factories have thier own refuel points...so to cover yourself when working in big factory/warehouse enviroments always check and make sure...this would break the bank if you get caught off guard.

always CYA.

[desA]

What is deemed an explosive location?

Die klein-huisie?

[daveob]

WARNING

[Dave A]

write a letter/email to the customer requesting information of any classified areas...he must respond with details of any classified areas if any...if he response and tells you there are no classified areas you can go ahead with a standard coc.

A special thanks for that, Murdock. What I really like is it's a really sweet, generic way to deal with any enquiry that might have issues along those lines

[murdock]

i think if i tried it...i would get caught out because if the judge was smart he would tell me but you should have known better...being a master electrician...but in your case so long as your inspector is only an installation electrician he could say but how was i suppose to know and by gettin the customer to give it to you in writting you would have taken precaution...which will count in your favour.

the other thing you need to watch out for are flamable signs located in various locations...but it would still go back to the customer why didnt he notify you.

[Dave A]

I think the obvious stuff remains obvious. For example, if we did a panel beaters shop and signed off on the spray booth, I think we'd still be in for the high jump even if the owner signed off as there being no classified areas.

[AndyD]

Spray areas would be either zone1 or zone2

Bakery flour would be considered a class I dust

class I – dusts that ignite and propagate flame readily; the source of heat required for ignition being
small (in the case of an electric spark, 40 mJ being a normal value);

[Dave A]

class I – dusts that ignite and propagate flame readily;

Well, that's where flour gets interesting. Ordinarily it wouldn't qualify - you have to get a pretty specific air/dust mix before the magic happens.

The risk areas will generally be where it's being milled or moved and you end up with a suspension of fine flour in the air.

As it turned out in this instance, the flour is stored in bags in the storeroom (so we're not in a silo situation) and the only area where flour is poured dry is into the dough maker - and that certainly isn't producing the type of flour saturated atmosphere that would be cause for concern.

Now if we were talking gunpowder, different story.

[murdock]

as an installation electrician you are not required to know about regulations like a master elctrician...different spray booths spray booths would have diffrent areas classified...

as an example a closed spray booth with extraction sufficient to move the air at a certain quantity with safety valves on equipment etc would be different to a spray booth which is not entirely sealed...

some spray booths have flame proof fitting and othere have sealed glass and an outside cabinet which houses the fitting so the fitting is not always required to be a flame proof one....the motor for the extrctor fan might not be mounted inside the exhaust...so there is nothing stopping you as an installtion electrician signing off the installtion...you get the idea


my point is you need to understand the application and have the area classified by a certified person...which would not be your responsibilty.

my rule of thuimb is if you can smell it or see a haze or see signs indicating no smoking zones then beware.

if you are not a master electrician and you see a db which you need an allen key to remove the cover which has 30 bolts in it becareful...or long glnds which make the installtion just look like it was over speced becareful...

i would be interested to know what would happen in a case like this because much like a plumber connecting a geyser who doesnt have the correct qualification...he doesnt know any better...what if someone is hurt...

most people dont know the dangers of dust...nor do they know the dangers of the kitchen cupboard with all the different chemicals...so back to the customer if he runs a plant he should know the status and classifications of various areas.

something else i have just thought of is what happens if the paint is non flamable like a factory i worked in a little while ago...the spray booth is harmless because all the paints are water based...so back to the custmer again...how are you suppose to know...

i had another situation a while back where all standard fittings...plugs DBs etc where installed then along came the new tenant...he was using highly flamable solvents exposed...its not the electrician who did the installtions fault that nothing was rated...how was he suppose to know what they wer going to use the factory for...back to the customer or tenant in that case...we cant be held responsible for the negligence of other people.

i never put any specific specs because i am not aware of the application as a whole...something else i learnt from a very wise man

[Master Electrician]

Hi Dave,
Having worked in the milling and baking industry, I hope the following pointers will help.
Establish what is on the premises. Sectionalise it.
Flammable store. (Oil, paint, etc.) Hazardous Area
Fuel dispensing. Hazardous Area
Bulk offloading of flour from a tanker to a silo. Hazardous Area.
Bag store. Hazardous Area. In this case, all fittings need to be dust ignition proof.
A bakery is unlikely to generate sufficient quantities of dust to produce an explosive atmosphere.
However, be aware that the ovens operate at high temperatures.
Cables and equipment need to cope with this.
Adequate ventilation is required.
My 2c

[garthu]

At home......

When you have asked your wife sarcastically if the vacuum cleaner is working or not?