Explosion Proof Wiring Systems

[pepparz]

Not asking to prove yourself just the regs so can have a quick look to satisfy curiosity

the reg is BS EN60079 series. does that satisfy you on this sunny saturday?

 

[pepparz]

I did my gas training at the Safety in Mines Research Facility. A fantastic place, explosions galore!

The test rig for testing motors is fun, they have a motor with an over large flame path. Quite spectacular when the surrounding atmosphere is at just below to upper explosive limit.

is that near area 51 in nevada?

 

[SPARTYKUS]

is that near area 51 in nevada?

I wouldn't know, I am actually a heavy goods train driver, I appear to have registered on the wrong forum. Damn this predictive text !

 

[pepparz]

I wouldn't know, I am actually a heavy goods train driver, I appear to have registered on the wrong forum. Damn this predictive text !

Hahaha nice one.

 

[D Skelton]

after having time to reflect on my posts ive decided to apologise to D Skelton, sorry mate it was wrong and unfair of me to mock and name call, hope you will accept this and think no ill of me.

Thank you, apology accepted.

 

[Engineer54]

ill just add this, the gap does not occur during a explosion its always there and it is measured with feeler gauges. just remember to use a silicon based grease to prevent the flamepath from rusting.

Well it is and it isn't...lol!! Machined flat faces without seals or gaskets will always have a gap. As far as i remember the limit on any such gap on flameproof flanges and the like is around a max 0.004'' depending on the type of gas/vapours involved. You measure any such gap in accordance with manufacturers recommendations to ensure that the gap does not exceed specification after the flange bolts have been correctly torqued down.

In the event of an internal explosion, the internal pressure created, will in it's own right expand any such gap, but still within the tolerances of it's type testing....


Things may have changed a little these days, as now i understand that Aluminium flanged enclosures are now often used in division 1 / Zone 1 - 0 and Ex 'd' equivalents. I've only ever used the heavy cast iron type enclosures!!

BTW, you didn't mention what method of IR testing you use at your site??

 

[Des 56]

The magic of air filled flameproof enclosures has now been revealed to the masses by pepparz in this thread
I am at a loss why he felt the need,some have worked in the mines most of their lives and didn't feel that urge
Was it something someone said?

and
Part 2 will now take the form of intrinsic safety and the use of the intrinsically safe Metrohm

Away to go then lad
This will be for the non explosive members benefit and general forum educational purposes perhaps

Next term oil filled switchgear as flameproof enclosures,a concise history

 

[Knobhead]

I'm dropping out of this before I blow a gasket!

Sorry a 0.005" FLP flange.

0.004" Min 0.006" max.

 

[Darkwood]

I remember when i had a customer where they filled gas bottles from nitrogen to oxygen thus the site was no Mobile Phones .... bring me in with a intrinsically safe mobile and see all the management start flapping because i answered my phone while working on a motor next to a oxygen filling tank.... they had never heard of a safe phone for use ...even got funny looks in tesco petrol station and when i said its intrinsically safe she said whats that mean .... told her and she went UH! i have to follow rules .... told her its a shame when your guidelines and your boss are so ill educated ....makes you wander exactly what they get payed for!

Went into have a chat with manager of local tesco's branch a week later and still they stuck to policy ... i left saying i thought you was a manager with discretion at your will.... seems you just another puppet not allowed to think for yourself.... he didn't like that at all ... i still get daggers when i see him lol .... hasn't stopped me using the phone though sometimes i do it on purpose cos im evil like that

 

[pepparz]

ah yes the oxymoron that is the intrinsically safe tester. i would personally IR in the conventionally way in the safe area,but if you need to do it in zones 2 or 1 on the kit make sure you do a gas test and have a hotwork permit.
pit electricians, ah the ones who when ty wrapping swa above ground still leave large drip loops between every ty.

 

[Engineer54]

ah yes the oxymoron that is the intrinsically safe tester. i would personally IR in the conventionally way in the safe area,but if you need to do it in zones 2 or 1 on the kit make sure you do a gas test and have a hotwork permit.
pit electricians, ah the ones who when ty wrapping swa above ground still leave large drip loops between every ty.

Actually this was a genuine question, seeing as you were/are working in a Hazardous Div 1 Zone 1
enviroment. The reason i asked, is that the old universal standard ''Intrinsically Safe'' Metrohm (that i still own) is no longer classified as intrinsically safe, and so no longer allowed on European EX 'd' sites. Soooo, i was wondering what has the Metrohm IR tester been replaced by, when needing to conduct IR tests in such hazardous areas??


I will hasten to add, that i still use my Metrohm intrinsically safe in such areas, as i have always done for the last 30 odd years, ...and with no detrimental effects whatsoever!! I also believe they are still sold by the present manufacturer for use within hazardous areas outside of the EU. That's Europe for you!! lol!!

 

[pepparz]

Actually this was a genuine question, seeing as you were/are working in a Hazardous Div 1 Zone 1
enviroment. The reason i asked, is that the old universal standard ''Intrinsically Safe'' Metrohm (that i still own) is no longer classified as intrinsically safe, and so no longer allowed on European EX 'd' sites. Soooo, i was wondering what has the Metrohm IR tester been replaced by, when needing to conduct IR tests in such hazardous areas??


I will hasten to add, that i still use my Metrohm intrinsically safe in such areas, as i have always done for the last 30 odd years, ...and with no detrimental effects whatsoever!! I also believe they are still sold by the present manufacturer for use within hazardous areas outside of the EU. That's Europe for you!! lol!!

no idea what theyve been replaced with. u can use what ever IR machine u want so long as u do a gas test to prove no flammable atmosphere exists. this is of course a continual gas test. but i just do it in the safe area and test the whole circuit with lids ON.very rarely have i had to IR in zoned area

 

[D Skelton]

Quite the little battle going on here, still, I think it could be more epic! Pepparz, for a bit of all out war why don't you ask Eng about 3/8" unthreaded earth rods, I know he loves talking about them!

 

[High Tower]

Quite the little battle going on here, still, I think it could be more epic! Pepparz, for a bit of all out war why don't you ask Eng about 3/8" unthreaded earth rods, I know he loves talking about them!

Don't u dare!!, you will be telling him to ask about exporting PME's next.................

For the love of god, do not poke the bear lol

 

[Clive P]

Hi,

Continuing on from E54's post ref the Intrinsically safe Metrohm; yes I still have mine too.
If I remember rightly this was deemed not suitable for use in the UK when the regs were updated due to the fact that it had to produce a test current of greater than 1mA ( if memory serves me right ) and we had to revert to the standard tester ensuring we carried out an atmosphere test before use. All of our resistance tests carried out with an Intrinsically safe Multimeter.
There was also something about dissipating stored energy, which I believe the Metrohm also catered for, ie, testing MICC where you needed to discharge the stored energy as the cable acts like a capacitor.
As E54 says , you can still buy this Instrument, but it is now called a Safety tester.

Regards.

 

[Engineer54]

Hi,

Continuing on from E54's post ref the Intrinsically safe Metrohm; yes I still have mine too.
If I remember rightly this was deemed not suitable for use in the UK when the regs were updated due to the fact that it had to produce a test current of greater than 1mA ( if memory serves me right ) and we had to revert to the standard tester ensuring we carried out an atmosphere test before use. All of our resistance tests carried out with an Intrinsically safe Multimeter.
There was also something about dissipating stored energy, which I believe the Metrohm also catered for, ie, testing MICC where you needed to discharge the stored energy as the cable acts like a capacitor.
As E54 says , you can still buy this Instrument, but it is now called a Safety tester.

Regards.

Had to have a chuckle about using standard IR testers in hazardous installations. There was a time when you would have been booted off the site and banned from ever returning if found using one!!

Outside of Europe, i've found the Metrohm is still the standard issue to maintenance electricians on such installation sites... Hard to believe a standard IR tester can be used in O Zones, as it is deemed to be a continuously hazardous zone, ...or used to be!! lol!!

 

[Des 56]

It says it all when practices that have stood the test of time are put aside for H+S drivel

 

[SPARTYKUS]

H+S drivel gone mad - an example - used to work on a huge site (Gas Board), had a bar on site n' everything, well it also had a heated outdoor pool.

back in the nineties I turned up one day with my cossie and popped down at lunch time to it, all gated up so went back to the jobsworth and asked "whats happened to the outdoor pool?"

"filled it in and slabbed over it"

me: "er, why?"

Jobsworth: "dangerous. Someone might drown"

I nearly passed out from the miasma of stupidity in the air

 

[Brightspark2]

H+S drivel gone mad - an example - used to work on a huge site (Gas Board), had a bar on site n' everything, well it also had a heated outdoor pool.

back in the nineties I turned up one day with my cossie and popped down at lunch time to it, all gated up so went back to the jobsworth and asked "whats happened to the outdoor pool?"

"filled it in and slabbed over it"

me: "er, why?"

Jobsworth: "dangerous. Someone might drown"

I nearly passed out from the miasma of stupidity in the air

Ha ha stood there in your flip flops, speedo's and towel...ha ha

Question is do you still own the Speedo's? Lol

 

[SPARTYKUS]

Ha ha stood there in your flip flops, speedo's and towel...ha ha

Question is do you still own the Speedo's? Lol

yeah but can only get one leg in them now