Advice on designing an electrostatic-proof building please.

[Mark42]

Did you buy the suit off the guy from Boney M?

No.
I sold him my spare one.

 

[pc1966]

Fun fact (well, not for him) is that Bobby Farrell died in St. Petersburg on the anniversary of Grigori Rasputin's death.

Oh those Russians...

 

[DPG]

Fun fact (well, not for him) is that Bobby Farrell died in St. Petersburg on the anniversary of Grigori Rasputin's death.

Oh those Russians...

Always a source of good information this forum.

 

[Mark42]

OK, that's enough reminiscing . I'm ordering trunking to use as dado rail today.

Unitrunk looked excellent, until I looked at the price: 100 x 50 x 3m is £193! I though it was a typo.

Very similar Tamlex 100 x 50 x 3m from CEF is £24.17.

I'd have to cut my own holes in the Tamlex, but for an overall saving of £1,012 (!) I think I'll get the jig saw out

 

[pc1966]

Unitrunk looked excellent, until I looked at the price: 100 x 50 x 3m is £193! I though it was a typo.

That is the list price. Most electrical trade places will give you discounts of the order of 70-90% on that if you ask the right folk.
[automerge]1596528738[/automerge]
If your company are doing a lot of this sort of work (internally, not as electrician services, etc) it might be in your interests to apply for a trade account with one or two of the local wholesalers.
[automerge]1596528945[/automerge]
Is the trunking just for a set of 13A sockets? you might find it easier to use the likes of these and glands/Flexishield between them:

MK Electric K2946ALM Metalclad Plus 2 Gang Double Pole Switchsocket With Surface Mounting Box 13A - Shop4 Electrical

Buy MK Electric K2946ALM Metalclad Plus 2 Gang Double Pole Switchsocket With Surface Mounting Box 13A. Shop today.

www.discount-electrical.co.uk

 

[KennyKen]

If you have explosive material or potential to become explosive then you’ll first need to follow Hazard area classification depending on what chemical or potentially explosive Material you are using. Normally cabling would Have to be intrinsically safe ie the use of shunt diodes or enclosures would have to be EX rated depending on the application. EX D is flameproof, EX P is pressurisation of an enclosure. EX E is extra protection and so on. Zoning is generally 0,1 and 2 and that basically goes on your LRL & URL limits.

 

[Mark42]

If you have explosive material or potential to become explosive then you’ll first need to follow Hazard area classification depending on what chemical or potentially explosive Material you are using. Normally cabling would Have to be intrinsically safe ie the use of shunt diodes or enclosures would have to be EX rated depending on the application. EX D is flameproof, EX P is pressurisation of an enclosure. EX E is extra protection and so on. Zoning is generally 0,1 and 2 and that basically goes on your LRL & URL limits.

Thanks for the ideas, but those regs are for explosive atmospheres, as often found in chem plants, or offshore. It has nothing to do with explosive substances. It's a very frequent confusion, especially among regulators.

Think about it - a sparky switch would definitely ignite a gas/air mixture permeating the whole area, but the same sparky switch would not jump across a room and set off a pile of nitrocellulose propellant sitting on a lab bench. It's only static protection which is important to consider in the latter case.
[automerge]1596533604[/automerge]

That is the list price. Most electrical trade places will give you discounts of the order of 70-90% ...

Yeah, it's stupid isn't it? Like arguing with Travis Perkins. We do have trade accounts and I'm good at getting best prices, but not many places advertise the Unitrunk stuff, so it's perhaps too much effort.

Update: I just checked, it appears Unitrunk only sell direct from their own places, and there's no central tel number, only published (massive) list prices and an email form. They appear to be one of those companies which makes it hard to buy from them. Marketing people call this having a 'customer prevention department' I can't be bothered! cf. Two clicks on CEF and Tamlex product can arrive tomorrow ...

Is the trunking just for a set of 13A sockets? ...

No, it's for power, data, telelphone and a DC lab supply as well. Hence the flexibility of using trunking.

 

[Julie.]

I take it that using nitrocellulose propellant, you are loading ammunition, anything interesting?

 

[Mark42]

I take it that using nitrocellulose propellant, you are loading ammunition, anything interesting?

Not exactly, but yes, interesting. Do you shoot? or maybe ex-forces?

 

[Julie.]

Not exactly, but yes, interesting. Do you shoot? or maybe ex-forces?

Yes I shoot, also section 5

 

[Mark42]

Yes I shoot, also section 5

S5 is rare, well done! Anyone who can deal with the Home Office and retain their sanity deserves respect .

 

[Julie.]

S5 is rare, well done! Anyone who can deal with the Home Office and retain their sanity deserves respect .

Scottish Government!

Also who said I retained my sanity?

 

[KennyKen]

Three types of Hazardous Areas are recognised as follows:
• Group II - Hazardous Areas (gas or vapour) in which an explosive atmosphere is present, or may be expected to be present, in quantities such as to require special precautions for the construction, installation and use of the equipment.
• Group III - Hazardous Area (dust) in which combustible dust in cloud form is, or can be expected to be present, in quantities such as to require special precautions for the construction and use of equipment in order to prevent ignition of an explosive dust/air mixture.
• Explosives Hazardous Areas – An area in which explosives material/substances of Explosives Ordnance are exposed to the atmosphere such that they require special precautions for the construction and use of equipment in order to prevent ignition of an explosives material/substance.

sound suspiciously like the material your working with... These rules don’t just apply to the Oil & Gas and offshore industries mate.

 

[pc1966]

Update: I just checked, it appears Unitrunk only sell direct from their own places, and there's no central tel number, only published (massive) list prices and an email form. They appear to be one of those companies which makes it hard to buy from them. Marketing

Some others also do socket fittings. You might have more luck with this:

Cable management - overhead | Legrand United Kingdom

www.legrand.co.uk

I found it easy to get the Unitrunk stuff from Holland House (oddly enough a Scottish electrical trade suppler, one of the oldest).

 

[Mark42]

Three types of Hazardous Areas are recognised as follows:
...
• Explosives Hazardous Areas – An area in which explosives material/substances of Explosives Ordnance are exposed to the atmosphere such that they require special precautions for the construction and use of equipment in order to prevent ignition of an explosives material/substance.

sound suspiciously like the material your working with... These rules don’t just apply to the Oil & Gas and offshore industries mate.

Eh? Where did that badly-written rubbish come from?

I've been working with this stuff for 40 years but have never read that before.

I can't believe that's from a UK or European document. Whichever genius wrote '... explosives material/substances of Explosives Ordnance are exposed to the atmosphere [sic] ...' clearly has no experience of working with energetics.

That is a fine example of exactly the kind of nonsense that gets into the literature, then is parroted by an enforcing authority without understanding. I'm not having a go at you, mate, but I've been dealing with this 'legislative' cr@p for decades and it irritates me

In the UK we have the HSW Act, and the subsidiary SI 2014 No. 1638 The Explosives Regulations 2014.

In essence they require you to take reasonable precautions, considering all the circumstances of each case. Therefore the requirements are very different if you wish to set up a nitroglycerine factory producing 1000 tonnes a year, and if you want to hold a few grams in an experimental lab for a day.

Excuse the rant, but essentially my policy is to identify actual risk (in this case static sparks) then to use common sense.

Only rarely do flames shoot out of 13A sockets. Or at least from those which I wired they don't.

So far

 

[KennyKen]

Well that’s straight from the compEX list of definitions. A standard used by every global Hazardous area company, and no offence I know which argument I would believe. OK. Your dealing with “Grams” irrespective of large factories. Your Duty of care is to ensure that your install ensures that the risk is ALARP. I wouldn’t be reliant on a 13amp B&Q socket for that.

 

[static zap]

..Do have a vague memory of an Electrostatic Field detector .. that would would wail with big field changes , down side was it used handpicked CMOS inputs
left in a ZAPABLE open circuit state + attached to paddle antennas ..
(but I'll have to trawl internet history from pre 1998 )
( Moving any midly conductive object in an electric field --Can add energy to its stored charge - An induction technique )
... capacitively detecting any charges moving about nearby .... assuming no strong AC fields upset it.
(any missing -r-s due to iffy keyboard.)

 

[Mark42]

Well that’s straight from the compEX list of definitions. A standard used by every global Hazardous area company, and no offence I know which argument I would believe. OK. Your dealing with “Grams” irrespective of large factories. Your Duty of care is to ensure that your install ensures that the risk is ALARP. I wouldn’t be reliant on a 13amp B&Q socket for that.

Oh well, I tend to believe the opinion of someone who’s actually worked with live explosives for 40 years and still has all appendages attached. Now where would I find one of them?

I’m interested by what mechanism you believe the presence of an empty and shuttered quality 13A metallic socket could cause the ignition of say 5g of nitrocellulose in a crucible a metre away. If there’s something I don’t know I genuinely want to learn. I’m a scientist by nature and training: the only thing a scientist knows for certain is that he or she doesn’t know much.

I accept that many guidelines are there to be idiot proof. Eg exclude sockets so no fool can plug in a soldering iron or fan heater. But I will be excluding not only static from my lab, but fools as well.

ps. What’s compEX? I’ve never heard of it.

 

[pc1966]

Oh well, I tend to believe the opinion of someone who’s actually worked with live explosives for 40 years and still has all appendages attached. Now where would I find one of them?

As Derek Lowe put it:

Hexanitro? Say what? I’d call for all the chemists who’ve ever worked with a hexanitro compound to raise their hands, but that might be assuming too much about the limb-to-chemist ratio.

I accept that many guidelines are there to be idiot proof. Eg exclude sockets so no fool can plug in a soldering iron or fan heater. But I will be excluding not only static from my lab, but fools as well.

That is a factor for this forum - what sort of load(s) are you planning?

To my untrained eye with explosives, keeping the opportunities for electrical incidents down is a starting point, and then taking steps to limit the worst-case let-through energy if there is a fault, the second step.

For example, if you have no loads above 5A or so, you might chose a few radial sockets with 10A MCBs for your "13A" sockets, and have the whole system backed up by, say, a 32A BS88 fuse as an ultimate energy-limiter compared to MCBs at high fault currents.

 

[Mark42]

Well that’s straight from the compEX list of definitions. A standard used by every global Hazardous area company, and no offence I know which argument I would believe. OK. Your dealing with “Grams” irrespective of large factories. Your Duty of care is to ensure that your install ensures that the risk is ALARP. I wouldn’t be reliant on a 13amp B&Q socket for that.

Tell you what though, I’d be with you when it comes to major storage magazines. I’ve just watched a video from Beirut today. That was one astounding bang, the shockwave created its own meteorological effect. I reckon that was tens, if not hundreds of tonnes of HE, all going off at once. Not ideal.