Looking for an advisor to our custom Ring main product

[product_design]

Hi All, I noticed you have a thriving forum here and wanted to know if anyone here can help.

In short I am a design engineer, not an electrical eng or sparky. I have to design and prototype a display system that will incorporate a ring main. For reasons I cant go into outside a non disclosure agreement, the tricky part in the product is that a) the ring has to be approx 150 mtr long, b) support upto 60 sockets running devices like lazer projectors and lcd displays.

I figure there are 60 sockets and possibly 60 devices with consumptions in the range of 15 to 1.5 Amps
The system is essentially a snaking conduit with im presuming busbar inside.
I am looking for good sources of information and also when the project goes live an engineer to specify the electrical conductors, insulators and consumer units.

Your help is greatly appreciated.

Cheers

Chris

 

[dragon-av]

BEing a custom AV installer I can kind of see where your coming from but perhaps are looking at it all wrong a Socket is multiuse use device rated upto 13A, you need to find the current draw of your gear and work on that most like 3-10A per device MAX normal operating probably 0.5 to 3A YOu might be better off talking to some Pro lighting kit manufacturers about the regs and how they apply. Is this for fixed or mobile installation

 

[product_design]

Cheers for the post,
At this time the brief states the unit must have multi product compatibility. In short this system will be sold allowing various display items to be plugged in, so at this time its 60x 13A sockets.
You have raised a useful point and I will discuss this with the client, it could make things a lot easier if we bring the collective rating down, right?
It wont be mobile, as such it will be installed overhead in showrooms, effectively hanging from the ceiling.
Its an unusual product that has a special feature which is unseen by anything commercially available. But for simplicity, I wont go into that further.
initially I thought a company who install the mains to showrooms like a commet or what ever might be able to help with specking type of consumer units etc? Not my field so a bit lost
I wondered if here I could find out if it sounds feasible, I heard that ring mains are restricted by area and not length, is this to do with issues of RF interference, acting as an Ariel ect
you mention speak to pro lighting kit manufacturers, recommend any links etc?

 

[scotsparky]

well the ring area does affect the ring length a room 10mx10m room which is 100square metres with one ring round it is a 40m run of cable aprox so you ten get into the problems of volt drop and to allow for that you may have to put 2 ring in or a larger cable.
A 150m long ring is very large indeed and on a rough guess would need a large cable such as 6mm cables. which will push the price up. what i have seen in these situations is a busbar trunking at high level with sockets attached to it. its easy to install and with high frequency appliances like you mentioned will be able to allow for the high earth leackage currents produced.

 

[product_design]

Cheers again for the post.
Would you be able to send me a link on the web so I can get an idea of this busbar with sockets? is it like the attached? As I said I have no practical experience with this area. which manufacturer of busbar is worth noting. we may have to get samples etc Going to larger cable will be fine 6 mm or busbar, in fact it defo going to have to be busbar as the shape of the strip suits a key design aspect we have to intergrate. adding another ring is simply not an option, due to this hidden feature which really complicates things, its got to be 150mtr loop no breaks, idealy one consumer unit.
I ended up talking to contactum today and he did mention that I would end up with the ring at such a high rating i would need to step it down for each socket, but im confused by that. Consumer unit will trip if the 13A fuse goes, right?

For the likely loadings i put at the start of the thread, can folks suggest a suitable consumer unit as a rough guide. Also can anyone comment of the cost per mtr of lower rated busbar trunking + 60 sockets.

Also here's a nice dumb question for everyone; is a ringmain at 500A more hazardous than the standard domestic 32A. Its current that kills, isn't it, so its way more hazardous?? What safety limits apply to this product for use in public/ retail spaces etc?

 

[ian.settle1]

Cheers again for the post.
Would you be able to send me a link on the web so I can get an idea of this busbar with sockets? is it like the attached? As I said I have no practical experience with this area. which manufacturer of busbar is worth noting. we may have to get samples etc Going to larger cable will be fine 6 mm or busbar, in fact it defo going to have to be busbar as the shape of the strip suits a key design aspect we have to intergrate. adding another ring is simply not an option, due to this hidden feature which really complicates things, its got to be 150mtr loop no breaks, idealy one consumer unit.
I ended up talking to contactum today and he did mention that I would end up with the ring at such a high rating i would need to step it down for each socket, but im confused by that. Consumer unit will trip if the 13A fuse goes, right?

For the likely loadings i put at the start of the thread, can folks suggest a suitable consumer unit as a rough guide. Also can anyone comment of the cost per mtr of lower rated busbar trunking + 60 sockets.

Also here's a nice dumb question for everyone; is a ringmain at 500A more hazardous than the standard domestic 32A. Its current that kills, isn't it, so its way more hazardous?? What safety limits apply to this product for use in public/ retail spaces etc?

VERY MORE HAZARDOUS, think you had better get a qualified Electrical Engineer to help with the design of this idea before someone get seriously hurt.

 

[xraytek]

Here is a link for a PDF catalogue of the type of busbar systems I have come across in the past.
It is suspended from the ceiling and has tap off points at regular intervals for fused plug in modules.

Hope that helps

 

[product_design]

Cheers xray and Ian.
As thought Ian and dont worry it is going to have to get tested and cirtified before manufacture. Though we could fry someone nicely with the prototype if were not on the ball
So thats one of the reasons of this thread, I am looking for an electrical engineer we could employ regarding the design and have him sign it off as safe.

I will check out the pdf. cheers

 

[product_design]

So far I have got from this thread that, I can have a ring 150 meter long but could be bugged by Voltage drop, the solution is using thicker cable 6mm or busbar.

I would still like to know about appropriate consumer units ( ballpark is fine )
And wondered if anyone here would be qualified and experienced at working on distribution design, certified etc and available to work on short term contract?

 

[scotsparky]

the consumer unit requiered depends on the loading current requiered No of circuits ect . Merlin Gerin i use a lot as they are easily available and spares arnt a problem

Wheres the contract and what you after? i am interested but based in glasgow

 

[product_design]

Cheers Scots'

Well at the moment I dont have the figures other than 60x 13a sockets not much diversity though. some point above on likely loading. the equipment will be laser and led displays so i see ratings between 0.5 and 15 amps ( so might need some plugs at higher than13a) I need to work with an engineer who can help develop and sign of the design some of the design work we will produce in coordination. Im in bristol. But shouldnt be too much bother. If you have an email or mobile ill follow it up.

 

[not clever]

Cheers Scots'

Well at the moment I dont have the figures other than 60x 13a sockets not much diversity though. some point above on likely loading. the equipment will be laser and led displays so i see ratings between 0.5 and 15 amps ( so might need some plugs at higher than13a) I need to work with an engineer who can help develop and sign of the design some of the design work we will produce in coordination. Im in bristol. But shouldnt be too much bother. If you have an email or mobile ill follow it up.

you'll be looking at 32 or 16amp commando (BS EN.60309-2) sockets then.

 

[product_design]

One thing is clear it has to be one circuit only thats 150m long. So it would save a lot of hassle if your right and I can stick to lower ampage consumer unit and conductors. I really need to get this likely display equipment nailed down.

 

[scotsparky]

why does it have to be one circuit? 1 reason that Uk can use a ring ciruit is that the plugtops are fused therefore limiting load on that outlet if your using 16 or 32 a outlets then rings are doughtfull as the lead from appliance to plug has to be same as supply cable.

 

[product_design]

It has to be one circuit because of this bizarre feature. wait for it.... This system acts as a mobile track of sockets. imagine a ring combined with an overhead conveyor! this is the real challenge. those sockets have to move all the way along a 150m track and go round and around at 10m /min. crazy project huh? no idea if this has been done before, i guess I have seen similar on robotic manufacture lines. :s We are unfortuanatly going to have to use a track of live busbar or similar and feed the ring from a point that uses some rolling contact system! Anyone got advice on simmilar applications would help. so far I feel its out there on the dumb ideaometer!

 

[UNG]

I don't think this is a dumb idea and is only likely to fail due to available budget limitations. As you have expanded the brief through this thread I think what you are trying to achieve is possible but I would need to see a sketch of the rig you are trying to build to advise further