Power Distribution, Advise sought

confused.com wrote: A few standard pieces of distro in 16 and 32 amp sizes are where you should start, this has already been suggested.

suggested, and was all that was originally requested. :)

Right back to the start of the thread, my only question on current was are 16a or 32a outlets more common in venues, the only question I had was based around having the most single setup with the least adapters. (it has been pointed out that 32a in in the most versative, trying to adapt a 32a outlet to a 16a cable run will require intermediate fusing for the cable run.)

My requirements: 16 amp is more than I need, 32 amp is more than twice what I need. I've not lost sight of that. 

(half the replies seemed to not read that, or ignore it and base their advice on what their FAR bigger requirements either are, or what they wished that they could be if they bought a bunch more gear.) - so i've started thinking if people aren't reading anyway...

I wanted a simple distro and a break outbox in a single unit.

I wanted either RCD + MCB or RCBO that were rated at what the equipment needs, (and rated lower than the supplying circuit.) so that if something pops it would be at my end, something that ideally I could control rather than have someone go looking for fuse boards/consumer units etc...

And as there are occasionally outdoors gigs, suggested that I wanted everything using IP rated for outdoors use. 

(Otherwise I could have easily just bought a rack mount IEC strip for plugging amps into as my breakout.) (Second hand Samson power brite includes MCB more than enough outlets and second hand is about £30, 1u rack mount with a light as well...)

Since that simple series of questions:

What are common outlets available?

What common breakouts might I forget.?

is there anything I think I need that I probably don't? (power monitoring was listed as this.)

Are there any legal part I'm forgetting?

there have been answers saying everything from:

Just buy it, buying is expensive, buying is cheap, it's not a thing that can be DIY'd. offers for other people to DIY it for me, you'll need an engineer, you don't need an engineer to build it for you. And a side story about qualifications, what about 3 phase? now something about plywood...

If i'm honest I was a little disheartened when this was dug up yesterday, I thought it had run its course.

confused.com wrote: The only 125 amp c/o

My mistake, I read the wrong specs, I meant the 4 pole 100A C/O (which would be ample for 63 Amp.) -not that larger 4 pole c/o don't exist but I don't need anything even half that big anyway.

confused.com wrote: Now if that's what you have have chosen you are heading for a universe of pain

I haven't chosen anything.

confused.com wrote: The venues that have 125 amp outlets are expecting you to turn up with over 100 kW of gear. Do you need to worry about that yet?

I will _never_ need to worry about that!

As I said, I'm just having fun playing in a band. (and trying to do it safely.) when 100kW of gear is needed, it will be someone else's problem. (not mine!) - I don't think that there is a band in the world that owns their own 100k rig?

I'm not renting out my gear, I have no plans to rent out my gear etc. So I'm never going to inherit anyone else's 100kW problems either!

MattStolton wrote: Don't do it.

If the stupidly large current rating and cost of such a thing were not a clue... To be clear.  I'm not going to build that... 

However, I do take some issue with this message that this cannot be done. or it can't be safe. 

Or worse, it s a bad idea because it isn't commercially available. or that the energy involved is somehow unmanageable. or it will take far too much thinking.

As to why I see that as an issue... (or why I think the arguments are weak.)

Commercial availability: (or)

confused.com wrote: Nobody in the touring world has a one box distro solution for the whole stage, it doesn't work that way.

A 12U box filled with 5 amps and a distro is not "commercially" available. but it is widely put together by people with no formal qualifications (there is no formal qualification in bolting stuff into a rack case.)

That doesn't make it inherently dangerous, or a bad idea. 

Sure there are dangers involved, both in terms of the amount of energy going into the box with that amount of amplifiers in it. also concerns about weight etc. fill a box with 5x 20KG amplifiers and it falling from a truck onto a foot would easily cause severe crush injuries.

a single 2u box with 1 amplifier in it is both not commercially available as a single assembled component, and is not how it is done in the touring world.

There are loads of examples like this where "thing X" isn't available off the shelf. that alone doesn't mean it can't be done, or shouldn't be done. or that there may be a single person with an esoteric need. 

Energy Involved:

The welding analogy is interesting.

A 2000w amp connected to a 2 Ohm speaker: that's ~31A/63v - that'll weld steel plates together quite easily.

In the grand scheme of things, that's not even a crazy large amplifier. certainly you could (ignoring losses) run that from a 13a household socket.

Clearly the amount of energy isn't a concern, people put amplifiers in and out of service all the time.

I won't hold my breath for some great deals for anyone clearing out these dangerous items with enough power to weld metal... It's not the energy involved, it's how you treat that energy and what protections are put into place.

Thinking involved:

The idea that this somehow involves some sort of degree in rocket science completely alludes me. That it's too complicated for mere mortals to consider. 

Following on from the complete sarcasm (borne from Efiques comment that he has one of those 3 phase to single phase leads) I've gotten nine tenths of the way to something that would work in five minutes. 

The more people say that this CANNOT be done. the more i ask why? only to be told it cannot be safe, it's just not how it is done. etc...

The more i'm inclined to think: I'm sure all it needs is a little thought.

anyway, another ten minutes in Visio. and I've corrected the remaining issue: which was.

MattStolton wrote: Fusing fail.

imageoven wrote: Top switch up, 2nd switch down = widow maker I believe?.

back of Unit, 

3phase inlet at whatever size you need --> 3phase fused breaker at whatever size you need.

1phase inlet at whatever size you need --> 1phase fused breaker at whatever size you need.

These are isolated from each other by a changeover switch.

following the changeover switch you may use whatever fused breakers or RCD devices you deem necessary.

If I were to make suggestions on fused breakers, I'd suggest using RCBOs

B or Z curve on large inlet breaker, (e.g 32A or 64A) with 100mA leakage detection.

C curve on smaller outlet breakers, and 30mA leakage detection.

as a starting place, and then for people to consider what they are running from there, (e.g lots of devices with SMPS, LED screens etc, and change those as needed.)

This may be built in either rack case or rubber box.

Any metal panel should be earthed.

the earth can be common for the whole system, this isn't generator/mains power changeover there is no need to consider earthing inside this device for that traditional transfer scenario.

A bus bar on the Single phase side of the transfer switch should be used to split the live conductor for connection to the 3 phase poles of the live switch

Neutral conductor should be sized as appropriate for current rating. 

Metering voltage/current may be added if necessary.

safety indicator (Neon) may be added to show live connection on input (Before transfer switch.) 

Internally the wiring may either be bundled with the appropriate derating applied as per IET charts. or used with loom spacers such that no derating is needed.

Crimped ferrules should be used on the end of each stranded wire. (stranded cable ends *must not* be soldered.)

Conductor diameter will depend on the inlet and outlet types chosen.

That's a schematic and a description of something you can you to draw power from EITHER single phase or three phase systems, with correct fuses, conductors, plugs, termination, wire spacing/bundling, earthing, fusing and leakage considered. 

I've not shown neutral connectors to the breakers before the outlets as you would need if these were RCD, RCBO, or 2 pole MCB. 

It CAN be done.

I'm still not going to do it, I've no use for it!

but you've already had all the advice you need

I am grateful for that advice.