Advice on Refit Infrastructure

[BenEdwards]

Hi, I help out at a voltmeter venue in Bristol (Cube Micoplex) and we are working out the Mechanical & Electrical specs for a refit. There has been a lot of resistance for punting in DMX/13a infrastructure for modern lights from a key person but we won them round. What I am trying to work out is what type of ampage should we put into a 9m bar. We have 3 bars in the sky plus 2 short bars above auditorium and are planing on putting in 2 perch bars. We also are planing on putting in 4 floor level socket sets which will have a couple of 10a circuits and DMX/13a power.

 

So what kind of wattage do good modern LED fixtures draw?

 

Are we likely to need more than 13amps for the 3 9m bars in the sky?

 

The other question is are there any other fixtures (like strobes and scrolers) that we are likely to want to connect to the 13a circuit? And what type of watts should we allow for them.

 

We are trying to design future proofed wiring and due to the nature of The Cube, and timeframe of the refit, working out exactly what fixtures to use is going to have to wait till after the refit.

[dbuckley]

The other question is are there any other fixtures (like strobes...

 

If you are contemplating sticking Atomics up they should have a dedicated 16A circuit each. You can get by with less, but you may need to reduce the output of the Atomic and/or limit what you do with them to prevent overloading.

[Guest]

Hi Ben

When you say 'what do good modern LED fixtures draw' I would say in terms of LED Pars etc a 13a supply to each bar would be ample, however if a large rig of moving fixtures was used, or indeed an Atomic strobe, power could become a limitation.

 

Edward

[BenEdwards]

I think we can rule out the strobe as it does not seem 13a domestic is sufficient and it is 13a we are looking at. What is the power consumption of moving head LEDS lively to be? Don't see us using them due to dost but just asking.

 

Maybe a 13a circuit at each end? Don't see us having more than a cope of them on each bar f we do get them. I guess I am asking how many are we likely to be able to use on a 13a circuit?

 

Ben

[OllieDuff]

You probably don't want 13A sockets in the grid, even for hard power. Avoiding having to climb a ladder to change a fuse is one of the main reasons that conventional dimmed lighting uses 15A (for the avoidance of doubt, I'm referring to the round-pin unfused BS 546 Type M) sockets. A very common way of separating hard and dimmed power is to use 16A ceeform (EN 60309) for hard power (which on the back of most decent led fixtures will be adapted to PowerCon but that's an issue to be resolved once you've specced your fixtures), protected by a suitably rated MCB on the distribution board.

To answer the original question, a single 16A socket per bar equates to around 3500W. An LED wash mover, using the Robin 600 as an example, might draw around 400-500W per fixture so you could comfortably power six of them off one socket - which should be sufficient for a layer of backlight. A static LED fixture might draw in the region of 150-200W each so you could have quite a few of them per bar! A 700W discharge mover might draw about 1kW, so you could only use a few per socket. As for a decent strobe like a Martin Atomic, you'd need a dedicated circuit per strobe.

If your venue power supply will support it, you might consider having two hard power sockets per long bar - one at each end to make cabling easier - and one on each of the short bars. That's only a rough guess on my part of course, and will depend on your actual needs.

[Jivemaster]

There is no place for 13a connectors on lighting bars. As above industry standard is 15A for dimmed power and 16a for hard power.

 

The reason for avoiding 13a fused connectors is to avoid going up to the bar to change a fuse that could be on the lighting control board.

 

DMX on the other hand, is very valuable on the bars for driving movers and LED fixtures. Try to get a proper isolated DMX splitter so that you can send each bar it's own line of dxm. this insures you against the whole system collapsing when someone gets the connector topology wrong.

[adam2]

13 amp sockets find little favour for the reasons already given.

 

IMHO this thinking is behind the times with LED and discharge lanterns. These very seldom blow a fuse therefore the objection to having to change a fuse up high is more theoretical than actual. Incandescent lanterns by contrast blow fuses fairly regularly when the lamps fail, and the fuses should therefore be readily accessible.

 

If 13 amp sockets ARE to be used then I suggest a 20 amp radial circuit per bar with a generous number of 13 amp sockets, possibly a 32 amp radial on the larger bars. This will minimise the use of multiway 13 amp leads since most fixtures will be plugged directly into a fixed outlet and not via a multiway lead.

 

A blown fuse in a plug is then of no real concern, it should only ever happen in the event of a fairly major fault in a lantern, that requires that the lantern to be removed to ground level for repair or replacement. Used thus, the only light that is extinguished by the fuse failure is the one that was defective anyway.

 

 

 

[BenEdwards]

Thanks everyone, 16amp is is.

[alistermorton]

But,as mentioned, make sure you have the requisite circuit protection in place.

[kerry davies]

I am going to do the boring bit here because I know a little bit about the venue. Get an electrician in to check out the existing supplies and advise on what you can do with what you have got. There are plenty of good theatre techs around Brizzle and several BR members are within walking distance.

 

For others, The Cube has a long and complex history and became a cinema after some guerilla projectionists set up a not-for-profit workers cooperative. A fine concept but involving a lot of DIY input. If they are doing a re-fit and upgrade to a more mixed use venue then the basics need checking out first before decisions on what can and cannot be powered from the existing supply.

 

The headroom, from memory, is extremely limited so movers might be a problem and depending on where FoH bars are located they alone might be an issue. Yes, I am a miserable old git but I would hate to hear that after lobbying for XY and Z kit it blows the ABC of the mains supply and you can't use your investment.

[BenEdwards]

I am going to do the boring bit here because I know a little bit about the venue. Get an electrician in to check out the existing supplies and advise on what you can do with what you have got. There are plenty of good theatre techs around Brizzle and several BR members are within walking distance.

 

For others, The Cube has a long and complex history and became a cinema after some guerilla projectionists set up a not-for-profit workers cooperative. A fine concept but involving a lot of DIY input. If they are doing a re-fit and upgrade to a more mixed use venue then the basics need checking out first before decisions on what can and cannot be powered from the existing supply.

 

The headroom, from memory, is extremely limited so movers might be a problem and depending on where FoH bars are located they alone might be an issue. Yes, I am a miserable old git but I would hate to hear that after lobbying for XY and Z kit it blows the ABC of the mains supply and you can't use your investment.

 

The Cube was upgraded from a cinema to a mixed use venue around 15 years ago. There are 2 rank dimmer packs which deliver 10amp per channel (12 channels). There is a PA with 32 channel soundcraft desk etc. Buy yes, we are talking to an electrocution in terms of what is possible and what we have and what we could have. The building is getting a major refurbishment (we have already had the architects do the plans and are at the stage of M&E).

 

The problem is the lighting is so limited and antiquated is is not rewarding to use and various very good lighting people have been involved over the years but the current infrastructure and kit we have, cube politics etc. means that non of them are active at the moment (although they are giving advice).

 

Currently we are only looking at infrastructure, exactly what fixtures we end up with is a another story but we would like to move from the DIY circuits made up of extension cables (around 16) with 12 dimmer channels to IWBs and 24 or 36 dimmer channels and infrastructure for non generics.

 

Ben

[alistermorton]

Buy yes, we are talking to an electrocution in terms of what is possible

 

You might get a shock.

 

http://www.blue-room.org.uk/public/style_emoticons/default/wink.gif

 

 

 

[adam2]

Thanks everyone, 16amp is is.

 

 

Sounds good to me.

13 amp is IMHO not as bad these days as some people feel, for the reasons I have already given. 16 amp is however the established convention for non dim power, and there is much to be said for following the convention especially as hired or borrowed kit intended for non dim circuits is likely to come with 16 amp plugs.

 

I presume that dimmed circuits will use 15 amp plugs, also in line with established convention.

 

 

 

[BenEdwards]

Thanks everyone, 16amp is is.

 

Sounds good to me.

13 amp is IMHO not as bad these days as some people feel, for the reasons I have already given. 16 amp is however the established convention for non dim power, and there is much to be said for following the convention especially as hired or borrowed kit intended for non dim circuits is likely to come with 16 amp plugs.

 

I presume that dimmed circuits will use 15 amp plugs, also in line with established convention.

 

 

Yes, 15amp round for dimmable circuits.

 

Interesting what you way about 13mp. We have one place where we may put a couple of lamps that is above the sound booth. These will probably be generics. A 16a seems OTT for this and there is already 13a domestic there. May not put 16a in there.

 

Ben

[paulears]

This is all round the wrong way. You will have a few people who are in control of the money, yet you are having trouble matching wants, needs and desires with what money and existing infrastructure can handle.

 

Before you do anything, you need to find out what capacity you have available for electrical services, then plan accordingly. Extra power could be sitting there, unused, or you could be up against a hard limit. Once you know there real limit, you can plan what goes where. You need to check that everyone involved is working in areas they are competent. The people who mentioned 13A are clearly not familiar with how it's done, but they may know more about some other important area. If you don't want to waste money - you all need a big table to sit around and perhaps do a star chamber style session to sort out the way to get maximum use of the money.