Building our own lighting setup

[szymon]

Hi there folks,

 

I've just taken on the lighting for our local parish panto group. We put on a pantomime once per year in our parish centre hall. Until now have hired lighting, but we'd like to buy our own, both so that we don't keep hiring each year, and also so that it can be used on the stage at other times when needed. It's been a long time since I've done anything with lighting; my first degree was in Drama and Theatre Studies, but that was in the early 90's. I work in computing, hold an MSc and Chartered Engineer status, worked as an electrician's boy for a while, and am a fully licensed radio amateur, so I'm not afraid of electrics or electronics, but this is an area where I really don't want to get anything wrong so I'm reaching out for advice.

 

Our requirements are quite simple; we want the actors to be visible! We'll have a couple of scene changes, some where the lights should be darker (in a cave), some representing indoor light, and some representing the outdoors on a sunny day. The parish centre has a stage with a traditional proscenium arch and curtains. There is a lighting bar to the front (well, a scaffold pole attached to the ceiling) and mount points behind the curtain, to the sides, and to the rear. There is a dedicated 63A supply (they claim three-phase but it's a blue three pin socket on the wall, as pointed out below that means it's probably just a single phase but it's a dedicated 63A supply just for the lighting). We have a box of various cables, mostly DMX and 15A BS546 extensions. Last year we rented the following equipment (taken from the rental invoice):

 

2 Way Splitter 63API-63ASkt

Strand Act 6 + 6 Channel Rack

25 Metre Socapex 6 Way Multicore Cable (2)

Socapex 6 x 15 Amp Plug Spider (2)

Socapex 6 x 15 Amp Socket Spider (2)

15 Amp 15 Metre Ext Cable (4)

Par 64 Wide Angle 1000 Watt (6)

Cantata Fresnel 1200 Watt (4)

Barndoors for 2k Fresnels (4)

15 Amp 2 Way Mains Splitter

DMX 512 Cable 25 Metre (4)

Cantata 1200 Watt F/Spot Kit

Colour Magazine for the above

 

I've been out hunting for equipment on the second hand market (before I found this site), and have so far purchased:

 

6 x Par64 (I believe wide flood, although I've not looked at all the lamps yet) - £50

6 x Fresnels (various brands, three Starlette 1K, two other 1k, one I think 500w) - £172

 

All of the lamps have 15A BS546 connections.

 

I'm now looking at dimmers. The original idea was to buy some cheap dimmers, however it seems that no cheaper dimmers have 15A sockets; to get modern DMX controlled dimmers with 15A sockets I'd need to pay hundreds of pounds, which is beyond our budget (ideally around £100 for the dimmers). So the way I see it, I have four options:

 

1. Buy a dimmer with hardwired connections. I would then cut the ends off our extension cables and wire them straight to the dimmer. Something like this is a good example, although overbudget: http://www.ebay.co.u...d-/221617038162 This has six 10A channels; I would wire two lights to each channel (2000w / 240v = ~8.3A).

 

2. Buy some inexpensive 4 channel dimmers. Two problems: the ones I've seen (e.g. those for £60-odd from CPC) state a maximum overall load of 10 amps (even though each channel can be up to 10 amps?), and they have IEC power outputs so I would either have to use some form of converter or remove the 15A plugs and fit IEC connectors. (How do people usually do this -- is there a commercial source for converters?).

 

3. Buy an old analogue dimmer, for example this: http://www.ebay.co.u...r-/321581926200 and then build some control circuitry (e.g. GPIO from a Raspberry PI) or get a DMX Demux unit as mentioned in the ad (which I know very little about)

 

4. Hire the dimmers for this year, save the money and buy a rack with 15A sockets in future.

 

In terms of control, I'd either buy a very simple inexpensive DMX lighting desk, or for £10 I've seen this https://secure.chamsys.co.uk/magicdmx USB->DMX cable which with a laptop looks like it could be quite good.

 

Any and all suggestions or comments appreciated (even if they're along the lines of "what the hell are you doing, don't do XXX!").

 

Many thanks,

 

-simon

[Shez]

There is a dedicated three-phase 63A supply (blue three pin socket on the wall).

You might want to double check that one ;)

[GR1]

You beat me to it Shez !

[szymon]

There is a dedicated three-phase 63A supply (blue three pin socket on the wall).

You might want to double check that one ;)

 

Well, I'm going based on what I've been told (I've not actually looked at it yet). It's a big old socket and at a quick glance had three pins (but yes, would be odd -- three lives, where's the neutral?). I shall double check.

 

Any thoughts on the rest of it? :-)

[niclights]

Blue = 240v = single phase. Three pins = live/neutral/earth.

[szymon]

Blue = 240v = single phase. Three pins = live/neutral/earth.

 

Indeed, I've updated the original post. I simply didn't think. Either way, it's a dedicated power supply just for the lighting, so I'm not having to plug into the mains (there's a separate MK consumer unit with 32A fuses for each ring).

[timsabre]

It would be coloured red if it was 3 phase.

 

Anyway.. IEC sockets are probably the most popular type of output on DMX dimmers, make some short IEC plug - 15A socket adaptors.

A few of this type of thing would work for you

http://www.ebay.co.uk/itm/400809431129

 

The ones of these I've seen have 2xIEC inputs 10A each, so each pair of channels can be up to 10A. You'd need some sort of distribution to get from your 63A socket down to a number of IEC's.

 

I wouldn't hardwire your extensions into a dimmer. If you're going to hardwire it then you should go all the way and install fixed sockets as well.

[c0astman]

The blue socket on the wall is (most likely) at best a single phase 32A socket and at worst a single phase 16A socket, but best get it checked.

 

Some helpful information would be about the size of the stage and how far away the lighting bars are that you use.

 

Working blind I would suggest that the 2k fresnels will be overpowered for your requirements. Most of the work I do uses 500w Fresnels that are about 7m (from the bar to the front of the stage) away from the talent. They are more than adequate. And you could have 4 of those for every 2k unit, power wise.

 

The dimmers need to be matched to the desk that will be available to all groups that can use the hall. Not everyone will/might have access to MagicQ or be able to use it.

 

A Demux converts DMX signal into an analogue signal for use with analogue dimmers, but they too need to match. Some dimmers work off 0 to-10v and others 0 to +10v. Not all demux's will do both and you can't easily mix dimmers of both sorts.

[szymon]

It would be coloured red if it was 3 phase.

 

Anyway.. IEC sockets are probably the most popular type of output on DMX dimmers, make some short IEC plug - 15A socket adaptors.

A few of this type of thing would work for you

http://www.ebay.co.uk/itm/400809431129

 

I wouldn't hardwire your extensions into a dimmer. If you're going to hardwire it then you should go all the way and install fixed sockets as well.

 

That's exactly the same unit as I saw on CPC. My worry with the linked item is that the instruction manual for it (from https://www.esr.co.uk/manuals/442-110.pdf ) says: "The Pack can carry maximum overall load of 10 amps." I think I need something like that, but where each of those channels can handle 8.3A (two 1kw lights), all up at the same time. Or am I missing something obvious?

 

The blue socket on the wall is (most likely) at best a single phase 32A socket and at worst a single phase 16A socket, but best get it checked.

Yes, definitely single phase (I only left the mention in the main post so that people wouldn't later accuse me of editing out my idiocy!). It's *much* bigger than the 16A sockets I've seen, and it has '63A' on a sticky label on the side.

 

Some helpful information would be about the size of the stage and how far away the lighting bars are that you use.

 

Working blind I would suggest that the 2k fresnels will be overpowered for your requirements. Most of the work I do uses 500w Fresnels that are about 7m (from the bar to the front of the stage) away from the talent. They are more than adequate. And you could have 4 of those for every 2k unit, power wise.

I'll measure up when I get a chance on Thursday (next rehearsal), but the stage is perhaps seven metres wide, and the light bar is perhaps three metres in front of the stage. The Fresnels I've bought are 1k (my 2k maths were from two of them on one channel).

 

The dimmers need to be matched to the desk that will be available to all groups that can use the hall. Not everyone will/might have access to MagicQ or be able to use it.

There's actually a laptop that 'belongs' to the parish centre, it's used for displaying presentations on the projector, so I was planning to install MagicQ on that. But you're right, a 'real' desk will probably be a better way to go. When you say 'matched', isn't it the case that any DMX512 compatible desk should be able to drive DMX512 compatible dimmers?

 

A Demux converts DMX signal into an analogue signal for use with analogue dimmers, but they too need to match. Some dimmers work off 0 to-10v and others 0 to +10v. Not all demux's will do both and you can't easily mix dimmers of both sorts.

Yes I don't think I'll go down this route. Simple and reliable is the order of the day.

[timsabre]

They are so cheap I would have one lamp per channel. There way be different versions which only have a single IEC in.

 

The alternative is to wait for a proper professional 6 way pack with 15A sockets or IECs to come up 2nd hand. These would take your full 63A single phase in and give you 10A out per channel.

Most of the ones I see on ebay etc don't have DMX so you'd almost certainly have to buy a demux as well. like this http://www.ebay.co.uk/itm/251703317167

 

A demux is very simple and is probably the cheapest way to get a decent setup.

[erik10_4]

The alternative is to wait for a proper professional 6 way pack with 15A sockets or IECs to come up 2nd hand. These would take your full 63A single phase in and give you 10A out per channel.

Most of the ones I see on ebay etc don't have DMX so you'd almost certainly have to buy a demux as well. like this http://www.ebay.co.uk/itm/251703317167

A demux is very simple and is probably the cheapest way to get a decent setup.

 

I'd second this suggestion. Amongst other dimmers I have the a Betapack (like the eBay one mentioned in the OP) and exactly the same model demux in timsabre's link above. It really is a very versatile and reliable setup. You would have to make up a 24 pin to 8 pin Din breakout from the demux to dimmer but I found that a doddle (there are pinouts on this forum somewhere). This gives you scope to add dimmers/fixtures to your rig at a later date. You can then use virtually any DMX control desk you fancy (or can afford).

[kgallen]

3. Buy an old analogue dimmer, for example this: http://www.ebay.co.u...r-/321581926200 and then build some control circuitry (e.g. GPIO from a Raspberry PI) or get a DMX Demux unit as mentioned in the ad (which I know very little about)

 

For "old analogue dimmer" read "the dimmer (Betapack1) that suppliers 'hate' because they last forever, rarely go wrong and if they do are easy to fix, so a new replacement can't be sold" (nod to IK B-) )

 

For me it's a no-contest if I were setting up my village hall from scratch [again] - I'd be snapping up that pair of 2nd-hand Betapack 1's [give 'em a clean and check over, maybe replace the 100K sync resistors, good as new] and a demux as posted earlier. I wouldn't be bothering with those IEC 4-way packs for my main install (sub-dimmer for some out-of-the-way location, sure) - 10A or 16A total supply limitation for 4 channels? Spend another £50 to do IEC to 15A jumpers? Pah, don't bother for the main rig, get some Betapacks up and running!

 

There's a feeling of deja-vu here from the posts this last week - no I'm not the one selling those Betapacks!!! OP might like to take a look through the posts started by funkytwig this last week or so!

[alistermorton]

I might be watching this item, too, were I in that position.

[kgallen]

I might be watching this item, too, were I in that position.

 

Darn right! Good spot, Alister.

 

Lack of a single-phase L buss bar is no issue - a very short length of 10mm2 cable serves just as well - like a bit of the H07 flex you'll be using to connect it to the 63A Ceeform!

 

 

Depending on OP location might be a long drive to Perth though...:unsure:

[szymon]

I did see that, I actually have a call out to friends on social media to see if anyone might be able to pick it up from Perth for us :-)