jstroud Posted February 22, 2008 Share Posted February 22, 2008 Hi guys, I am designing yet another production! This time it's "A midsummer Nights Dream". I am looking to hang around 25 - 30 standard lights (normal everyday bayonet cap bulbs) from the cieling of our studio, I want them to be able to drop from the ceieling and be dimmable as one unit. In my mind I see the lights hanging but not lit very brightly, just enough so that you can see the filament lit slightly but it not giving our very much light. Now I am wondering whether I need to hang 25 lights and wire them up in series plugged into a standard dimmer rack (or in groups of say 5 lights per channel) but im not sure what kind of pull this would put on the dimmers, and how safe it will be! I think some maths is in order... Would like to know others opinions of this idea... ThanksJ Stroud Link to comment Share on other sites More sharing options...
Ynot Posted February 22, 2008 Share Posted February 22, 2008 OK. First off, using a 40W BC lamp, for example, on a standard 10A dimmer channel, you can drive well over 50 lamps with ease. in fact with many dimmers the more the better as you'd not then need a dummy load. The maths:P=IV, so max power from a 10A dimmer channel at 230v (nominal) = 2300W2300 div by 40 is 57.5 lamps. However, these would NOT be wired in series, but in parallel. Question, however...How are you planning to drop them them in on cue? Or have I misread your post? I read it that you want to lower them in during the performance.. EDITCaveat attached:Reading your profile and see you're still just 17 and a student. I would heavily recommend that this amount of new wiring be at the very least checked by a competent electrician before use. Link to comment Share on other sites More sharing options...
karl Posted February 22, 2008 Share Posted February 22, 2008 If you want to see the element glow make sure you get clear bulbs not pearl (opaque) ones. The majority of normal domestic bulbs are pearl, especially 60W and 100W ones. Link to comment Share on other sites More sharing options...
Don Allen Posted February 22, 2008 Share Posted February 22, 2008 If you wire lamps in series, because they have different resistance values due to slight physical composition characteristics, one will glow brighter that the others on very dim settings. You need to have them in parallel to try and give them a chance to be roughly even intensity. Depending on your dimmer, such as bottom set or preheat etc, you may find the lamps glow faintly even with the channel fader at zero. Link to comment Share on other sites More sharing options...
woody74 Posted February 22, 2008 Share Posted February 22, 2008 ...the cieling of our studio, I want them to be able to drop from the ceieling and be dimmable as one unit. This part of it actually scares me more than the wiring bit (and not just the spelling). Flying that much glass and wire (and whatever it's all hanging off of) over the actors, even with a proper fly system, is a sketchy proposition. And if you are doing it from the ceiling of a studio, that implies to me that you'll have to get creative with wire and rigging. Be careful and smart; and get someone qualified to assist on this endeavor. -w edit: there is nothing new about this idea that makes it "fancy"; be careful not to alienate yourself. Link to comment Share on other sites More sharing options...
paulears Posted February 22, 2008 Share Posted February 22, 2008 I've been thinking about this one, and the safety and technical problems are quite minor really - what are we talking about here - a load of pendants? Well the wiring at the won't take much time for somebody to check - and after the first few are on, the wire stripping skills will be pretty good - so that's ok. The other end has the need for 20-30 cables to be connected to a dimmer. The easiest way would be to terminate every one with a 13A plug with a low rated fuse, and then 4 way them up - the load is pretty low. The final one can have a 15A plug. Pretty good way to get experience of putting on plugs too! When I was teaching, we did something similar, and used it as an assessment - gave everyone the bits and then they all were making up cables! The bit with pulleys and string will be interesting - but quite do-able. Sounds a nice project to me. As for the safety aspects, well as long as they are tested before use - all is well. Link to comment Share on other sites More sharing options...
steve h Posted February 22, 2008 Share Posted February 22, 2008 Pretty good way to get experience of putting on plugs too! I always had trouble with the school where I was in stoke with putting plugs on equipment...basically as a student they weren't too happy about this and the HSO put up a fuss and made the sparky in the DT department do them all (well...saved me a job!) I know different county authorities have different H&S regulations so it may be worth checking before you do this. Sounds like a nice idea though with all the lights though Steve Link to comment Share on other sites More sharing options...
paulears Posted February 22, 2008 Share Posted February 22, 2008 schools have different rules - dreamed up because they have mostly children, with young adults in the 6th form. Colleges are usually different. Their courses are also run in a more professional context - so they see their role as preparing people for work or more study. Many grades are given for actually doing practical things. So their students use ladders, electricity, soldering irons etc etc - that would be considered dangerous in a school. As often seen on here, schools frequently don't have any staff with professional experience, and their technicians rarely know much about what is being taught. The few exceptions on here know who they are. The more industry minded colleges do it very well, and understand how the business works, and make sure they can deliver the goods with safety. Quite frankly, the schools and colleges who insist that focusing is done at ground level, power is only handled by 'qualified electricians' and have other daft rules shouldn't be running the course at all! It's plain silly to have a ban on fitting plugs, when this is one cause of common injury in the home, let alone the workplace, and learning how to fit one safely is a damn good skill to have. The simple thing nowadays is to automatically ban things just because the powers that be don't have the correct staff, or don't trust the ones they have! Turned into a bit of a rant - sorry! Link to comment Share on other sites More sharing options...
steve h Posted February 22, 2008 Share Posted February 22, 2008 Dont worry, I know where you're coming from...when I say school it was a combination of school and college, and I do understand that the practicals can be useful. As I was leaving a health and safety officer came onto the board of governors and caused mayhem. He came up with the face we would have to switch from using an A frame ladder, to scaff tower - with airbags around the outside! Also we had to have the thing PE mats along the front of the stage incase a performer fell off - I think I got out at the right time. I didnt mean to lay down the law in my previous post, I just wanted to point out it may be worth checking these things Link to comment Share on other sites More sharing options...
jstroud Posted February 23, 2008 Author Share Posted February 23, 2008 Hi guys and thanks for your response. Yet again the whole "age" thing crops up, however I am past caring, although I may be 17 I have got the common sense to get my work checked, although I've never had a problem before with a good 4 years of experience in the boring old wiring plugs down at my local amateur theatre! (working up from the bottom!). As for the spelling "ceiling" I'm very sorry, it was a rushed post written in college! I think you have all gathered my general aim, and so I will expand: We have a basic lighting structure rigged in our "Studio" comprising of 4 main lighting bars containing 48 built in sockets on the trusses. (we also have various bits of scaffolding bar available to rig for special in between these bars. My idea would be to use "pendant" style lamps, and some white 5amp flex so that they look neat, I would hang maybe 20 (rather over ambitious with 30!) lights from the lighting bars using their flex against the round lighting bars as their "pulley" as they would only need to drop around 1 meter from the bars. Then comes the real question. How to actually wire up the cabling from here. I think I have got the general gist of the fact I would wire them in parallel. However do I need to go to the expense of buying 20 plugs etc., or is their another way? (e.g - using chocolate blocks (obviously rated highly in terms of amplitude) or some other form of "terminal" style connection. Again this may kick up the fuss of why is a 17 year old doing all of this electrical stuff but A) I have the skill to do it, my granddad first introduced me to the world of wiring up batteries and fairy lights when I was around 6 or 7 (a good 10 years ago, and I have progressed through my own inane need to take things to bits, and my work at my local theatre into lighting.) so no worried posters need be necessary, and all of my work will be checked by a qualified member of technical staff at college) P.S: This is a college production and is a part of the coursework counting towards my final A-Level... I have rather a lot of free reign, and am allowed to wire plugs! Thanks AgainJ schools have different rules - dreamed up because they have mostly children, with young adults in the 6th form. Colleges are usually different. Their courses are also run in a more professional context - so they see their role as preparing people for work or more study. Many grades are given for actually doing practical things. So their students use ladders, electricity, soldering irons etc etc - that would be considered dangerous in a school. As often seen on here, schools frequently don't have any staff with professional experience, and their technicians rarely know much about what is being taught. The few exceptions on here know who they are. The more industry minded colleges do it very well, and understand how the business works, and make sure they can deliver the goods with safety. Quite frankly, the schools and colleges who insist that focusing is done at ground level, power is only handled by 'qualified electricians' and have other daft rules shouldn't be running the course at all! It's plain silly to have a ban on fitting plugs, when this is one cause of common injury in the home, let alone the workplace, and learning how to fit one safely is a damn good skill to have. The simple thing nowadays is to automatically ban things just because the powers that be don't have the correct staff, or don't trust the ones they have! Turned into a bit of a rant - sorry! That's no problem, it is the same rant that I have! however my college is rather lenient on such matters, (the HSO is kept far, far away!) Link to comment Share on other sites More sharing options...
GridGirl Posted February 23, 2008 Share Posted February 23, 2008 Then comes the real question. How to actually wire up the cabling from here. I think I have got the general gist of the fact I would wire them in parallel. However do I need to go to the expense of buying 20 plugs etc., or is their another way? (e.g - using chocolate blocks (obviously rated highly in terms of amplitude) or some other form of "terminal" style connection. You could use festoon fittings; they're easy to wire up (although much easier with new fittings than re-using old ones!) and pretty quick to do; the only problem I could see is that each fitting will have two wires - into and out of the fitting - and they come in from the sides rather than the top. However, cable ties could probably solve this pretty neatly for you. We've just finished a show where we had about 300 light fittings as part of the set and the festoons worked very well for us. Link to comment Share on other sites More sharing options...
diarmaidol Posted February 23, 2008 Share Posted February 23, 2008 Just a quick note ,(I'm not an electrician) I think it always best if making a unique installation to make the wattage of the bulb match the need , I think a 15W Pygmy bulb might be exactly what you need , so if you use say 20 of them per circuit you are only pulling 150 W. As for the wiring , using a 15W bulb you would run 5 bulbs in a Christmas tree light style chain. Wire into your pendant lighting fitting then take your live/neutral/gnd for the next bulb from the previous one to create a parallel circuit. if you only use 5 bulbs then you are not going to pull any serious load that could get you into trouble. All that said , if you know an electrician have a quick chat with them. If you want to get on in lighting at all , it pays to know a friendly sparky who will always give you advice about some of these more interesting temporary installations. Link to comment Share on other sites More sharing options...
themadhippy Posted February 23, 2008 Share Posted February 23, 2008 However do I need to go to the expense of buying 20 plugs etc., or is their another way? (e.g - using chocolate blocks (obviously rated highly in terms of amplitude) or some other form of "terminal" style connection.Hows about celling roses,hole and strain relief lugs built in for the pendant drop,2 x 3 way, 1 x 2 way terminal block and an earth terminal all in a nice circler enclosure Link to comment Share on other sites More sharing options...
Jivemaster Posted February 23, 2008 Share Posted February 23, 2008 I like the idea of lots of lights. My B&Q has lots of decorative fillament lamps with clear enclosures and glow fillaments. For twinkly starry effects look also at things like this; http://www.terralec.co.uk/display_and_deco...in/17540_p.htmlOne commercial unit complete for a lot less than your project will cost in wire! Can you make anything from it? Remember that if you use white wire these will be very brightly lit by adjacent luminaires, and they may well cast shadows. Link to comment Share on other sites More sharing options...
steve h Posted February 23, 2008 Share Posted February 23, 2008 Yet again the whole "age" thing crops up, however I am past caring, although I may be 17 I have got the common sense to get my work checked, although I've never had a problem before with a good 4 years of experience in the boring old wiring plugs down at my local amateur theatre! (working up from the bottom!). Im sorry if I have offended...my comments where no in no means meant to be a criticism of your skills. Im 19 and I work in a school yet I still face problems with people having problems with my age. (kept getting called "boy" by the school shows producer) but anyways...unfortunatly many students do not have the same skills as you so these regs have to be in place, as im sure you understand. Back to your idea. Using the bars as the pulley may be fine for one light...but for 20 lights you may wish to put something in place But nice idea, please post some pics of the finished thing! Steve Link to comment Share on other sites More sharing options...
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