RoyS Posted February 14, 2009 Posted February 14, 2009 Hi All, I will be purchasing some (20) LED PAR56’s for schools LX rig the wattage rating for these fixtures is 15W at 230V each. I will mostly running them as short throw cyc type luminares from two LX bar above a school stage. Currently the bars have 8x 15A circuits each. Therefore need to add hard power & DMX for the LED’s. So my questions are: 1. What would be the best way to run power into the bars and how to terminate (13, 15 or 16A ?(I feel like 13A would be the cheapest and possible the easiest to implement and want to avoid X-Y jumpers where possible)2. Bearing in mind that the bars will never run moving heads and therefore the hard power does not need to be over the top. Will 1mm or 1.5mm be OK?3. How to run DMX to the bars and again how to terminate e.g. a mounted box(s) and plates with a male and female XLR and a loop through when not used…. I know how this would be done in a touring rock situation, but am unsure in this context... Many thanks for all suggestions on this. Cheers. Roy
sirrus Posted February 14, 2009 Posted February 14, 2009 Hey there RoyS, Why waste sockets? - As LED cans are relatively light weight, why not just add a second scaff pole to the current grid and run the pars off that? Assuming it’s for an installation, Stage Electrics have some good solutions (sit on the bar Distro panels e.t.c), and if it’s not for installation or if money is tight then you could just run cable up there... to a distro box on the bar (Again Stage Electrics for that one) and maybe cat5 for the long DMX run. Credit crunch and all that :( Personally, I would run 16a ceeforms on the basis that it’s more practical and you can get them all in one run (using splitters). And yes, 1mm or 1.5mm should be fine, due to the parcans being low wattage. But why not just daisy chain the pars as opposed to having each one with its own socket on the bar?
RoyS Posted February 14, 2009 Author Posted February 14, 2009 Hi Sirrius & thanks for the quick reply. I must admit, because money is tight & the bars will be out of sight, I fancy daisy chaining 4x way 13A sockets for power and daisy chaining DMX as you suggest. I await the wrath of the BR community!!...... Cheers. Roy
sirrus Posted February 14, 2009 Posted February 14, 2009 Not a problem my friend :P Yes, at the end of the day if its not seen ... it doesnt exist :( (so long as its safe ** laughs out loud **) ... and Yes, remember cat5 is very cheap and effective for a perminant run! :) sirrus
Davethsparky Posted February 14, 2009 Posted February 14, 2009 If you are after a very low cost soloution you could probably convert one of the eight existing sockets on the bar froma dimmer outlet into a hard power outlet. The size of the cable used if you wire a new outlet in will be governed by the rating of the overload protective device, grouping factor, ambient temperature, thermal insulation, voltage drop, conductor operating temperature/type of cable, rating of the outlet. As a rule of thumb without knowing the details of the installation I would suggest that 2.5mm (1.5mm for MI) may be appropriate, but you must get this checked by someone who has made a proper assessment of the situation. If you install socket outlets the supply and cable size should be sized according to the outlet not to the load you intend to connect to it.
Barney Posted February 14, 2009 Posted February 14, 2009 2. Bearing in mind that the bars will never run moving heads and therefore the hard power does not need to be over the top. Will 1mm or 1.5mm be OK? Bear in mind that someone will one day plug something in to your hard power sockets that will be over the top. This may be others after you who haven't realised what you've done, or even a student when you're just not around to ask. Any hard power outlet that you decide to run in 1mm or 1.5mm (or any other mm) should be protected by a suitable fuse/breaker that will blow/trip well below the maximum rating of the cable. HTHBarney
niclights Posted February 15, 2009 Posted February 15, 2009 It might not be pretty, but I see nothing wrong with using 13A 4-ways plugged into the 15A outlets and route the other end back to 13A hard power. Certainly the cheapest and easiest - just rewire some basic 4-ways with 15A plugs.
dosxuk Posted February 15, 2009 Posted February 15, 2009 It might not be pretty, but I see nothing wrong with using 13A 4-ways plugged into the 15A outlets and route the other end back to 13A hard power. Certainly the cheapest and easiest - just rewire some basic 4-ways with 15A plugs. I wouldn't do this in a school, some bright spark of a kid will end up using them inappropriately (probably trying to dim the LED cans) - there's been enough threads with school kids asking if they can do this recently. IMHO, the other suggestion of changing one of the sockets to 13A (and the supply end) would be safer, however... @OP - how are the 15A sockets powered? Do they go through a patch panel, or are they hardwired to dimmers?
RoyS Posted February 15, 2009 Author Posted February 15, 2009 Utalising one of the 15A circuits on each bar with 13A plugs at tails end 13A sockets on the LX bars has gone through my mind. Although 8x 15A on each bar, the sockets at each end are rarely/never used. The bars are wired with 1.5mm. Rewireing the current plug/sockets will avoid using jumpers at both ends. Then using trailing 13A four ways to distribute power to the LED's. The hard wire supply will obviously have to be proteced and accessable in case of having to reset the fixtures. This still leaves the DMX chain. The distance from the patch area to the bars is less than 3M at most. So I don't think I'll bother to hack into the LX bars and bother putting DMX sockets on the pipes. If this was a new build the situation would be different.. Thanks for all comments thus far..
sirrus Posted February 18, 2009 Posted February 18, 2009 Just a quickie, since this is in a school enviroment... Perhaps the equipment might not always want to be on that LX bar? e.g. they might want to use the LED cans somewhere else for something else, if RoyS only cable ties a couple of 4 ways and runs a long cheap (cat5 time!) run of DMX up to the bar then it can be easily moved around the venue and therefore simpler for the kids, and cheaper! And then if the money appears in the future, it can be done properly? sirrus
RoyS Posted February 19, 2009 Author Posted February 19, 2009 Cat 5 is not screened, so how could you use if for DMX?
david.elsbury Posted February 19, 2009 Posted February 19, 2009 Who said DMX needed to be screened?Roy, search the BR for CAT5 DMX... we've been here before. (oh, and you can get screened CAT5. It's called STP [sheilded Twisted Pair], amongst other things)
RoyS Posted February 19, 2009 Author Posted February 19, 2009 David - Thats a revelation to me!! For install work that must be great. In my application, where fixtures will be moving, it's not the right choice. Cheers. Roy
Ian H Posted February 19, 2009 Posted February 19, 2009 Who said DMX needed to be screened?Roy, search the BR for CAT5 DMX... we've been here before. (oh, and you can get screened CAT5. It's called STP [sheilded Twisted Pair], amongst other things) http://www.cpoint-lighting.com/pro_products/index.htm Currently using Cpoint DMX Cat5 cable adapters here --- nice and easy Ian
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