mrcog Posted June 17, 2007 Share Posted June 17, 2007 I was working on site at Cambridge Uni fashion show during my work experience a couple of work weeks ago and they were useinging two Dig18 dimmer racks from stage electrics and I was told to run soca from the back of the dimmers to the areas and to plug a spider onot the end. Now I understand that you plug the lights into the sockets which go into the soca and I understand that soca is a multicore but then when I plugged them into the back of the dimmers I wondered what the 15 Amp sockets were for on the front. I didn't ask at the time because the front bit of the flight case was on but I went back the next day and didn't get time to ask. Also I guess that the cable going to the desk is 5 pin DMX but each set of dimmers had it's own and I assumed that the desk would only have one, maybe two inputs (fat frog). I also didn't see that. So, my questions are, What do the 15 Amp plugs on the do?And how to you get a signal to the desk?What do the 32 Amp and 16 Amp sockets do at the back as well?And I also saw that the guy patching it was running cable from small sockets on the back to another small socket on the back (I think it was patching it anyway), so was he patching it and why do you plug a piece of cable from one socket to another of the same kind. Front:http://beeldbank.prepublisher.com/pictures/PP/STA/9/STAZ0129.jpgBack:http://beeldbank.prepublisher.com/pictures/PP/STA/3/STAZ0083.jpg Ohh and by the way, I'm asking this because I am only 14 and want to get into the industry so am asking questions so I can hopefully get a job next summer (when I'm 16) :huh: Link to comment Share on other sites More sharing options...
cedd Posted June 17, 2007 Share Posted June 17, 2007 OK, here we go Firstly DMX, there will only be one cable front to back as DMX carries the control signals for multiple dimmers, fixtures, etc on the same cable. This is arranged in a "daisy chain" fashion around all the equipment strapped to it. On larger shows you may well use more then one DMX source which is why the dimmers aren't internally daisy chained (you might want to use one dimmer on one desk, the other on another, hence a manual patch. The soca's will probably just be a paralleled up version of the 15A sockets. Imagine running 6 or so 15A cables when one soca will do. Of course you can get tail in leads but why bother with the extra bit when the dimmer can just have the extra provision? As for the 16 and 32A sockets, I see they are labelled red yellow and blue, which are the old colours for 3 ohase supply. More likely than not this rack is also a mains distro running off of a 3 phase supply. The single phase outlets are provided for maybe other dimmers that are single phase, moving heads, etc. More than likely they'll be permenantly fed. As for the Link to comment Share on other sites More sharing options...
mrcog Posted June 17, 2007 Author Share Posted June 17, 2007 Ohh ok, so the 15 amp sockets could be used or the soca's could be used. Link to comment Share on other sites More sharing options...
TomLyall Posted June 17, 2007 Share Posted June 17, 2007 Ohh ok, so the 15 amp sockets could be used or the soca's could be used.You'll be able to use both at the same time, providing you stay within the load rating of the dimmer. You'll need to do some patching on the back to make the socapex work though. It has what's called a "Wieland Patch" - named after the brand of conector used. Link to comment Share on other sites More sharing options...
benweblight Posted June 17, 2007 Share Posted June 17, 2007 Ohh ok, so the 15 amp sockets could be used or the soca's could be used. Or both at the same time, as long as your are not exceeding the dimmers safe load. The point of the patching is:There is socket for every 15amp coming off the soca's (the sets of 12 on the left), then there are four sockets for each dimmer channel (the sets of 32 on the right), so you can change what is 'patched' in where. Link to comment Share on other sites More sharing options...
mrcog Posted June 17, 2007 Author Share Posted June 17, 2007 Ahh ok, I gotcha, thanks Link to comment Share on other sites More sharing options...
tokm Posted June 18, 2007 Share Posted June 18, 2007 Just thought I'd mention this as I can't seen it covered here. Mains input to these racks is via the Multi pin connector.. Now before everyone wonders why use such an odd connector, it's to allow the rack to use a variety of different input connectors. SLX have a load of tail-in cables of both single & 3 phase variety. From 13a/16a (!!!) to 125 in both varieties IIRC. Their website doesn't list up to that, but I know they have them in stock.. cus well.. I've hired them with that tail in cable. Basically, the rack always thinks its getting 3 phase (in the sense that there's 3 lives a common neutral & earth) So when you want to use a single phase input supply, the single live core in the tail-in cable is wired to all 3 of the lives in the multi-pin plug. Then when you say ask for 3phase tail-in, the 3 live's/phase cores coming from the supply are just wired to their 3 individual live pins on the multi-pin plug. Pretty nifty system, eliminates having to have 3 single phase tails coming out the back of the rack and then having to use another bit of kit (distro) to run the things off a 3phase supply. HTH Tom Link to comment Share on other sites More sharing options...
mrcog Posted June 18, 2007 Author Share Posted June 18, 2007 Ahh ok, I uderstand why they do that as well now. Thanks Link to comment Share on other sites More sharing options...
johnhuson Posted June 18, 2007 Share Posted June 18, 2007 Just to add that not all dimmer racks have sockets on the front as well as Socapex on the back, certainly the larger racks have Socapex only. Here's an example of a fairly common rack. http://www.avolites.org.uk/products/images/art2k01a.jpg http://www.avolites.org.uk/products/images/art2k01c.jpg In this case the patch is on the top. Link to comment Share on other sites More sharing options...
Tomo Posted June 18, 2007 Share Posted June 18, 2007 And the Green, Black, Red, Yellow, Blue large connectors at the bottom are PowerLock three-phase, neutral and earth connectors of the power supply.One big wire for each of them, with the upper set being 'out' tie connectors so you can daisy-chain the power between a few racks. Obviously it matters a LOT which connector goes where, so they are keyed to make it difficult to connect wrongly! These connectors are rated at rather large currents (400A or 660A), and used for large portable systems.Newer racks would use the new colour code of Green, Blue, Brown, Black, Grey, which can lead to confusion in situations where both sets of colours are in use. Installed systems would have the wires permanently connected, via a large crimp or screw terminal, depending on the cable and rack involved. Link to comment Share on other sites More sharing options...
mrcog Posted June 18, 2007 Author Share Posted June 18, 2007 So power lock three phase is a seperate wire for each phase and earth and neutral. At what size do you turn from normal 3 phase to powerlock, 125 Amp, 250 Amp, but I understand how this might be an advantage. ANd are the outputs from the rack the 5 pin XLR's in the top right hand corner of the avolights rack? Link to comment Share on other sites More sharing options...
johnhuson Posted June 18, 2007 Share Posted June 18, 2007 Above 125amp 3-phase (largest CEE form connector available) then generally people use Powerlocks but there are still a few people still using Camlok which is a similar type of connector. The XLR's at the top right corner are two seperate DMX In's with link through Output connectors. There are two lines so that you can merge the DMX from two different desks, or you can soft patch the DMX as well. Link to comment Share on other sites More sharing options...
mrcog Posted June 18, 2007 Author Share Posted June 18, 2007 Ahh ok, I think I understand all of this now. thanks everyone for all the help Link to comment Share on other sites More sharing options...
Ben Langfeld Posted June 19, 2007 Share Posted June 19, 2007 One thing, mrcog, that I've noticed is that you seem to be referring to the DMX inputs as outputs. The dimmers do not output anything to the desk. The desk outputs DMX which is received by the dimmers. Link to comment Share on other sites More sharing options...
mrcog Posted June 19, 2007 Author Share Posted June 19, 2007 yep, that would make sense. cheers Link to comment Share on other sites More sharing options...
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