stephen164 Posted February 25, 2015 Share Posted February 25, 2015 Not sure if this is a power question or a lighting question... I'm about to do a show in a venue with a slightly weird lighting power setup. The main lighting power distribution board has a 63A3 upstream breaker. Dimming is four Strand 6-pack dimmers (pretty new, ~2011 vintage), hardwired on separate 32A3 supplies back to that distribution board; so you can't draw more than half power overall, not a big problem. Problem arises from the hard power, which is four 15A sockets also wired back to the same 63A3 supply (in two pairs with 20A1 breakers each), all on the same phase. I need to pretty much max out that hard power supply, meaning that on one of the phases I only have 23A left to throw at the dimmers, or I'll trip the 63A3 upstream MCB which I don't have quick access to to reset. Question is: which channels does that translate to? From the way you can convert most 6-channel dimmers between 3-phase and single-phase operation with a metal bar across the live contacts, I assume that the phases are divided inside the pack two to each channel. Does anyone know whether they're distributed 1/2/3/1/2/3, 1/1/2/2/3/3, or some other permutation? Link to comment Share on other sites More sharing options...
Brian Posted February 25, 2015 Share Posted February 25, 2015 There is no way to know how they've been wired without either a) inspection of the feeds or b) measurement. And you should check ALL the packs to make sure they are all wired the same.. Link to comment Share on other sites More sharing options...
stephen164 Posted February 25, 2015 Author Share Posted February 25, 2015 An RTFM moment: it's buried on page 10, I missed it the first time around. For future googlers: it's 1/1/2/2/3/3. Link to comment Share on other sites More sharing options...
MarkPAman Posted February 25, 2015 Share Posted February 25, 2015 1/1/2/2/3/3 is logical, but unless you check, is there any way of knowing it's not 2/2/3/3/1/1, 3/3/1/1/2/2 or even 1/1/3/3/2/2, 3/3/2/2/1/1, or 2/2/1/1/3/3 ? Link to comment Share on other sites More sharing options...
itiba Posted February 25, 2015 Share Posted February 25, 2015 I assume you know that if you meter between phases you get 400v ish and between sockets on the same phase you get 0v ish so I'd recommend (with a decent volt meter - not a maplins £5 one) spending a few minutes metering each socket to a 'known' socket as there's no guarantee phase rotation will be correct let alone wired as per the manual. Slightly O/T but I've had a 12 channel pack before which had 2 socca outputs. The first soca being 111122 and the other soca was 223333. Link to comment Share on other sites More sharing options...
dbuckley Posted February 25, 2015 Share Posted February 25, 2015 The bigger problem is that the dimmers may well be wired 1,1,2,2,3,3 internally, which makes sense, but to which supply phase does 1, 2 and 3 correspond to, and are all dimmers wired to the supply the same way? There is no reasonable alternative to checking, I'm afraid. (Yes, this is a "hard way" lesson) As Itiba points out, ff you are electrically competent and have access to a voltmeter rated at Cat3 or 4 at 600V, then that is the easiest way to figure it out. This doesn't even need the dimmer channels raised, the triac leakage will be enough to make the necessary measurements. Your reference is the hard power sockets. Link to comment Share on other sites More sharing options...
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