Johnno Posted January 1, 2009 Share Posted January 1, 2009 Our Zero 88 Chilli 24-channel dimmer has taken to blowing its distribution board trip (3 phase). I'll be getting engineers in to look at it but wondered whether anyone has come across the symptom before. The trip has blown about four times in the past six months always when the unit was not actually in use - most damagingly during the interval in a production in which it had worked perfectly during the first half. After the break the house lights went down, the curtain went up and the lights came on... the lights came on... the light- OH NO THEY DIDN'T!!! All four failures have been while no channel was in use. As I said above I'll be getting someone in. If anyone appropriately experienced wants to quote please PM me. I'm in Blackpool. Link to comment Share on other sites More sharing options...
Davethsparky Posted January 1, 2009 Share Posted January 1, 2009 When you say trip do you mean RCD or MCB or RCBO? Link to comment Share on other sites More sharing options...
Johnno Posted January 1, 2009 Author Share Posted January 1, 2009 It's the circuit breaker on the final circuits distribution board. I don't know what type it is. None of the channel trips on the Chilli have blown. Link to comment Share on other sites More sharing options...
Tomo Posted January 2, 2009 Share Posted January 2, 2009 Is it an RCD? Look at the breaker - does it have a "Test" button? What is written on the breaker? Many dimmer systems put a fair bit of current (10-20mA) down the earth, due to the suppression caps required for EMC.This can be enough to trip RCDs, although usually at power-up or under load. Link to comment Share on other sites More sharing options...
Davethsparky Posted January 2, 2009 Share Posted January 2, 2009 He has already answered that it is a circuit breaker which is dropping out, so it isn't going to be an earth leakage. THis sounds like one of those faults you're unlikely to be able to find unless you happen to be there when it occurs. Does it always happen in the interval? is it possible that some muppet is turning it off? Link to comment Share on other sites More sharing options...
smalljoshua Posted January 2, 2009 Share Posted January 2, 2009 When I read the O/P I read it as the trip actually breaking/failing to be able to be reset. Is that correct Johnno? Josh Link to comment Share on other sites More sharing options...
Tomo Posted January 3, 2009 Share Posted January 3, 2009 He has already answered that it is a circuit breaker which is dropping out, so it isn't going to be an earth leakage.He said that he doesn't know what type it is.You and I can probably spot most types of breaker a mile off, but not everyone can! Another other possibility is that it's heat related. Standard MCBs are thermally-operated, which means that they trip out quicker when they're warm. You'll need to do some proper investigation to find this. Are you sure that the Chilli is the only thing on this breaker?Could there be something else fed from it?Could the Chilli have an intermittent short-circuit fault? Dave's right though - it's very hard to find out what's happening unless you see it occur. Link to comment Share on other sites More sharing options...
Johnno Posted January 3, 2009 Author Share Posted January 3, 2009 Thanks for your interest. AFAIK the breaker is an ordinary MCB (I'm off work 'til Tuesday so I can't check). There are no test buttons. AFAIK there is nothing else on that circuit. The stage distribution is modern and unlikely to have legacy wiring. If it does I've no idea what else it might feed. Each failure has occurred when no lights were on and caused the MCB to drop out. Resetting it was not a problem. Seeing the fault occur is unlikely to happen given that it occurs when nothing is happening. I don't envy the engineer! Link to comment Share on other sites More sharing options...
PoppaDom Posted January 3, 2009 Share Posted January 3, 2009 My initial thought here is a tired MCB. Sounds bizarre but I have come across a number over the years that become sensitive with age... Dom Link to comment Share on other sites More sharing options...
Davethsparky Posted January 3, 2009 Share Posted January 3, 2009 Thanks for your interest. Each failure has occurred when no lights were on and caused the MCB to drop out. Resetting it was not a problem. Are you sure it dropped out when no lights were on or could it have gone at the moment that you switched the lights on? It could be in-rush related if this is the case. I have had this happen with security lighting before where the breakers dropped out when the lights were really cold and they were switched on, worked fine once they got a little warmth into them. My apologies to Tomo, I thought that when he said It's the circuit breaker on the final circuits distribution board. I don't know what type it is.he meant that he didn't know if it was B,C or D type. Link to comment Share on other sites More sharing options...
Johnno Posted January 4, 2009 Author Share Posted January 4, 2009 I can't say if it's inrush related or not. All I can tell you is that the lights worked for the first half of our show - 45 mins - and did not work at all when the curtain opened for the start of the second act: on inspection the circuit breaker was then found to be out. It's in a locked box in the wings in full view of everyone, so no tampering suspected. The trip was reset and the second half proceeded normally (1 hour with a lot of flashing in the last 5 minutes) If the failure is heat related why last the whole performance? Yes, it could have failed at the point of switching on but there were plenty of blackouts during the show and none of them caused problems. The second recent failure was a dance performance in assembly. The only state required was preset and tested, and then mastered off. On cue the boy turned up the master and absolutely nothing happened so the show was played out to the auditorium lights - a bit dreary! In both cases the total load was about 11kW across 15 or so channels. Barely enough to light a cigarette never mind a stage! The unit is about 8 years old and very lightly used, both in frequency and load. When I get back to work I'll contact Zero88 for advice or service. I feel a call out charge coming on ;) Edit: Last line added Link to comment Share on other sites More sharing options...
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