Crown XTI Clipping early

[bobalobus]

Hello

 

So I've had a rack of Crown XTI 4000 (4) for around two years now, and they have been faultless

 

But yesterday doing a small outdoor gig the power was from a generator, I had my normal 32a feed and check with the guys that the generator had AVR

 

But whenever I turned the system up, the clip lights would come on and after 30 seconds or so the amps would shutdown and reboot, the signal would maybe make the -20 light before this happened,

 

Has anyone had a similar problem/ know why this maybe

 

thanks

 

bob

[Rob_Beech]

Generally Over voltage. These things don't tend to suffer from too few of those "volt things" as they're happy down to about 80V. We've found issues with V's above about 255 causing them to do this, and also just switch off. Pain in the arse really on generator supplies. I think this may be the generator coming off load suddenly if the avr isn't quick enough.

 

It's difficult to tell. This could also be a cycle thing, if the increased load is dropping the cycle too much, or the compensation is causing it to go too high. Just because a generator has fancy stuff to keep things inline doesn't mean its working. A local company I work with lost several hundred pounds of stuff through a faulty avr board on a generator about 18 months ago. Put a load on it and the compensation is incorrect and send the voltage through the roof. Lost a dozen par lamps, and a sony rack mount cd player, and it took the fuses out in 5 LA audio graphics but the graphics themselves survived. Nothing else was connected at the time, lucky escape.

 

Was it a "good" generator?

[fincaman]

Hello

 

So I've had a rack of Crown XTI 4000 (4) for around two years now, and they have been faultless

 

But yesterday doing a small outdoor gig the power was from a generator, I had my normal 32a feed and check with the guys that the generator had AVR

 

But whenever I turned the system up, the clip lights would come on and after 30 seconds or so the amps would shutdown and reboot, the signal would maybe make the -20 light before this happened,

 

Has anyone had a similar problem/ know why this maybe

 

thanks

 

bob

 

Hello, I have an XTi 4000 and have had similar problems. Here in Spain low voltage is a consistent problem which is why I bought the XTi, the spec said 100-240 volts but what that means is it will work on 100 or 240 volts not 100 to 240 volts. I have a similar problem to you,as the voltage drops first the clip lights come on then the sound cuts out. In my opinion your problem can be caused by one of two things. Firstly the you say it happens "when you turn it up" so I suspect the generator can't supply the current or can't supply it quickly enough, secondly the waveform from the generator is not a good enough sine wave which can cause all sorts of problems on all sorts of equipment. I am going to buy an inverter generator, (Kipor are good value) The other thing you can do is set your limiters on your amps to a greater - value or just simply turn down the level controls, I know this is not ideal but it's better than loss of sound.

One thing that I have not tried but am going to is to take an earthing rod and try earthing the generators because if you think about it all your screened cables are floating and could be causing HF oscillation, this could be happening when you turn you sliders up so your amps will be delivering maximum power at an inaudible frequency (very dangerous to speakers) and might be asking for to much current from the generators.

 

Good Luck

 

Kevin

 

[quote name='Rob_Beech' timestamp='1319400449' post='414406These things don't tend to suffer from too few of those "volt things" as they're happy down to about 80V.

 

 

Hello Rob, I can't agree on this, My XTi 4000 when booted on 230 v will not work on less than about 185 volts.

 

Regards

 

Kevin

[mallyJJ87]

Could it be that the generator is running a low % output? Does the problem only occur with this generator or does it now happen every time you give it the beans? Just ruling out any possible component issues within the amp which could cause it to be clipping and tripping out. Also, I thought all generators had to have an earthing rod for safety reasons? Any sparkies about to confirm/reject this?

[bobalobus]

Hey thanks for the good responses

The generator is just a small Briggs and Stratton 9kva

Still have it as the guys havnt collected it yet, so I decided to build the whole system again today, to my annoyance the system worked without a problem, so what happened I still don't know

Would be interested to know about the earth rod as we did not have one the other day,

Thanks Bob

[fincaman]

Hey thanks for the good responses

The generator is just a small Briggs and Stratton 9kva

Still have it as the guys havnt collected it yet, so I decided to build the whole system again today, to my annoyance the system worked without a problem, so what happened I still don't know

Would be interested to know about the earth rod as we did not have one the other day,

Thanks Bob

 

Generators don't have one side of the output earthed as the mains does but often one side of the output is connected to the metal parts and it is this that can be earthed. Go to an electrical supplies and buy an earth rod connect a 2,5 mm flexible cable to it (clamp or solder) if the generator hasn't got an earth terminal connect the wire to the earth of your system. Knock the earth rod partly into the ground, all the screens on your cables should be now at earth potential which may help.

 

Regards

 

Kevin

[Darkness]

I've had an XTI for a few months now and it has worked great except for 1 show during the summer when I was running of a generator. It was fine when I was playing ambient music but as soon as I turned it up to do a performance the clipping lights came on constant and the amp kept cutting out, I don't think I was pusshing it any more than usual, I even tried turning everything down a little but it still done it, I put it down to running off a generator.

[fincaman]

Hello Again, I think the conclusion is that you have to be careful when using generators, I used my XTi on a Honda inverter generator with great results, on the same show my stairville dimmers gave erratic unusable results on a normal generator and this is what prompted me to think about earthing the generator (the next day) but I haven't had a chance to try it since. It was an outdoor event with long DMX cables and if you think about it the screens on the cables were connected to nothing and actually might have been picking up interference and making the problem worse !!! or it could simply be the waveform from the generator that wasn't good enough.

 

Regards

 

Kevin

[Rob_Beech]

The "trigger" shall we say we found was sudden peaks.

 

Say for example we had a keyboard being sent to mix 5, and the keyboard player switched off his keyboard sending a massive signal to it and the amp, the amp would switch off, as if you'd unplugged the power, switching the power switch off and on would reset the amp. If the keys were going to say mix 1 and 2 aswell, that amp too would go. And it didn't have to be this, it could be some idiot accordian player unclipping a ATM35 from his instrument and throwing it on the floor etc etc...

 

And we've succenfully run on 230v, 100-110 volts, and about 160, (don't ask)