Outdoor event

[simon1969]

Hi Guys

Just wondered if anyone has had problems with amplifiers
when they have done an outdoor event,powered by a generator?
My amp kept cutting out when I was using it is this anything to do with power surges from a generator?

Thanks in advance .

[djeddie]

Firstly, I take it that it was a petrol genny? (i.e. the kind of thing from Machine Mart). They never give the power you're expect, you have to take account of power factor correction and other bits such as that. Always work out KVA rather that Watts. The other thing that can cause a problem is a lot of modern PSU's are switch-mode and they need a good earth, so was the genny earthed correctly, with a proper earth spike?
Anytime I've had no other choice than to run from a petrol genny I've always added a 500W halogen light (that's is on ALL of the time) as it helps settle the genny.
If you have to do it again go for a diesel genny from a proper supplier.

[rth_discos]

Generators come in lots of different flavours.

The small portable ones are rarely sufficient for anything other than a small pa system.

What generator were you using?

[yourdj]

Not ever had a dodgy generator, but I tend to work in decent marquees with big desiel ones. i have one of these in the garage, which can run for a bit in the even of a power issue. The battery is dead mind you but I am reliably informed that they do a reasonable job, especially with sound limiters and digital PA that will not draw much power.

18584

https://www.ebuyer.com/113906-apc-back-ups-240-watts-400-va-input-230v-output-230v-be400-uk?mkwid=sqGZj2Qfp_dc&pcrid=51482427059&pkw=&pmt=&gclid=Cj0KCQjwuYTYBRDsARIsAJnrUXC7E0rC-DzclKIUmIcQLFxFDzDH-f9ujh-yF4lO5nUu0UoNga06ymcaAmPZEALw_wcB

[simon1969]

Hi

It was a big deisel generator powering lights etc (it was a wedding) .
The band were powered with that never had problems with this amp before I will take it to be checked out it didn't seem to be overheating warning light didn't come on.

[djeddie]

As it was a diesel, and presumably from a decent supplier, the next question is what amp was it? (Make and model).

[Excalibur]

Firstly, I take it that it was a petrol genny? (i.e. the kind of thing from Machine Mart). They never give the power you're expect, you have to take account of power factor correction and other bits such as that. Always work out KVA rather that Watts. The other thing that can cause a problem is a lot of modern PSU's are switch-mode and they need a good earth, so was the genny earthed correctly, with a proper earth spike?
Anytime I've had no other choice than to run from a petrol genny I've always added a 500W halogen light (that's is on ALL of the time) as it helps settle the genny.
If you have to do it again go for a diesel genny from a proper supplier.

Hard to disagree with that. :approve:

Toby's idea of an UPS seems logical, and since it's main purpose in life would be power smoothing, then I assume a fairly small one could suffice.

Since we now know it's a big diesel genny, as Eddie has said above, the amp itself is the next place to look. A well respected colleague was having kittens this weekend, because he had to run his switch mode amps from a generator, and he feared for their safety.

[yourdj]

Toby's idea of an UPS seems logical, and since it's main purpose in life would be power smoothing, then I assume a fairly small one could suffice.

I don't think it would last long though, a 15 inch battery speaker would be the best back up (one charging as ones playing). Its not ideal but better than silence and a crying bride. I almost bought a petrol generator the other day as that would be dead handy if for any reason you had a blackout or were camping. the honda ones are near silent now, so perhaps at least that should power the vitals??

This spurred me to order a battery today as my UPS been sat in the garage for 2 years (only cost me £15). I will bring it to every marquee, dodgy house mains supplied marquee I go too just in case. One of my DJ's Martin always has one (same make and model) on his kit and swears by it. He has a £7K Nexo rig and I guess it runs that for a limited amount of time?

If your using analogue amps, then perhaps its worth looking at going digital? Were you drawing voltage from other things especially halogen lighting and haze machines etc. as thats normally the problem. Perhaps the kitchen ovens were on or the halogen festoon lighting outside switched on etc?? What was the breaker box. Sorry for the questions, but when i have any marquee event (especially in a garden) I dod a reccee and the first thing I look at (after access) is the electrics and lighting controls.

My suspicion is that this might be buffet (ovens - assuming not gas) and when it started to get dark (lighting). Bar fridges/coolers?? :)

[simon1969]

As it was a diesel, and presumably from a decent supplier, the next question is what amp was it? (Make and model).

Not sure will check but I spoke to my guy who fixes my equipment and he says it probably was the converter that breaks power to AC ?? As at end of night the amp was fine because less things were being powered from Genny.

[Excalibur]

Toby's idea of an UPS seems logical, and since it's main purpose in life would be power smoothing, then I assume a fairly small one could suffice.




I don't think it would last long though, a 15 inch battery speaker would be the best back up (one charging as ones playing).
You misunderstand, Toby. I'm not talking about it running the night when the power goes off, but simply for it to take out any nasties from an errant generator, and in the case of a cut, to allow you a controlled switch off.


Not sure will check but I spoke to my guy who fixes my equipment and he says it probably was the converter that breaks power to AC ?? As at end of night the amp was fine because less things were being powered from Genny.
Aha! And there we may have the answer. Sadly, Toby may easily have guessed correctly earlier.


My suspicion is that this might be buffet (ovens - assuming not gas) and when it started to get dark (lighting). Bar fridges/coolers?? :)

It's possible that the load on the generator was too high, and caused the voltage to drop, which your amp didn't like. I don't know if switching amps are voltage sensitive. It certainly sounds an interesting problem.

[yourdj]

Sadly, Toby may easily have guessed correctly earlier.


There is always a first for something. :)

Being AC it would not be that your too far away from the generator, so it was probably just the load on it. Chances are they have a few microwaves in the kitchen or a load of toilets all using the hand dryers at once, something like that. Looks at what your amp draws and consider a different system for marquees perhaps? Class D as I have said would be my first choice: https://www.thomann.de/gb/the_tamp_d4500.htm. Also add up all the other kit you have and take out the power hungry lights etc. :)

[simon1969]

You misunderstand, Toby. I'm not talking about it running the night when the power goes off, but simply for it to take out any nasties from an errant generator, and in the case of a cut, to allow you a controlled switch off.


Aha! And there we may have the answer. Sadly, Toby may easily have guessed correctly earlier.



It's possible that the load on the generator was too high, and caused the voltage to drop, which your amp didn't like. I don't know if switching amps are voltage sensitive. It certainly sounds an interesting problem.

Yes that's what I was advised never had that problem before guy told me it probably has a cheap convertor.
Anyway thanks fortunately noone noticed .