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[Mike Monte]

I was at a local outdoor event yesterday where the stage (DJ w/PA) was powered by a Predator 4000 generator.

During the course of the day an aggressive rainstorm came through around 5:00pm.
The stage was covered and the speakers, rack, etc. were bagged/tarped.  The generator kept running out in the open in torrential rain for about 30 minutes with no noticeable ill-effect.

The PA (DJ music plus announcements) kept going throughout the rain storm and thereafter, through the end of the event @ 11:30pm.

I just read-up on the Predator's manual and it doesn't mention anything about running the unit in inclement weather, however, it does recommend keeping the electrical connections dry...

I realize that operating a genny in the rain may not a good practice.

Has anyone else ever had an instance where they had to use a portable generator in the rain for PA use or other?




 
 

[Taylor Hall]

We got a small pop up tent to cover (heyooo) just this scenario. With the legs fully collapsed, it stands about 2ft off the ground which gives plenty of clearance for the gennies underneath. I think it was a 3x5 or 4x6 pop up? Pretty sure we got it at wal mart and was cheap insurance for our screen on the green events.

[Scott Holtzman]

I was at a local outdoor event yesterday where the stage (DJ w/PA) was powered by a Predator 4000 generator.

During the course of the day an aggressive rainstorm came through around 5:00pm.
The stage was covered and the speakers, rack, etc. were bagged/tarped.  The generator kept running out in the open in torrential rain for about 30 minutes with no noticeable ill-effect.

The PA (DJ music plus announcements) kept going throughout the rain storm and thereafter, through the end of the event @ 11:30pm.

I just read-up on the Predator's manual and it doesn't mention anything about running the unit in inclement weather, however, it does recommend keeping the electrical connections dry...

I realize that operating a genny in the rain may not a good practice.

Has anyone else ever had an instance where they had to use a portable generator in the rain for PA use or other?

That generator is not acceptable to use with electronics.  Inverted generators are the standard for small production use.

[Lyle Williams]

I have never seen a generator that wasn't ok to be in the rain.

[Rob Spence]

That generator is not acceptable to use with electronics.  Inverted generators are the standard for small production use.

Not acceptable to whom?

As long as the voltage stays pretty constant and the load is appropriate, what is wrong?

Pretty much everything in the MI world has switching power supplies producing DC so small voltage fluctuations are fine.

[Scott Holtzman]

Not acceptable to whom?

As long as the voltage stays pretty constant and the load is appropriate, what is wrong?

Pretty much everything in the MI world has switching power supplies producing DC so small voltage fluctuations are fine.

Was one of the first things I learned here.  You can hear the governors lag on construction generators whenever the load changes.  I do agree SMPS's can tolerate a wide range of voltage but I know that the power amps in the Yamaha DSR's will reboot on voltage drops.

The answer to your question is both in my experience and group wisdom has always recommended inverter generators. 

Did I miss a memo?

[Paul G. OBrien]

The answer to your question is both in my experience and group wisdom has always recommended inverter generators. 

Did I miss a memo?

In another generator thread recently the same question was raised and it seems the opinion of the electrical experts was that any decent quality generator would be good and that mirrors my experience, I have been using small non inverter generators(5-6kw) at events for the last few years with no problem. The equipment being powered included toroid and smps rack amps, modern EV powered speakers and digital desks and PA processors. Interestingly the only event I had problems at was using inverter generators but in that case I now believe they were undersized for the job.

As for the question of rain protection for the generator, we got rain this year at the Carivibe parade and the sight of the electrical connections at the generator getting wet made me uncomfortable so I suspended a small tarp over it. I don't know if this was technically necessary but it made me feel better.

[Steve M Smith]

Not acceptable to whom?
Pretty much everything in the MI world has switching power supplies producing DC so small voltage fluctuations are fine.

Agreed.  Waveform shape not too important either.


Steve.

[Stephen Swaffer]

In another generator thread recently the same question was raised and it seems the opinion of the electrical experts was that any decent quality generator would be good and that mirrors my experience, I have been using small non inverter generators(5-6kw) at events for the last few years with no problem. The equipment being powered included toroid and smps rack amps, modern EV powered speakers and digital desks and PA processors. Interestingly the only event I had problems at was using inverter generators but in that case I now believe they were undersized for the job.

As for the question of rain protection for the generator, we got rain this year at the Carivibe parade and the sight of the electrical connections at the generator getting wet made me uncomfortable so I suspended a small tarp over it. I don't know if this was technically necessary but it made me feel better.

Since the NEC requires "weatherprrof while in use" covers on installed receptacles, I assume there have been some incidents that triggered that change.  Protecting those connections is certainly a good idea-as long as you take into consideration venting and "hot" surface considerations on the genny.  A vinyl tarp against a muffler might not end well!

[Rob Spence]

In another generator thread recently the same question was raised and it seems the opinion of the electrical experts was that any decent quality generator would be good and that mirrors my experience, I have been using small non inverter generators(5-6kw) at events for the last few years with no problem. The equipment being powered included toroid and smps rack amps, modern EV powered speakers and digital desks and PA processors. Interestingly the only event I had problems at was using inverter generators but in that case I now believe they were undersized for the job.

As for the question of rain protection for the generator, we got rain this year at the Carivibe parade and the sight of the electrical connections at the generator getting wet made me uncomfortable so I suspended a small tarp over it. I don't know if this was technically necessary but it made me feel better.

I think the key thing here is how much headroom you have with the generator (and sound system).
If you are too close to the limit you are going to get excessive voltage swings.
It may be that you can load an inverter unit more than a similar rated conventional unit without undo issues.

[Tim McCulloch]

I think the key thing here is how much headroom you have with the generator (and sound system).
If you are too close to the limit you are going to get excessive voltage swings.
It may be that you can load an inverter unit more than a similar rated conventional unit without undo issues.

When the inverter is out of current, it's out.  What the control circuit does determines how graceful the recovery.  Long term, if the batteries can't be charged faster than the current is drawn, it's over even if you can keep the inverter circuit from failing.

Abrupt and significant changes in loading a diesel powered spinner has both voltage and line frequency impact.  The inertia in a big rotating mass helps, but this is why load banks accompany some types of generator usage.  Kind of analogous to "phantom loading" for resistance plate dimmers back in a previous century...

We spec a minimum generator of 20kW MQ for most events without PoCo service. 

[Jonathan Johnson]

In another generator thread recently the same question was raised and it seems the opinion of the electrical experts was that any decent quality generator would be good and that mirrors my experience...

The problem with small non-inverter generators (maybe <7.5kVA?) is that they don't handle sudden load changes well due to their relatively small rotating mass. If the load change is great enough (as might happen with a large bass thump), the frequency and voltage could be driven outside of the operational limits of the connected equipment. Nobody cares if a skilsaw takes a little longer to get up to speed because the generator slowed down, but it can cause electronics to reboot.

The larger generators have greater mass (and engine torque) which helps them to regulate frequency and voltage, so “inverter” technology isn't as necessary.

If you can minimize the load changes, a small standard genny might work OK.

There could be issues with floating neutral (not bonded to ground) or interconnects with separately-powered devices, but there ways of dealing with that.

[Rob Spence]

The problem with small non-inverter generators (maybe <7.5kVA?) is that they don't handle sudden load changes well due to their relatively small rotating mass. If the load change is great enough (as might happen with a large bass thump), the frequency and voltage could be driven outside of the operational limits of the connected equipment. Nobody cares if a skilsaw takes a little longer to get up to speed because the generator slowed down, but it can cause electronics to reboot.

The larger generators have greater mass (and engine torque) which helps them to regulate frequency and voltage, so “inverter” technology isn't as necessary.

If you can minimize the load changes, a small standard genny might work OK.

There could be issues with floating neutral (not bonded to ground) or interconnects with separately-powered devices, but there ways of dealing with that.

I am curious... where does the inverter generator get the instant energy for a bass drum hit? It has a rather smaller rotating mass.
I agree it will maintain frequency.

[Marc Sibilia]

I am curious... where does the inverter generator get the instant energy for a bass drum hit? It has a rather smaller rotating mass.
I agree it will maintain frequency.

It can use the energy stored in the capacitor bank between the generator and the inverter.  It can also pull more current from its generator windings and slow down even more than a syncronous generator, using the rotational kinetic energy without varying the output frequency.

[Mike Sokol]

I am curious... where does the inverter generator get the instant energy for a bass drum hit? It has a rather smaller rotating mass.
I agree it will maintain frequency.

Inverter generators are actually DC generators that make about 12 volts DC (IIRC). So yes, there's a capacitor to take the current hit. Some of the Yamaha's actually had a small 12-volt battery in the circuit to act as a "super capacitor" of sorts. This also allows them to idle back with reduced loads. Then all the capacitor/battery needs to do is supply enough extra current for a few seconds, which allows the gasoline engine to come up to full RPM, and make full current.

[Brian Hancock]

Using generators in the rain is perfectly fine provided safe cabling practices and elevation from standing water you will see movie sets, commercial shoots, large scale concerts etc etc etc all on generators... the real issue here is appropriately oversizing your generator for the purpose and draw it's being used for ... most generators large dino squishers are 80% power factor corrected meaning you dont get 100% of the x number of listed kw this is typically in a constant draw situation not a fluctuating load ... and some things are more forgiving... par cans dont care ... power amps yes in many situations do.

You can just scale this appropriately so if you have a 1800w powered speaker you probably shouldn't use a 2000w generator but if you have 3 575 pars probably be ok 

[Jerome Malsack]

unless I have missed it,  Most outlets feeding to outside house or basement are on GFI.   So should the Generator have the same GFI protection especially in the rain ?  And most of the cables are basic edison without  RV or moister protection. 

[Stephen Swaffer]

GFCI protection outdoors and around water is always a good idea.  A lot of guys (and gals) -myself included-are reluctant to use GFCI on mission critical circuits.  I am more willing to do it these days-maybe because GFCI reliability has improved-and maybe because age has caused me to value safety over lack of embarrassment. (could be that I've crashed enough on my own that something I can genuinely blame on something else is a relief too)!

[Craig Hauber]

dino squishers

Is this an autocorrect from "dynamo" or something?

[Tim McCulloch]

Is this an autocorrect from "dynamo" or something?

Dinosaur, as in liquid hydrocarbon pumped from the swamps of history.  I presume the "squish" refers to diesel ignition.

[ProSoundWeb Community]