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Title: Generator suggestions
Post by: Dave Guilford on June 09, 2019, 05:35:58 pm
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series.  They use the 50amp California connectors to a spider box.  I know my rig works on 50amps. I suspect less, but I always try to get as much power allocated to me as possible.

That said/ Iíve been generator shopping for years.  Tow behind style would be dynamite but Iím at the level where Iím ready to drop $15k on a generator.

I want inverter of course.  And ideally Iíd like to get up to 50+ amps at 120v

Iíve seen a bunch of the smaller Home Depot type where you can link them for extra power.  Bonus points is that means 2 smaller ones for gigs that need them. Not often, but nice peace of mind.

Suggestions??
Title: Re: Generator suggestions
Post by: Mike Monte on June 09, 2019, 07:02:04 pm
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series.  They use the 50amp California connectors to a spider box.  I know my rig works on 50amps. I suspect less, but I always try to get as much power allocated to me as possible.

That said/ Iíve been generator shopping for years.  Tow behind style would be dynamite but Iím at the level where Iím ready to drop $15k on a generator.

I want inverter of course.  And ideally Iíd like to get up to 50+ amps at 120v

Iíve seen a bunch of the smaller Home Depot type where you can link them for extra power.  Bonus points is that means 2 smaller ones for gigs that need them. Not often, but nice peace of mind.

Suggestions??

I own a Honda eu3000is inverter generator.  According to the specs it puts out 23 amps.
I have done local outdoor rock shows with it powering a 3-way rig, four monitors, and back line.
 
I have the parallel cables to pair it with another similar unit (which my local Home Depot rents for $50.00 per day).

I know that you are looking for 50+ amps but a couple of the above units in parallel (46 amps) should power a sizable show.

Others will chime in with what they use...


btw: I also use my unit to power my home (via a ProTran switch panel) during storm outages.


Title: Re: Generator suggestions
Post by: Scott Holtzman on June 10, 2019, 12:28:21 am
I own a Honda eu3000is inverter generator.  According to the specs it puts out 23 amps.
I have done local outdoor rock shows with it powering a 3-way rig, four monitors, and back line.
 
I have the parallel cables to pair it with another similar unit (which my local Home Depot rents for $50.00 per day).

I know that you are looking for 50+ amps but a couple of the above units in parallel (46 amps) should power a sizable show.

Others will chime in with what they use...


btw: I also use my unit to power my home (via a ProTran switch panel) during storm outages.

For 1/2 that you can get an MQ Power Whisperwatt 7Kva.  For years I thought the Honda was the top of the line, while not an inverter generator this is a baby version of the Whisperwatt units you see at all sorts of outdoor production.  The flywheel is sized right and the diesel engine will run forever.

DA7000SSA2 are about 6500 delivered to your door.

Title: Re: Generator suggestions
Post by: Steven Cohen on June 10, 2019, 09:30:06 am
David,

Honda has their new EU7000i inverter generator. Its the most powerful consumer inverter generator, it does 120/240, and the only one that uses fuel injection, which I ASSume will have less fuel clogging issues and perhaps better fuel economy. Here is a link,

https://powerequipment.honda.com/generators/models/eu7000is.

Scott's idea of the MQ Power Whisperwatt 7Kva is a good one. If I had it to do all over again I would consider a 1500 RPM, water cooled diesel.

 
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series.  They use the 50amp California connectors to a spider box.  I know my rig works on 50amps. I suspect less, but I always try to get as much power allocated to me as possible.

That said/ Iíve been generator shopping for years.  Tow behind style would be dynamite but Iím at the level where Iím ready to drop $15k on a generator.

I want inverter of course.  And ideally Iíd like to get up to 50+ amps at 120v

Iíve seen a bunch of the smaller Home Depot type where you can link them for extra power.  Bonus points is that means 2 smaller ones for gigs that need them. Not often, but nice peace of mind.

Suggestions??
Title: Re: Generator suggestions
Post by: Dave Guilford on June 10, 2019, 10:28:28 am
Examples of a 1500rmp water cooled Deisel ?
Title: Re: Generator suggestions
Post by: Steven Cohen on June 10, 2019, 10:48:10 am
Dave,

Sorry, 1800 rpm is the standard, not 1500 rpm, although I found 1 1500 RPM. Here are a few examples, but there are many more.

http://www.hardydiesel.com/kubota-generators/kubota-7-kw.html

https://www.whisperpower.com/US/4/38/26/products/generators-sq-series-(low-rpm)/m-sq-8-marine.html

https://www.electricgeneratorsdirect.com/Generac-MLG15/p71667.html

Examples of a 1500rmp water cooled Deisel ?
Title: Re: Generator suggestions
Post by: Robert Piascik on June 10, 2019, 11:15:43 am
I would recommend TWO of the Honda eu7000 and link if you really, really need that much power. I own a eu6500 (the older model) and it kicks ass. Bought mine used for $2600, new I think theyíre about $4k and with two youíd be modular for times you donít need it all. I donít know your rig but I bet it uses less power than you think.
Title: Re: Generator suggestions
Post by: Steve Litscher on June 10, 2019, 12:22:30 pm
I would recommend TWO of the Honda eu7000 and link if you really, really need that much power. I own a eu6500 (the older model) and it kicks ass. Bought mine used for $2600, new I think theyíre about $4k and with two youíd be modular for times you donít need it all. I donít know your rig but I bet it uses less power than you think.

+1

I can't count the number of times I rented the EU7000i for events, and it was always just an incredible performer.

Largest rig I ever ran on it consisted of:

4x JTR Captivator C218Pro subs
2x RCF TTL6-A mains
6x Yamaha DSR112 for monitors
Full backline
Full FOH gear (C3500, CDM32, Lake LM44, Shure wireless, etc)
20x Blizzard Hotbox
4x Blizzard G-Streak
4x Blizzard Blade RGBW
1x Radiance Hazer

No issues at all, and they're so quiet... They are also incredibly fuel efficient. We'd fill them once a day for most gigs. If your gear is relatively new/young, it's far more efficient than we all think.

I remember running 4x JTR Orbit Shifters on a PLD4.5 at what felt like a punishing volume, and the PLD4.5 showed it was pulling 5-5.5 amps.
Title: Re: Generator suggestions
Post by: Frank Koenig on June 10, 2019, 12:48:29 pm
Sorry, 1800 rpm is the standard, not 1500 rpm, although I found 1 1500 RPM. Here are a few examples, but there are many more.

Sorry, it depends on whether you want 50 Hz or 60 Hz. For a synchronous-machine (not inverter) generator there is a fixed relationship between the rotational velocity, number of poles, and the output frequency. --Frank
Title: Re: Generator suggestions
Post by: Steven Cohen on June 10, 2019, 01:06:48 pm
Thanks Frank for the explanation. I had read something similar to your description while I was researching generators before I purchased an inverter type but I had forgotten.

Sorry, it depends on whether you want 50 Hz or 60 Hz. For a synchronous-machine (not inverter) generator there is a fixed relationship between the rotational velocity, number of poles, and the output frequency. --Frank
Title: Re: Generator suggestions
Post by: Frank Koenig on June 10, 2019, 02:21:51 pm
A synchronous generator provides one output cycle per pole-pair per revolution. So for 60 Hz output a 2 pole machine would need to turn 3600 RPM, a 4 pole machine 1800 RPM, a 6 pole machine 1200 RPM, and so forth.

The same relationship roughly holds for conventional induction motors. The difference is that they are not synchronous but run at a "slip speed" so that the output speed is always somewhat less than the synchronous speed (as determined from the input frequency and the number of poles), and depends on the load torque.

In the modern world with cheap and amazing power electronics all this matters a lot less. A great thing for windmills, small engine-driven generators, electric vehicles, and variable speed drives of all sorts.

--Frank
Title: Re: Generator suggestions
Post by: Steven Cohen on June 10, 2019, 02:31:31 pm
Frank,

Your statement of
"In the modern world with cheap and amazing power electronics all this matters a lot less" reminds me of a few weeks ago when I carried down an Itech 4 X 3500hd under one of my arms from a catwalk. I still had my other arm free to hold on to the stair rail.

 
A synchronous generator provides one output cycle per pole-pair per revolution. So for 60 Hz output a 2 pole machine would need to turn 3600 RPM, a 4 pole machine 1800 RPM, a 6 pole machine 1200 RPM, and so forth.

The same relationship roughly holds for conventional induction motors. The difference is that they are not synchronous but run at a "slip speed" so that the output speed is always somewhat less than the synchronous speed (as determined from the input frequency and the number of poles), and depends on the load torque.

In the modern world with cheap and amazing power electronics all this matters a lot less. A great thing for windmills, small engine-driven generators, electric vehicles, and variable speed drives of all sorts.

--Frank
Title: Re: Generator suggestions
Post by: Rob Spence on June 10, 2019, 03:45:18 pm
To the OP, why do you want an inverter unit?
Title: Re: Generator suggestions
Post by: Dave Guilford on June 10, 2019, 04:03:22 pm
To the OP, why do you want an inverter unit?

Theyíre quieter. They came highly recommended. Iíve been using an inverter for 5 years already and always exceptionally happy with it.  Allows me to run pretty much anything Iíll ever need to with piece of mind.
Title: Re: Generator suggestions
Post by: Rob Spence on June 10, 2019, 05:24:06 pm
Theyíre quieter. They came highly recommended. Iíve been using an inverter for 5 years already and always exceptionally happy with it.  Allows me to run pretty much anything Iíll ever need to with piece of mind.

MQ generators are also quiet. The better ones are so quiet you canít hear them 10í away.
Title: Re: Generator suggestions
Post by: Scott Holtzman on June 10, 2019, 07:49:42 pm
MQ generators are also quiet. The better ones are so quiet you canít hear them 10í away.

Agree Rob.  We, like everyone rent a ton of the Honda's and they are great.  The MQ's are basically babies of their big boy units.  They are even more robust, quieter and I know it's a small point but you trailer that bad boy up and the client sees $150 value.  The Honda looks like what everyone else has.

Title: Re: Generator suggestions
Post by: Dave Guilford on June 10, 2019, 08:36:20 pm
Agree Rob.  We, like everyone rent a ton of the Honda's and they are great.  The MQ's are basically babies of their big boy units.  They are even more robust, quieter and I know it's a small point but you trailer that bad boy up and the client sees $150 value.  The Honda looks like what everyone else has.

$150?  Too cheap.  I get $400-500 on a generator when I rent it out!
Title: Re: Generator suggestions
Post by: Dave Guilford on June 10, 2019, 08:45:45 pm
I know of MultiQuip of course.  And Wacker Neuson makes their G series.  Who else mfg similar ones?
Title: Re: Generator suggestions
Post by: Scott Holtzman on June 10, 2019, 10:49:40 pm
$150?  Too cheap.  I get $400-500 on a generator when I rent it out!

You get $400 for a 7kva generator?  Geez I get a 70 delivered for $250

Title: Re: Generator suggestions
Post by: Dave Guilford on June 12, 2019, 02:10:28 pm
No. Local sunbelt / United Rentalís type places get me a 15 for $250 when I pick up and drop off.  I charge clients $400-500
Title: Re: Generator suggestions
Post by: Mike Monte on June 14, 2019, 07:51:23 am
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series. 

Thoughts: 
If renting has worked for you all along, why the need for change?  (You are passing the rental/cartage fee on to your clients, thus "no skin off your teeth" as it stands now.)
How many gigs would it take to cover a new unit's cost?

Owning a tow-behind would be cool, however, storing the unit (when not gigging the unit) comes to mind.  How many outdoor genny gigs will you do during the winter months?

Does the amount of remote work make sense of the purchase?

For me, storing a tow-able generator would be a big issue...

In my local world an eu3000is generator works for most of my applications....and I store it in my garage for home use.   On the few times that I need more power, I rent another one (from Home Depot) and parallel them.

Title: Re: Generator suggestions
Post by: Dave Guilford on June 14, 2019, 09:45:53 am
Thoughts: 
If renting has worked for you all along, why the need for change?  (You are passing the rental/cartage fee on to your clients, thus "no skin off your teeth" as it stands now.)
How many gigs would it otake to cover a new unit's cost?

Owning a tow-behind would be cool, however, storing the unit (when not gigging the unit) comes to mind.  How many outdoor genny gigs will you do during the winter months?

Does the amount of remote work make sense of the purchase?

For me, storing a tow-able generator would be a big issue...

In my local world an eu3000is generator works for most of my applications....and I store it in my garage for home use.   On the few times that I need more power, I rent another one (from Home Depot) and parallel them.

Storage isnít a big issue for me.

On average, I rent approx 10-12 times per summer, at $250-300 a pop (weekends are more). All in all, I spend about $3000 per summer.  After 5 years now that means Iíve spent $15k. 

As far as my wallet knows, Iíve already bought one, but have nothing to show for it !

I foresee myself doing this for another 10-20 years. 

As for eu3000- I need, at minimum, 40 amps at 120v. 
Title: Re: Generator suggestions
Post by: Mike Monte on June 14, 2019, 11:01:47 am
Storage isnít a big issue for me.

On average, I rent approx 10-12 times per summer, at $250-300 a pop (weekends are more). All in all, I spend about $3000 per summer.  After 5 years now that means Iíve spent $15k. 

As far as my wallet knows, Iíve already bought one, but have nothing to show for it !

I foresee myself doing this for another 10-20 years. 

As for eu3000- I need, at minimum, 40 amps at 120v.

As with any large purchase, I am sure that you have thought this through before your purchase.
Your plan to be "in the game" for another 10-20 yrs makes sense for you to own..
Title: Re: Generator suggestions
Post by: Ray Aberle on June 14, 2019, 09:23:12 pm
Don't kill me, but we bought our 45kW second hand in May 2012 for $6,500. There are deals to be had, if you look in the right places.
Title: Re: Generator suggestions
Post by: Dave Guilford on June 14, 2019, 09:39:29 pm
Don't kill me, but we bought our 45kW second hand in May 2012 for $6,500. There are deals to be had, if you look in the right places.
Excellent!  What sort of places would you recommend?
Title: Re: Generator suggestions
Post by: Tim Hite on June 15, 2019, 02:27:34 am
Aggreko
Associated Power
Star Power

All take good care of their rentals.

My dad bought a 60kW Cummins/Onan Genset for $4000 from a hospital that was switching out  its backup generator . It had 43 hours on it and had been regularly serviced. Came with switchgear, too.

Excellent!  What sort of places would you recommend?
Title: Re: Generator suggestions
Post by: Mike Monte on June 26, 2019, 07:19:17 am
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series.  They use the 50amp California connectors to a spider box.  I know my rig works on 50amps. I suspect less, but I always try to get as much power allocated to me as possible.

That said/ Iíve been generator shopping for years.  Tow behind style would be dynamite but Iím at the level where Iím ready to drop $15k on a generator.

I want inverter of course.  And ideally Iíd like to get up to 50+ amps at 120v

Iíve seen a bunch of the smaller Home Depot type where you can link them for extra power.  Bonus points is that means 2 smaller ones for gigs that need them. Not often, but nice peace of mind.

Suggestions??

FWIW: When this thread started (on 6/15) I vaguely remembered an issue I had with a large (tow behind) diesel generator.

Peaking my interest, I found my notes from that particular gig 8 years ago.  BTW: It was prior to when I bought my Fluke multimeter...

I was tech'ing an outdoor show in my town where the stage power was supplied by a large tow-behind generator.
Everything on my end (sound and lights) ran fine from the generator except for the Crown XTI4000 amp in my rack...  On power-up, the amp kept indicating "fault" on the screen...while my xs4300 and IT8000 amps were fine. 
This was prior to the festival during the morning, thus no lights were in use.

Trying to check the issue, I ran a power cord to a "hard-wired" outlet and the amp started right up with no issues. 
I did the show as such for the rest of the day/evening without further power issues.

I suspect the XTI amp to be finiky....

Running that same rig on my Honda inverter generator = zero issues.




 
 
Title: Re: Generator suggestions
Post by: Debbie Dunkley on June 26, 2019, 09:40:40 am
Every time I have used either Honda Inverters or my own Yamaha Inverters, I have had zero issues. On the 2 occasions I have been provided diesel Whisper Watt units, they have worked but my UPS HATES them and will continually switch back and forth from mains to battery so I have to eliminate the UPS from the chain.
Title: Re: Generator suggestions
Post by: Frank Koenig on June 26, 2019, 11:43:15 am
On the 2 occasions I have been provided diesel Whisper Watt units, they have worked but my UPS HATES them and will continually switch back and forth from mains to battery so I have to eliminate the UPS from the chain.

Debbie, I find this surprising. A properly functioning big diesel should provide about the cleanest power you can get since there aren't any other non-linear loads to contaminate the power as there are with the line. I bet the voltage regulator was out of adjustment or kaput, the frequency was way off, or there was some ground/neutral/God-knows-what wiring issue causing the problem. Did they rent you the same funky generator both times? I once rented a big diesel from Cresco (to run a welder, not sound equipment) and it was pretty out of whack voltage-and frequency-wise. --Frank
Title: Re: Generator suggestions
Post by: Tim McCulloch on June 26, 2019, 11:55:30 am
Every time I have used either Honda Inverters or my own Yamaha Inverters, I have had zero issues. On the 2 occasions I have been provided diesel Whisper Watt units, they have worked but my UPS HATES them and will continually switch back and forth from mains to battery so I have to eliminate the UPS from the chain.
Sounds like a line frequency problem due to a broken or misprogramed voltage/speed regulator.
Title: Re: Generator suggestions
Post by: Debbie Dunkley on June 26, 2019, 05:13:46 pm
Debbie, I find this surprising. A properly functioning big diesel should provide about the cleanest power you can get since there aren't any other non-linear loads to contaminate the power as there are with the line. I bet the voltage regulator was out of adjustment or kaput, the frequency was way off, or there was some ground/neutral/God-knows-what wiring issue causing the problem. Did they rent you the same funky generator both times? I once rented a big diesel from Cresco (to run a welder, not sound equipment) and it was pretty out of whack voltage-and frequency-wise. --Frank

2 different events and 2 different gennies.
The first time I put it down to something being a bit off - like what you refer to or similar but when it happened again it made me think that the big diesel gennies just don't offer as clean power as an inverter.
Like I said the system ran with no issues but I simply could not get the UPS to play ball. The same UPS has NEVER had any other issues using mains or inverters.
Title: Re: Generator suggestions
Post by: Art Welter on June 26, 2019, 05:44:45 pm
2 different events and 2 different gennies.
 The same UPS has NEVER had any other issues using mains or inverters.
Was the same power distribution system used for the two different events?
Title: Re: Generator suggestions
Post by: Debbie Dunkley on June 26, 2019, 06:05:58 pm
Was the same power distribution system used for the two different events?

It was a while ago so I don't really remember the details. I was just left with a bad taste in my mouth both times. I rarely have to use anyone elses generators but my own so it doesn't happen very often.
Title: Re: Generator suggestions
Post by: Dave Guilford on June 26, 2019, 11:57:43 pm
Guys - next step- suggest to me a basic sister solution. I need a California style 50a/240v inlet broken down to 4x 15a 120v circuits.

Racked or standalone box. 
Title: Re: Generator suggestions
Post by: Mark Cadwallader on June 27, 2019, 01:27:01 am
Guys - next step- suggest to me a basic sister solution. I need a California style 50a/240v inlet broken down to 4x 15a 120v circuits.

Racked or standalone box.

LEX and Motion Labs offer UL or ETL listed devices in both flavors, with 20A breakers on the circuits.  Total of six breakers (three per hot leg).   There are others, too, but if the device is not UL or ETL listed, buyer beware. 

CEP makes stand-alone boxes that are widely used in the construction industry in at least two levels of physical protection.  The "roll cage"'version costs more, but is harder to accidently crush.  Construction grade boxes are typically GFCI protected.

I have a 3U rackmount LEX unit in a 3U shockmount rack.
Title: Re: Generator suggestions
Post by: Frank Koenig on June 27, 2019, 11:16:21 am
CEP makes stand-alone boxes that are widely used in the construction industry in at least two levels of physical protection.  The "roll cage"'version costs more, but is harder to accidently crush.  Construction grade boxes are typically GFCI protected.

And, while kind of big and clunky, the construction "spider boxes" have the advantage of being OK to use outdoors where it might rain since the receptacles have little eves over them. (I think they have a 3R rating.) Not so for rack-mount distros. If I made a spider box I would call it the NEMAtoad. -F
Title: Re: Generator suggestions
Post by: Rob Spence on June 27, 2019, 02:33:11 pm
2 different events and 2 different gennies.
The first time I put it down to something being a bit off - like what you refer to or similar but when it happened again it made me think that the big diesel gennies just don't offer as clean power as an inverter.
Like I said the system ran with no issues but I simply could not get the UPS to play ball. The same UPS has NEVER had any other issues using mains or inverters.

The issue is for a given UPS, what does it treat as a power fault and then switch to batteries?

Many units consider a small fluctuation of frequency to be a fault. After all, these are mostly consumer grade units designed for use in a residence where the frequence rarely varies.

Generally, I find that at the level of equipment most weekend warriors use, nothing cares about line frequency except the UPS.

If I have a generator under my control, I donít need a UPS. I do use them with grid power where I canít see my power source.
Title: Re: Generator suggestions
Post by: Jim Layton on June 27, 2019, 03:27:46 pm
I had similar XTi 4K issues when connected to a spider box, powered by a Wacker tow-behind generator. As soon as the band went on, the fault lights lit and output dropped. It was my first outdoor/gen show. I had no idea what was going on. People here suggested it may have been a problem the gen, but now I think it was the XTi amps. I used the same rig on a different generator and zero problems. I now use XTi 6Ks, which are supposed to be similar to the old iTechs. I have not used them with a gen and band situation. Sorry to hijack the post but that experience has always been a curiosity.
Title: Re: Generator suggestions
Post by: Rob Spence on June 27, 2019, 11:50:53 pm
I find that too many times a too small generator is used. They figure they only use 3000 watts so a 3500 watt unit should work when they really need a much larger one to deal with the dynamic load.
Title: Re: Generator suggestions
Post by: Debbie Dunkley on June 28, 2019, 10:40:01 am
The issue is for a given UPS, what does it treat as a power fault and then switch to batteries?

Many units consider a small fluctuation of frequency to be a fault. After all, these are mostly consumer grade units designed for use in a residence where the frequence rarely varies.

Generally, I find that at the level of equipment most weekend warriors use, nothing cares about line frequency except the UPS.

If I have a generator under my control, I donít need a UPS. I do use them with grid power where I canít see my power source.

This might have been the case Rob - simply small fluctuation in frequency. The UPS was switching back and forth very quickly (on both occasions) so whatever it was was happening constantly. I have never witnessed this happen or any switchover to battery on my UPS in any other situation other than complete power failure.
Title: Re: Generator suggestions
Post by: Tim Hite on June 28, 2019, 05:33:05 pm
Capacity balancing is always tricky on the diesel gensets. If the genset is too small you get power fluctuations and if it's too big you get wet stacking. It's even tougher to get it right with nothing but a sound system for a load, since you're be expected to be running 1/8 power or less most of the time with dynamics up to 9/10 power.

I generally go one step up in generator size from my max rated amplifier load, but I'm sure there's a better way to do the selection.


I find that too many times a too small generator is used. They figure they only use 3000 watts so a 3500 watt unit should work when they really need a much larger one to deal with the dynamic load.
Title: Re: Generator suggestions
Post by: Dave Guilford on June 29, 2019, 07:34:11 pm
Just a follow up.  I selected a MQ7000 tow behind generator and expect to pick it up after the 4th of July.

Iíll have to get a distro and some of that 50a California feeder.  Ug. 
Title: Re: Generator suggestions
Post by: Scott Holtzman on June 30, 2019, 05:12:26 am
Just a follow up.  I selected a MQ7000 tow behind generator and expect to pick it up after the 4th of July.

Iíll have to get a distro and some of that 50a California feeder.  Ug.

Great choice.  Give us a full report please.
Title: Re: Generator suggestions
Post by: Frank Koenig on June 30, 2019, 11:13:14 am
Great choice.  Give us a full report please.

Agree -- great choice. It looks like the output overcurrent protection on that model is 30 A so you would only need a 30 A feeder unless you also want to use it with larger generators or "stove plug" line power. It could save a bit of weight (and cost). --Frank
Title: Re: Generator suggestions
Post by: Dave Guilford on June 30, 2019, 12:26:09 pm
Agree -- great choice. It looks like the output overcurrent protection on that model is 30 A so you would only need a 30 A feeder unless you also want to use it with larger generators or "stove plug" line power. It could save a bit of weight (and cost). --Frank

Unsure what means
Title: Re: Generator suggestions
Post by: Frank Koenig on June 30, 2019, 12:39:45 pm
Unsure what means

The feeder cable and downstream distribution need only be sized for the maximum current available from the source. If the source is a 7 kVA generator fitted with 30 A overcurrent protection, as I believe is the case here, then the feeder only needs to be able to handle (and be rated for) 30 A so you can use a smaller wire size and appropriate connectors, NEMA L14-30 in this instance. If you also want to use this same feeder with sources where the current may be as large as 50 A, then you need the 50 A feeder cable with the Cali connectors and adapters to go with your generator.
 
By the way, did you get the mechanical governor (+/- 5%) or plump for the electronic frequency control (+/- .25%)?

--Frank
Title: Re: Generator suggestions
Post by: Tim Hite on June 30, 2019, 02:09:01 pm

By the way, did you get the mechanical governor (+/- 5%) or plump for the electronic frequency control (+/- .25%)?

--Frank

Upholstered in rich, Corinthian leather, no doubt. . .
Title: Re: Generator suggestions
Post by: Dave Guilford on June 30, 2019, 11:40:13 pm
The feeder cable and downstream distribution need only be sized for the maximum current available from the source. If the source is a 7 kVA generator fitted with 30 A overcurrent protection, as I believe is the case here, then the feeder only needs to be able to handle (and be rated for) 30 A so you can use a smaller wire size and appropriate connectors, NEMA L14-30 in this instance. If you also want to use this same feeder with sources where the current may be as large as 50 A, then you need the 50 A feeder cable with the Cali connectors and adapters to go with your generator.
 
By the way, did you get the mechanical governor (+/- 5%) or plump for the electronic frequency control (+/- .25%)?

--Frank

Somewhere earlier it was mentioned that the 50a 240v California connector was essentially turning that into 100a at 120v. 

Why,  on this mq7000, wouldnít the 25a 240 California connectors deliver 50a at 120?

This generator specifies that it can make 50a at 120v.  Thatís what I need - how do I pull all avail power with this genny?
Title: Re: Generator suggestions
Post by: Tim McCulloch on July 01, 2019, 09:11:20 am
Somewhere earlier it was mentioned that the 50a 240v California connector was essentially turning that into 100a at 120v. 

Why,  on this mq7000, wouldnít the 25a 240 California connectors deliver 50a at 120?

The connector does not magically "turn" anything into anything.  It's a connector for a 120/240v service.  This service implies that it's a 240v center-tapped circuit so you get 120v from neutral to either hot leg or 240v from hot to hot.  The total available current does not change.

Quote
This generator specifies that it can make 50a at 120v.  Thatís what I need - how do I pull all avail power with this genny?
Each hot leg is 30 amps, limited by the circuit breaker, and note that a breaker of that rating is on both the Cali connector and the L14-30.
Title: Re: Generator suggestions
Post by: Tim Hite on July 01, 2019, 11:58:19 am
The unit you selected will supply 30 amps at 240 volts, so according to the power law:

30A*240V=7200W

You need a bigger generator. Probably something like 15kW, which is the next size up.

50A*240V=12000W


VxA=P

This ties in to my earlier post about sizing your genset correctly, since you need to be pulling a >40% constant load to avoid wet stacking.

You should really really talk to a generator pro to help you get it right.


Somewhere earlier it was mentioned that the 50a 240v California connector was essentially turning that into 100a at 120v. 

Why,  on this mq7000, wouldnít the 25a 240 California connectors deliver 50a at 120?

This generator specifies that it can make 50a at 120v.  Thatís what I need - how do I pull all avail power with this genny?
Title: Re: Generator suggestions
Post by: Russell Ault on July 01, 2019, 03:58:12 pm
Somewhere earlier it was mentioned that the 50a 240v California connector was essentially turning that into 100a at 120v. 

Why,  on this mq7000, wouldnít the 25a 240 California connectors deliver 50a at 120?

This generator specifies that it can make 50a at 120v.  Thatís what I need - how do I pull all avail power with this genny?

To the best of my knowledge, there's no such thing as a 25 A California connector, they're all 50 A. In this case, the California connector is capable of handling almost twice the power that your generator is actually capable of producing. The NEMA L14-30 is also capable of handling the generator's full power, but allows you to use thinner cable (since, for safety, the cable should be spec'ed to the capabilities of the connectors, even if actual intended usage is lower).

Just to be clear, the current-carrying capacity of all connectors (not just California connectors) is specified per contact, so a 50A California connector means 50 A for each Hot and the Neutral, a NEMA L14-30 is 30 A for each Hot and the Neutral, etc. So for example, a NEMA L14-30 is rated for 30 A of 240 (or 208) V power between the two Hots (called Legs), OR rated for 30 A of 120 V power between each Leg and the Neutral, for a total of 60 A of 120 V, OR some combination of the two (e.g. 10 A of 240 V power and 40 A of 120 V power split evenly between the two legs).

In your case, to access the full 6000 W that you're generator can produce as 50 A of 120 V power you'll need a distro that can take in up to 30 A of 240 V power and break it down into four 20 A 120 V circuits, two for each Leg. Of course, your generator is only actually capable of continuously producing 25 A of power per Leg, meaning that you won't be able to load all four 120 V circuits to 20 A. For example, If one 120 V circtuit is loaded to 16 A, the other 120 V circuit attached to the same Leg will only have 9 A of power left available to it, and attaching a larger load might pop the main breaker on the generator even though you'll be well under the breaker limits on the distro.

-Russ
Title: Re: Generator suggestions
Post by: Dave Guilford on July 01, 2019, 05:43:18 pm
The unit you selected will supply 30 amps at 240 volts, so according to the power law:

30A*240V=7200W

You need a bigger generator. Probably something like 15kW, which is the next size up.

50A*240V=12000W


VxA=P

This ties in to my earlier post about sizing your genset correctly, since you need to be pulling a >40% constant load to avoid wet stacking.

You should really really talk to a generator pro to help you get it right.

Well brad thatís exactly what I was trying to do and it seems Iíve been given lousy info earlier in this thread.

Letís pretend I donít care about mumbo jumbo and I just want to get all 6000w out of this thing.  How do i?
Title: Re: Generator suggestions
Post by: Tim McCulloch on July 01, 2019, 06:45:07 pm
Well brad thatís exactly what I was trying to do and it seems Iíve been given lousy info earlier in this thread.

Letís pretend I donít care about mumbo jumbo and I just want to get all 6000w out of this thing.  How do i?

Full title boogie is 6000w, 7200w is peak load.  Engine performance is also a consideration, with less engine output at higher ambient temps and less output as elevation rises above sea level. MQ specs these at 60įF.  The details are in the owner's manual.

You can use a RacPacģ style device with an L14-30 flanged inlet and a pair of Edison 20 amp duplex outlets on each leg, each pair protected by a 20 amp circuit breaker.

Your amplifiers will be the biggest load on the generator and they present a dynamic load.  I don't know how you use your system (EDM will be much more taxing than an Eagles cover band) but averaged across a couple of seconds live sound current requirements are lower than you might think, but peaks are instantaneous and unforgiving.

Good luck.
Title: Re: Generator suggestions
Post by: Scott Holtzman on July 02, 2019, 05:09:16 am
Well brad thatís exactly what I was trying to do and it seems Iíve been given lousy info earlier in this thread.

Letís pretend I donít care about mumbo jumbo and I just want to get all 6000w out of this thing.  How do i?

What bad advice did you get? You certainly can get 50amps at 120 (6000watts) out of the generator. 

What is your equipment mix?  Is there some 240 and some 120?  Do you have a load chart of what your are trying to connect?

Title: Re: Generator suggestions
Post by: Stephen Swaffer on July 02, 2019, 01:00:25 pm
For years Iíve been renting 15-20kVa generators. Tow-behind type for outdoor concert series.  They use the 50amp California connectors to a spider box.  I know my rig works on 50amps. I suspect less, but I always try to get as much power allocated to me as possible.

That said/ Iíve been generator shopping for years.  Tow behind style would be dynamite but Iím at the level where Iím ready to drop $15k on a generator.

I want inverter of course.  And ideally Iíd like to get up to 50+ amps at 120v

Iíve seen a bunch of the smaller Home Depot type where you can link them for extra power.  Bonus points is that means 2 smaller ones for gigs that need them. Not often, but nice peace of mind.

Suggestions??

I suspect the "bad information" is a result of "Garbage In Garbge Out".  You asked for "50 amps at 120 volts".  That means different things to different people and in different contexts.  As Tim M said, you can get the 6000 watts out of the genny-but you can't run a 6000 watt/120 volt heater out of the genny.  Tim Hite pointed out you can get 30 amps at 240 volts-which also means you can get two times 30 amps at 120 volts. 30 +30 = 60, which is greater than 50.  If you don't need a 50 amp circuit anywhere.  Iy you have a single 120 volt load that requires more than 30 amps, then you are out of luck.

A sound system is not a single, steady load-it is a system of multiple, dynamic loads.  It's not hard-but it does take some effort to get "the maximum" out of a system.
Title: Re: Generator suggestions
Post by: Rob Spence on July 02, 2019, 10:03:17 pm
Hey Tim H, what is ďwet stackingĒ?
I am not familiar with that term.
Title: Re: Generator suggestions
Post by: Chris Hindle on July 02, 2019, 10:34:57 pm
Hey Tim H, what is ďwet stackingĒ?
I am not familiar with that term.

From Wikipedia....
Wet stacking is a condition in diesel engines in which unburned fuel passes on into the exhaust system.[1] The word "stacking" comes from the term "stack" for exhaust pipe or chimney stack. The oily exhaust pipe is therefore a "wet stack".

This condition can have several causes. The most common cause is idling the engine for long intervals, which does not generate enough heat in the cylinder for a complete burn. "Idling" may be running at full rated operating speed, but with very little load applied. Another is excessive fueling. That may be caused by weak or leaky injectors, fuel settings turned up too high or overfueling for the given rpms. Cold weather running or other causes that prevent the engine from reaching proper operating temperature can cause a buildup of fuel due to incomplete burn that can result in 'wetstacking'. [

In diesel generators, it is usually because the diesel engine is running at only a small percentage of its rated output. For efficient combustion, a diesel engine should be run under at least 60 per cent of its rated power output.

It is detectable by the presence of a black ooze around the exhaust manifold, piping and turbocharger, if fitted. It can be mistaken for lubricating oil in some cases, but it consists of the "heavy ends" of the diesel fuel which do not burn when combustion temperature is too low. The heavier, more oily components of diesel fuel contain more stored energy than a comparable quantity of, say, gasoline, but diesel requires an adequate loading of the engine in order to keep combustion temperature high enough to make use of it. Often, one can hear a slight miss in the engine due to fuel buildup. When the engine is first placed under a load after long periods of idling and wetstacking, it may blow some black exhaust out as it burns that excess fuel off. Continuous black exhaust from the stack when under a constant load is also an indication that all the fuel is not being burned.
.................................
Over the years I've heard truckers talking about it, but never dove in for the explanation. I just figured incomplete combustion, but thought it was an injector problem. Not engine loading.
Chris.
Title: Re: Generator suggestions
Post by: Dave Guilford on July 02, 2019, 11:32:33 pm
So it seems like getting all 6000w out of this will require something like this:

https://atielectrical.com/product/6503gu-cep-spider-box-input-30a-125250v/?gclid=Cj0KCQjwgezoBRDNARIsAGzEfe73kmUBZXI_JifHi2qThB_YhMEptjKylzS54uAwxQiwAq2H_ca2R8AaApVxEALw_wcB

BUT it would be broken out to 3 or more circuits, because this is only 40a (2x 20a). 

Yes?

Because 3 would allow up to 60amps, but of course our bottleneck is the 6000w produced.

Please let me know if Iím missing something.
Title: Re: Generator suggestions
Post by: Scott Holtzman on July 02, 2019, 11:33:39 pm
I suspect the "bad information" is a result of "Garbage In Garbge Out".  You asked for "50 amps at 120 volts".  That means different things to different people and in different contexts.  As Tim M said, you can get the 6000 watts out of the genny-but you can't run a 6000 watt/120 volt heater out of the genny.  Tim Hite pointed out you can get 30 amps at 240 volts-which also means you can get two times 30 amps at 120 volts. 30 +30 = 60, which is greater than 50.  If you don't need a 50 amp circuit anywhere.  Iy you have a single 120 volt load that requires more than 30 amps, then you are out of luck.

A sound system is not a single, steady load-it is a system of multiple, dynamic loads.  It's not hard-but it does take some effort to get "the maximum" out of a system.

I have to admit I made the assumption the max load at 120v would be 20amps per load and easy to distribute across the two legs.  A single 120v 60 amp device did not cross my mind.

I also figured that if the device needed that much current you would use the 240v option since you can have a mixed bag in the distro of 240 and 120. 

Title: Re: Generator suggestions
Post by: Russell Ault on July 03, 2019, 12:59:40 am
So it seems like getting all 6000w out of this will require something like this:

https://atielectrical.com/product/6503gu-cep-spider-box-input-30a-125250v/?gclid=Cj0KCQjwgezoBRDNARIsAGzEfe73kmUBZXI_JifHi2qThB_YhMEptjKylzS54uAwxQiwAq2H_ca2R8AaApVxEALw_wcB

BUT it would be broken out to 3 or more circuits, because this is only 40a (2x 20a). 

Yes?

Because 3 would allow up to 60amps, but of course our bottleneck is the 6000w produced.

Please let me know if Iím missing something.

Close. You'd need one with at least 4 circuits. You can only pull up to 30 amps off of each leg, so you'll need at least two circuits on each leg to get the maximum power out of the generator. Remember, a split-phase generator is not a single 60 A 120 V source, but really two separate 30 A 120 V sources. Same total power, but it needs to be balanced properly between the legs.

-Russ

-Russ
Title: Re: Generator suggestions
Post by: Dave Guilford on July 03, 2019, 08:43:20 am
Ok rad.  How do I run my macrotech I-series at 240v?   Do I get any benefit out of that?  My rack as follows:

1x ma9000i
1x ma12000i
1x Furman p1800ar
1x behringer Inuke 46000
1x Midas DL32 / m32

I think all/most could run at 240, but this rig gets used most of the time off power at venue.  Generator happens maybe 12x/year.  I want to keep this EASY and not move things in and out of 240/120.

So I THINK I want to keep 120 across the board.

Bonus points for anyone who can link me to a distro type unit thatíll do what I need , for under $400-500.
Title: Re: Generator suggestions
Post by: Rob Spence on July 03, 2019, 09:33:16 am
And, a racpak district will replace the Furman.
Title: Re: Generator suggestions
Post by: Mark Cadwallader on July 03, 2019, 10:30:40 am
In my area, I can easily (and cheaply) rent a 50A 120/240v "spider box" at a rental business.  If you have that available as an option in your area, your could make a special cable that has a L14-30 male plug and a California 50A female connector on the other end. The L14-30 would plug in to your generator, and the other end into the rented spider box.  That is a legal usage (30A plug in, 59A connector out). By analogy, you can pour a full 3 gallon bucket into a 5 gallon bucket, but not the other way around.

The adapter cord (with a rented spider box) is your cheapest option (at least in the short to medium term).
Title: Re: Generator suggestions
Post by: Tim Hite on July 03, 2019, 05:18:13 pm
Chris Hindle's response give the gist of what wet stacking is. Essentially, you will foul a diesel engine by running it below minimum operating temp. It's detrimental to performance and longevity. Preventing wet stacking in a prime power situation requires some planning and maybe a load bank to help get the motor up to temperature. I'm far from being an expert on the subject.

As an example, when I was working overseas, our operation was on diesel prime power. Maintenance had issues with users turning off all the lights and HVAC to "save on electricity" but turning everything off would drop the load enough to wet stack the 1.5MW gensets in use. The solution was to leave everything running 24/7, including office lights and HVAC. Sounds insane but kept everything running smoothly once the solution was implemented.



Hey Tim H, what is ďwet stackingĒ?
I am not familiar with that term.
Title: Re: Generator suggestions
Post by: Steve Crump on July 03, 2019, 07:57:08 pm
Ok rad.  How do I run my macrotech I-series at 240v?   Do I get any benefit out of that?  My rack as follows:

1x ma9000i
1x ma12000i
1x Furman p1800ar
1x behringer Inuke 46000
1x Midas DL32 / m32

I think all/most could run at 240, but this rig gets used most of the time off power at venue.  Generator happens maybe 12x/year.  I want to keep this EASY and not move things in and out of 240/120.

So I THINK I want to keep 120 across the board.

Bonus points for anyone who can link me to a distro type unit thatíll do what I need , for under $400-500.

https://www.amazon.com/Southwire-019703R02-Straight-Portable-Distributor/dp/B000289AQK/ref=asc_df_B000289AQK/?tag=hyprod-20&linkCode=df0&hvadid=167142956132&hvpos=1o2&hvnetw=g&hvrand=9721558687230259197&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9011091&hvtargid=pla-310690703240&psc=1


These arenít rack mount, but definitely fit the budget. Search for temp power distribution boxes. May not be ideal....thatís for you to decide. Northern Tool also carries some products for this use.

I use the LEX rack mount with a 50A plug inlet and 6 20AMP branch circuits, put half the load on A side and the other half on B side of the buss.





Title: Re: Generator suggestions
Post by: Steve Crump on July 03, 2019, 08:14:35 pm
Guys - next step- suggest to me a basic sister solution. I need a California style 50a/240v inlet broken down to 4x 15a 120v circuits.

Racked or standalone box.

https://www.northerntool.com/shop/tools/product_200434713_200434713