ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 3 4 [5] 6 7   Go Down

Author Topic: Generator suggestions  (Read 14935 times)

Tim Hite

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1221
    • Bad Quail
Re: Generator suggestions
« Reply #40 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.
Logged
Bad Quail
Sound + Light + Image
Joshua Tree, California
Authorized Dealer for all this stuff

Dave Guilford

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 402
Re: Generator suggestions
« Reply #41 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.

I’ll have to get a distro and some of that 50a California feeder.  Ug. 
Logged

Scott Holtzman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 7530
  • Ghost AV - Avon Lake, OH
    • Ghost Audio Visual Systems, LLC
Re: Generator suggestions
« Reply #42 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.

I’ll have to get a distro and some of that 50a California feeder.  Ug.

Great choice.  Give us a full report please.
Logged
Scott AKA "Skyking" Holtzman

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

Frank Koenig

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1318
  • Palo Alto, CA USA
Re: Generator suggestions
« Reply #43 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
Logged
"Nature abhors a vacuum tube." -- John Pierce, Bell Labs

Dave Guilford

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 402
Re: Generator suggestions
« Reply #44 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
Logged

Frank Koenig

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1318
  • Palo Alto, CA USA
Re: Generator suggestions
« Reply #45 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
Logged
"Nature abhors a vacuum tube." -- John Pierce, Bell Labs

Tim Hite

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1221
    • Bad Quail
Re: Generator suggestions
« Reply #46 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. . .
Logged
Bad Quail
Sound + Light + Image
Joshua Tree, California
Authorized Dealer for all this stuff

Dave Guilford

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 402
Re: Generator suggestions
« Reply #47 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, wouldn’t the 25a 240 California connectors deliver 50a at 120?

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

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 23741
  • Wichita, Kansas USA
Re: Generator suggestions
« Reply #48 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, wouldn’t 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.  That’s 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.
Logged
"If you're passing on your way, from Palm Springs to L.A., Give a wave to good ol' Dave, Say hello to progress and goodbye to the Moonlight Motor Inn." - Steve Spurgin, Moonlight Motor Inn

Tim Hite

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1221
    • Bad Quail
Re: Generator suggestions
« Reply #49 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, wouldn’t the 25a 240 California connectors deliver 50a at 120?

This generator specifies that it can make 50a at 120v.  That’s what I need - how do I pull all avail power with this genny?
Logged
Bad Quail
Sound + Light + Image
Joshua Tree, California
Authorized Dealer for all this stuff

ProSoundWeb Community

Re: Generator suggestions
« Reply #49 on: July 01, 2019, 11:58:19 AM »


Pages: 1 ... 3 4 [5] 6 7   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.05 seconds with 25 queries.