Power questions

[Faux127]

Hey guys, I searched a bunch and found some good info, but not exactly what I was looking for, or couldn't apply it to my own situation.

I'm concerned about tripping breakers and/or undersupplying my equipment. I'm new to electricity, so I'm trying to understand all this stuff.

My rack (in the near future) consists of:
Furman M8x2
Driverack PA+
Peavey ipr2 2k for 4 Otop 12's (deltalite II 2512)
Peavey ipr2 3k for 4 T48s (kappalite 3015lf)

Here's my math:

Titan 50v @ 10ohms = 250w & 5A
x4

Otop12 250w rms @ 8ohms = 5.6A (I didn't see limiting voltages in my plans, so I just used RMS values from spec sheet)
x4

ipr2 3000 load:
channel A: 50v @ 5ohm = 500w & 10A
channel B: 50v @ 5ohm = 500w & 10A

ipr2 2000 load:
channel A: 500w @ 4ohm = 11.2A
channel B: 500w @ 4ohm = 11.2A

Does this look correct?
I know that I'm not playing pure sine waves, so I have wiggle room because these are all RMS ratings.
If this is correct, then how many 15A circuits do I need to supply this power? Do I just sum the currents and split it up on different circuits?
Basically, what should I do about getting adequate power? (lowest budget possible please )


Bonus question:
I thought you were supposed to plug amps into a power conditioner so that when you have unreliable power (I will be running this rig 99% of the time off a generator outdoors) you don't damage your equipment with brown-outs. I read Bill had said in another topic that you want to plug your amps directly into the power source?

[Grant Bunter]

I struggled with this when buying a generator.
I have run up to 4 x t39's, 2 x DR250's, 2 x WH8's + rack/mixer/amps and 4 x par 56's (but not at 100%) with a 7KvA generator and it didn't sag whatsoever. My T39 amp is a little more modest power consumption wise as my voltage limit is 35V.

My own feelings on the Furman or other conditioners is that they are only able to provide constant power for a limited time if the source isn't providing enough to top it up, and provided the supply is within 5% of rated power. A brown out is typically more than 5%.

So look at a quality generator that self adjusts revs based on load.
Going from a "regular" 7KvA genny to one with a large a fuel tank as possible (mine lets me run 20 hours straight per tank) doubled the cost.

So, without going through the math, I recommend at least a 7KvA genny.
You need to look at maximum power consumtion at full load to calculate power requirement per amp, which should be available in the user guide, and after that some "headroom" for want of putting it any other way...

[sine143]

My issue with the furman and other conditioners is that they basically give you 8 outlets on a single 15 amp breaker, which is severlynlimiting. amps have power conditioners inside them.

Ive tripped plenty a 15 amp breaker with 6 t48s. ive yet to trip a 20 amp breaker with this number of cabs (although the internal fuse in mu xti 4002 has tripped).

If you need multiple circuits, what you should look for is a 'distro' not a conditioner. motion labs has many nice options. even peavey has a decent one. im currently using a regular home sub panel fed by 20 feet of 4awg, terminating in 50 amp hubbel connectore (and i have adapters for other situations. ive split this into 2x 20 amp 120, 20x 30 amp 120 and 2x15 amp 120 all individually breakered.


These guys have some affordable options, though without the cerification of say the motion labs or peavey unit


http://www.ampshop.com/distro.html

Basically, if you can access a single 20 amp, and a single 15 amp, and feed it with the thickest, shortest power cord yiu can afford, you will be fine in all situations. for sketchy venues find the outlets closest to the breaker and run thick drop cord (Some venues/bars etc have shoddy in wall wiring, causing voltage drop from hell, which our digi amps hateeee))

[Faux127]

I'm thinking of just going overkill with the genny, that way I can run everything I want without worrying.

http://www.homedepot.com/p/Smarter-Tool ... escription

94 reviews with an overall 5 star rating


If I were to have that, then I could just run three extension cables, one for each amp, and one for the furman which powers my PA+ and all the power strips for DJ gear.
Each of those sockets is on it's own 20A circuit, right?

I would love to expand with a distro and all that, but I don't have any desire to go bigger than the 8 cabs I'll have, and I'm hoping to get by with the equipment I have available to me.

[sine143]

that generator has 2 30 map (1 is 240v) and 2 20 amp breakers.


Now.... that type of generator (construction type generator) can be damaging to sensitive electronics (laptops, maybe even power amps). It may be worth it to look into a "inverter" type generator as these provide cleaner power.


sorry, I did not know you were going generator, reader fail on my part.

[Faux127]

that generator has 2 30 map (1 is 240v) and 2 20 amp breakers.


Now.... that type of generator (construction type generator) can be damaging to sensitive electronics (laptops, maybe even power amps). It may be worth it to look into a "inverter" type generator as these provide cleaner power.


sorry, I did not know you were going generator, reader fail on my part.

There's no way in hell I could afford an inverter type genny...
http://www.homedepot.com/p/LIFAN-2-800- ... 9nZ1z0z72o

That's more than I would spend on the other one, and it's only 2800 watts. Is there any sort of conditioning I can do to the construction one? I've only ever seen people use construction ones for small outdoor parties..

[Bill Fitzmaurice]

There's no way in hell I could afford an inverter type genny...

You can by not wasting money on a power conditioner.

[byacey]

Most of the so called "power conditioners" are little more than a fancy power bar with some varistors to absorb over-voltage spikes. They don't do anything about low line conditions or elevated line voltage until it hits the zener point of the varistors, usually 140V or so.

[sine143]

i'm just saying.... I'd be leery of plugging in 2 cdj 2000s, and a djm 900 (about 6k in gear) into an 800 dollar generator.

[Faux127]

Hmmmmm.....

Well it's either the construction type, or no genny, and if no genny, then no point in building cabs
So I guess I'll have to live with the risk *shrug*

Plus, I doubt anyone will bring their nice tables to our private gatherings.

So I suppose I could run both amps off a 20A circuit, and everything else off the other 20A circuit. Seems like the best idea without spending hundreds more dollars.

[sine143]

I would rather have this, despite being half the power.

http://www.amazon.com/Champion-Power-Eq ... +generator

realistically, with only 4 t48s, I doubt you'll be giving the otop12s more than 100 watts a piece (and thats being generous). OTops SCREAM. The T48s will only be drawing about 1500 watts if you are full on bludgeoning them with sine waves. 3100 is likely more than enough.

[Faux127]

I would rather have this, despite being half the power.

http://www.amazon.com/Champion-Power-Eq ... +generator

realistically, with only 4 t48s, I doubt you'll be giving the otop12s more than 100 watts a piece (and thats being generous). OTops SCREAM. The T48s will only be drawing about 1500 watts if you are full on bludgeoning them with sine waves. 3100 is likely more than enough.

That's around my price range... Do you think 3100w is sufficient for the power I will need for the amps? 1kw rms for the subs, 1kw for the tops, leaving 1kw for electrical devices?

Reading that a UPS can help alleviate voltage drops resulting in damage, any input on that?

[Bill Fitzmaurice]

Reading that a UPS can help alleviate voltage drops resulting in damage, any input on that?

One capable of handling the current draw of power amps will cost as much as that generator.

[Faux127]

Reading that a UPS can help alleviate voltage drops resulting in damage, any input on that?

One capable of handling the current draw of power amps will cost as much as that generator.

I didn't even think of that *doh*

So the inverter genny that sine143 posted looks nice, do you think it'll have the juice to power my rig?



edit:
Others are saying that a genny that produces a fair amount of headroom relative to what you're powering, along with Automatic Voltage Regulation should give clean power.

like this:
http://www.costco.com/Westinghouse-7000 ... 54388.html

Thoughts?



edit again:
clean power in a sense of the same effect as using a UPS between the genny and everything else, and headroom so the engine never bogs down.

[David Raehn]

A venue that I set up at a few times a year has three of the 3k inverter gennys. Unfortunately, once I used them the first time, I began to covet..... To me, they are THAT good. For the time being, they will remain low on the wish list due to their price.