Wiring a rack based distro.

M

Mark Hunt

Freshman
Oct 26, 2012
8
0
0
Hi all, I've read posts here a lot and lots of great, knowledgeable people here. This is my first post.

This is my amp gear:
4 - XTI 4002 running in bridged mono to run 4 SRX728S's subs
4 - XTI 2002 running in bridge mono to run 4 SRX728 tops

Here is my confusion. The XTI's are 20A devices so if I wire 4 in one rack to a L14-30 or CS-6965 isn't that an amp mismatch?

4 x 20A = 80A so I would need an 80A circuit, at the minimum, to run the 4 amplifiers and not a 30A or 50A circuit?

What type plug will I run into the most in gyms and small clubs? I'm a Nuclear Engineer by education not an EE or electrician.

Are there pre-made rack systems I can buy I can just plug my XTI's into a rack distro and just plug the distro input into the venue outlets?

Are there any places online where I can get schematics for building/wiring my own distro?

Thanks for all the help.
 
XTi's (with the exception of the 6002) will run on a 15 amp circuit. I would just get a commercially available rac pak (motion labs, theatrixx, etc). I don't have access to the data sheets, but I would be willing to bet you don't need anywhere near 80A per rack.


Sent from my iPhone
 
Re: Wiring a rack based distro.

Mark,

It is pretty standard to have 20a outlets and breakers on your distro fed by a 30a plug, so each circuit could only pull 15a before tripping the upstream breaker. Except in edge cases, amplifiers are unlikely to be looking for maximum current draw.

You should just buy a pre-built solution from Motion Labs or Six2.
 
Re: Wiring a rack based distro.

I've been doing more research and understand now all the camlock splits and DPU circuits are all parallel. So that when you hook up to a 100A or 200A or more dedicated service plug then all circuits see the 100A so for 4 amps on a 100A circuit won't come close to tripping. However if you run into a situation at a club all you have is the L5-30 (std edison) from a wall you can't distribute that because it most likely is a 15-20A circuit and if you distribute that across 4 parallel circuits you will blow the 20A at the wall circuit in the breaker box.

One last question. Would you make a rack that had multiple distribution systems for a mobile gig? Like 6, 50A circuits fed with camlocks and also 6, 30A circuits fed L14-30 and another set-up with with a third option. Or is just advancing the gig and seeing what that have and make the required changes before I get there?

Again thanks for the help/info.
 
Re: Wiring a rack based distro.

Hi Mark-

So that when you hook up to a 100A or 200A or more dedicated service plug then all circuits see the 100A so for 4 amps on a 100A circuit won't come close to tripping.
Click to expand...

Eh, sort of. Directly connected to the hot bus bars in a distro (or your home breaker box) are the over-current protection devices (Code-speak for fuse or circuit breaker), and the smaller wire that runs to an outlet connects to that device. They don't "see" anything... but if you draw more than 80% of rated trip current for an extended period, they will trip. If you have multiples of such circuits connected to a 100 amp service, it is possible that you will trip its breaker/blow fuses.

However if you run into a situation at a club all you have is the L5-30 (std edison) from a wall you can't distribute that because it most likely is a 15-20A circuit and if you distribute that across 4 parallel circuits you will blow the 20A at the wall circuit in the breaker box.
Click to expand...

You're screwed if you really need to power a rig that draws that much current in a venue that small/unprepared/clueless.

Would you make a rack that had multiple distribution systems for a mobile gig?
Click to expand...

It's to your benefit to package your gear so that it deploys quickly in the ways you most often use it. If you're working mostly in venues with wall outlets for power, you really can skip buying "real" power distribution for the moment. If you have clients/venues that you want to keep servicing in spite of their electrical service, you'll need to figure out how to accommodate it should you move into your own distribution for your other gigs. Advancing with a phone call or 2 is good, and a personal visit is even better...

How much power do you need? How many amp racks, with how many of what amplifiers? How hard do you run your rig(s)?
 
Re: Wiring a rack based distro.

How much power do you need? How many amp racks, with how many of what amplifiers? How hard do you run your rig(s)?
Click to expand...

This is my amp gear for now:
4 - XTI 4002 running in bridged mono to run 4 SRX728S's subs
4 - XTI 2002 running in bridge mono to run 4 SRX728 tops
 
Re: Wiring a rack based distro.

Mark Hunt said:
This is my amp gear for now:
4 - XTI 4002 running in bridged mono to run 4 SRX728S's subs
4 - XTI 2002 running in bridge mono to run 4 SRX728 tops
Click to expand...

Mark you realize that at 3,200 watts per amplifier that the power greatly exceeds what a single 20A 120 V circuit can supply? It sort of defeats the whole purpose of the 2:1 power rule-of-thumb thing.

I guess if you want this configuration you might as well plug them all in to 220 V outlets.

I am going to guess this it a DJ rig based on lack of stage monitors which means higher duty cycle (more sustained energy to the load) then a live rig.
 
Re: Wiring a rack based distro.

Tim Perry said:
Mark you realize that at 3,200 watts per amplifier that the power greatly exceeds what a single 20A 120 V circuit can supply? It sort of defeats the whole purpose of the 2:1 power rule-of-thumb thing.

I guess if you want this configuration you might as well plug them all in to 220 V outlets.

I am going to guess this it a DJ rig based on lack of stage monitors which means higher duty cycle (more sustained energy to the load) then a live rig.
Click to expand...

Guys all over the world (myself included) are running 4000's and 4002's off of 15A without a problem. I still say get a pair of racks pacs, fed by whatever type of tie-in is common in your area. Perhaps you could tell us where you are located and some local guys might be able to advise.
 
Spenser Hamilton said:
Guys all over the world (myself included) are running 4000's and 4002's off of 15A without a problem. I still say get a pair of racks pacs, fed by whatever type of tie-in is common in your area. Perhaps you could tell us where you are located and some local guys might be able to advise.
Click to expand...

+1. 1/8 rated power draw from the wall if you're tapping clip/limit on the inputs of the amp is a pretty safe bet for most musical content. Your mileage may vary with dubstep, in the subwoofer passband.
 
Re: Wiring a rack based distro.

Mark you realize that at 3,200 watts per amplifier that the power greatly exceeds what a single 20A 120 V circuit can supply? It sort of defeats the whole purpose of the 2:1 power rule-of-thumb thing.

I guess if you want this configuration you might as well plug them all in to 220 V outlets.

I am going to guess this it a DJ rig based on lack of stage monitors which means higher duty cycle (more sustained energy to the load) then a live rig.[\QUOTE]

No I didn't list everything. It is a live band rig for my band. Also I've read at full power 1/8 pink the 4002 only draws 15A. Is that wrong?
Click to expand...
 
Re: Wiring a rack based distro.

Mark Hunt said:
No I didn't list everything. It is a live band rig for my band. Also I've read at full power 1/8 pink the 4002 only draws 15A. Is that wrong?
Click to expand...

[\quote]

Mark, I tend to look at things in a 'worst case' situation. For live music I can generate a whole lot of sound on a very few circuits.

In an effort to provide some practical answers for you I offer the following:

In my neck of the woods A 50A 4 wire 240V drier plug is becoming common in the larger clubs. Most bands and sound companies use do it yourself type distros rather then the more expensive certified versions. I recommend your attention to the Peavey Power distro. It's 6 circuits, only a few hundred $ and you don't have to build it.
 
Re: Wiring a rack based distro.

Sounds like a fun rig. Are there multiple racks? How many of each type amp in each rack? I have both the aforementioned Motionlab and Six2 small distro rackpac and they are both helpful but unfortunately rarely used due to the typical small venues we deal with. The distro thingys are just the tip of the iceburg 'cause after that it's 6/4 SO and hauling and storage and then it's stringers and other stuff that weigh a lot and cost even more. I have a few hefty 10/3 SO standard quad box A/C cables in various lengths for places that don't have a range plug or cams - I'm not the type to go digging around in a main breaker box with bare wires. As mentioned before - you can make a lot of noise with just 1 or 2 circuits.
 
Re: Wiring a rack based distro.

As a solution for the small venues where one needs to connect to more than one circuit, I keep a few of these custom 1 rack space distros in stock...

1RUfront-nologo.jpg


1RUback-crop.jpg


They are fed by two 32a powercon inputs, have isolated neutrals and star grounding. Each input feeds a pair of 20a breakers. Each breaker powers a pair of 20a edisons on the back. The internal wiring between the powercons and breakers is 10 gauge, so they can be plugged in to two separate outlets up to 30 amp or into a custom split adapter if there is something like a L14-30R available.

This setup lets you keep all you amps and other rack gear plugged in to the distro, then adapt externally to the venue power.
 
Top Bottom