large power supplies

[Ulan]

I could use some help clarifying some things.

I understand the basics of the power injection as explained in this nice write up.  http://spikerlights.com/pwrinjection.aspx    With multiple power supplies don't let the power get back to the board.

My question comes around scaling up the power supplies and ones that can be ran in parallel.   Lets say I want to run a lot of lights like a couple mega trees and/or some large matrix or nets.   Lots and lots of lights in a particular area.   

Can I get a couple power supplies like (https://www.trcelectronics.com/View/Mean-Well/HRPG-1000-12.shtml) that has a parallel feature, 1000 watt, 12 volt, 80amps, wire them together and run a 10 gauge (is that right 30amp wire?) wire to a bunch of distro boards?  The distro boards say 30amp input but the large power supplies all have much higher amps and I'm not sure if that would be ok or a terrible thing. If it wont work, could i use some sort of step down board/thingie?   I see videos of people using large supplies but I can't find the details explained at my level on how to make it work safely.   

Any pointers are welcome.

Thanks

[Emuney18]

My understanding is that yes that will work for what you describe.  I hope someone else will confirm that is more qualified to answer you. I would fuse that wire going to the distro board in case something happens because your 10 awg wire would not handle 80 amps.  Assume you have it all hooked up.  The power supply will only output what is asked of it so that if no distro ever needs more than 30 to drive its lights then it will be fine.  If you power 1 light then very little amperage will go to the wire and the power supply will output very little.  If you power 1000 lights then the power supply will output that amperage.


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[AAH]

Pretty well all of the 100W plus power supplies have multiple V+ and V- terminals which are physically connected directly in parallel. Power supplies that can be wired in parallel are a different thing. They are power supplies that are typically used for redundant backups in servers and similar. They are the few type of power supplies where you can connect the V- and V+ both at the same time whereas for Chrissy lighting it's typically just the V- that is connected between power supplies and all the V+ of different power supplies are connected separately. The reason that most power supplies have multiple V- and V+ terminals is that the terminals themselves are rated to a maximum of 30 Amps. So if you have a 400W 80A 5V power supply you need 3 outputs to be able to distribute the current.

[Ulan]

My understanding is that yes that will work for what you describe.  I hope someone else will confirm that is more qualified to answer you. I would fuse that wire going to the distro board in case something happens because your 10 awg wire would not handle 80 amps.  Assume you have it all hooked up.  The power supply will only output what is asked of it so that if no distro ever needs more than 30 to drive its lights then it will be fine.  If you power 1 light then very little amperage will go to the wire and the power supply will output very little.  If you power 1000 lights then the power supply will output that amperage.


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If i have 2000 lights powered across multiple boards, would it be ok and each board get what is drawing (30amps or less) or would each board get the high amps of the total required across all the boards?

[Ulan]

Pretty well all of the 100W plus power supplies have multiple V+ and V- terminals which are physically connected directly in parallel. Power supplies that can be wired in parallel are a different thing. They are power supplies that are typically used for redundant backups in servers and similar. They are the few type of power supplies where you can connect the V- and V+ both at the same time whereas for Chrissy lighting it's typically just the V- that is connected between power supplies and all the V+ of different power supplies are connected separately. The reason that most power supplies have multiple V- and V+ terminals is that the terminals themselves are rated to a maximum of 30 Amps. So if you have a 400W 80A 5V power supply you need 3 outputs to be able to distribute the current.

The power supplies that have parallel feature that I am looking at explicitly say "Current sharing operate in parallel up to 4 units: 4000W or 3+1 redundancy" which sounds to me that they stack the 1000 watt supplies to 4000 and would power more lights but could be very wrong.  The wire diagram in the tech spec shows all the + and - and ground wired together on the supplies.  I don't understand if the high amps should cause concern.   Thanks!

[jnealand]

Since this is primarily a consumer oriented hobby why would you try to step up into using high power commercial grade power supplies?  Why not just split things up and stay safe and in a knowledge area where there is lots of experienced help.  I for one have no desire to get involved with things that are not common and do not have plenty of experienced help available.  Just my 2 cents

[k6ccc]

From reading the description of the linked power supply, you could parallel up to four of them.  However, my question would be: for what purpose?  There is essentially nothing to be gained by using a single very large power source vs several smaller ones.  One major disadvantage is that it is if you keep the power supply (or supplies) close to the props, there is less voltage drop in wiring.  That means that your voltages stay far more constant.  From a power loss standpoint, it is much easier to distribute 120V AC than 12V DC.  Also a failed power supply takes out a much larger portion of your show.  I am following my own advise.  For my pixel tree, I have four 350 watt power supplies in a 12 x 12 x 6 PVC electrical box - each of which power one half of a SanDevices E682 controller.  If I were to want to use a single large supply, this would be the ideal candidate since all four power supplies are right next to each other.
There is also a safety concern.  As someone else suggested, you absolutely should fuse the distribution from the large power supply to each distribution board.  However it becomes very important to work safely around high current power sources - no rings, watches, necklaces, loose keys, etc; and working with properly insulated tools.  Take this very seriously: short circuit 12 volts at a couple hundred amps across your metal wristwatch will likely result in an amputation mid lower arm.
BTW, at work, I deal with 48 volts at hundreds of amps (short circuit capability in the tens of thousands of amps) on a somewhat regular basis.  I have seen the result of a 1/4 inch stainless steel bolt that was turned into plasma faster than you could blink.  The guy who was next to it was off work for three weeks and got to know the Docs at the Grossman Burn Center better than most of us would like.  When dealing with the high current stuff, we NEVER work alone and always have a person who is only there to watch for safety issues.

[Emuney18]

I knew someone smarter than me would speak up. I had not thought about the human danger of higher amperage.  I know my own electrical ignorance and I don't mess with it.  From a financial standpoint this doesn't make sense either because for the same $200 you can get 6 of the 350watt mean wells and get twice the power.


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[aknflyer]

The reason that most power supplies have multiple V- and V+ terminals is that the terminals themselves are rated to a maximum of 30 Amps. So if you have a 400W 80A 5V power supply you need 3 outputs to be able to distribute the current.

This is a very good point, often overlooked. +1 for AAH!

[Ulan]

Just to close the loop on this, yes electricity is dangerous. 

I'll see if the terminals are 30 amps each, that would be ideal.  Otherwise the high current may cause fuzzes to break.  Because of math/ohms laws, you can't adjust current without adjusting volts, so plan B looks like a 24 volt supplies and step them down to 12v/30amps where required.

Thanks!

[aknflyer]

Just to close the loop on this, yes electricity is dangerous. 

I'll see if the terminals are 30 amps each, that would be ideal.  Otherwise the high current may cause fuzzes to break.  Because of math/ohms laws, you can't adjust current without adjusting volts, so plan B looks like a 24 volt supplies and step them down to 12v/30amps where required.

Thanks!

40 yr telecom/electronics tech here, while I have no experience with powersupplys that you can bridge. I can speak to your use of distro boards.
If the board is rated for 30a, then unless your strings are drawing that many amps, then your ok. Think of a hose, if the sprayer is choked down, but the utility supplies 800 gallons/min, but your only using 2 gallons/minute, then the flow is only 2 gallons/minute. So your draw on the circuit is limited to the max your strings, floods, ect are actually drawing. Even if you have a 10000 amp supply this still applies.

[tooms]

The bigger problem is having that many pixels within 5 metres of your 1000 amp DC 12v power supply.

[Ulan]

The bigger problem is having that many pixels within 5 metres of your 1000 amp DC 12v power supply.

Any decent sized martix or mega tree would easily use 1000 watts within a short range.   That is only 1200-1500 lights.

[Ulan]

I think I found a fantastic alternative for a power supply with high wattage.   HP common slot server 1200 watt power supplies refurbished are dirt cheap.  They are cycled out of server farms with plenty of life left to run some pixels for a few weeks.  You just need a server power supply breakout board which gives you individual ports like a traditional supply.    =)