Y Power Cord Between Servers

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bhsrnd

bhsrnd

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Does anyone see any potential issues with using a Y power cord (1 male to 2 female) to power two different servers? These servers have dual power supplies but only require one to function.

Basically, the idea is to use this cord to provide power from PDU#1 to one power supply on two different servers and then use a second cord to do the same thing with the other two power supplies but supplying power from PDU#2 for power redundancy. I would like to post a graphical representation but I am not allowed to according to my Posting Rules. Maybe a Moderator would be kind enough to help me out with that :)?

The rack power strips will be 208V 20A 3PH 5W (L21-20P) split into three 120V 20A banks of five outlets. Would there be ground-loop problems or other issues?

I'm not too fond of making a "bridged" connection like that. Two separate cords for each server accomplishing the same task is one thing, but a single shared cord is another to me.

Thoughts???
 
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This is a common way of wiring servers. Two different Y cables are plugged into two different circuits. To each of the four ends of the Y (2 pairs = 4 females ...) are attached extensions of whatever required length with the appropriate connectors (our servers use some weird looking connector I've never seen ANYWHERE else on the planet ...) Those ends are then fed so that each of the two redundant power supplies on each of the two (or more ...) servers is fed by a different circuit. In theory, if one of the circuits goes buh-bye the supply on the other circuit provides power.

If there's a problem, no one I know has run into it.
 
Sounds lilke, and it's a perfectly normal sort of thing. I've even seen an assembly that had a single plug and 5 or 6 IEC-type (aka "PC") connectors. They're quite handy for wiring racks of servers. (One rack might contain 35-40 individual servers. It's impossible to find dense enough plugmold or power strips.)
 
zbang said:
Sounds lilke, and it's a perfectly normal sort of thing. I've even seen an assembly that had a single plug and 5 or 6 IEC-type (aka "PC") connectors. They're quite handy for wiring racks of servers. (One rack might contain 35-40 individual servers. It's impossible to find dense enough plugmold or power strips.)
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Most REAL racks (as opposed to racks from Wally World, I suppose) have some form of integrated power supply / management system.

I DESPISE the multiple plug power cords like what you describe. If y'all ever have any way to influence the kind of racks being bought, don't let them buy racks that require power strips or any other kind of foolishness.
 
tallgirl said:
Most REAL racks (as opposed to racks from Wally World, I suppose) have some form of integrated power supply / management system.
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Just about all 4-post racks (cabinets, like Liebert or Rittel) have the option of power distro, but few include it in the base unit. and some clients won't pay for the rack mfg's parts. Likewise, 2-post telecom racks (usually chatsworth) never come with power distro parts.

tallgirl said:
I DESPISE the multiple plug power cords like what you describe. If y'all ever have any way to influence the kind of racks being bought, don't let them buy racks that require power strips or any other kind of foolishness.
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I don't think much of them either, but if it's a choice between a bunch of plastic power strips hanging in the back of the cabinet and some neat cable assemblies plugged into proper distro gear, I'll take the latter.
 
zbang said:
Just about all 4-post racks (cabinets, like Liebert or Rittel) have the option of power distro, but few include it in the base unit. and some clients won't pay for the rack mfg's parts. Likewise, 2-post telecom racks (usually chatsworth) never come with power distro parts.
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Yeah, those would be the ones I see on sale at Wally World ;)

Sorry -- I work for a company that manufactures servers and have been spoiled for a very long time now.

I don't think much of them either, but if it's a choice between a bunch of plastic power strips hanging in the back of the cabinet and some neat cable assemblies plugged into proper distro gear, I'll take the latter.
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If that's the choice, then I'll pick the electric squid over power strips as well.

Personally, I don't understand how anyone could put together a rack that's going to be as much of a mess as something with a zillion cords going into it, but I'm (a) a neat-freak when it comes to racks and (b) not paying for the equipment I work with, so I don't care :D
 
Just from a reliability/serviceability standpoint I would greatly prefer individual cords from each input of each piece to it's own outlet- the idea of losing a whole string of power when one cord gets pulled or goes bad would bother me. Fewer single points of failure with multiple cords. I realize that this means more outlets, but I think it's more reliable.

When ya start geting past 3 or 4 9's of reliability for a goal, ease and simplicity of maintenance have to be factored in.
 
If you've got a problem with cords being pulled out, you've got a bigger problem than one which can be solved by having individual cords for each device.

My experience is that some form of rack-mounted power distribution device, even if it's just a rack-mounted power strip, is the most trouble-free solution going. Amongst other things, it greatly reduces the number of cords on the floor. If your racks are arranged back-to-back with the cables lying in an alley between the backs, that's a huge win since it reduces alleyway clutter. If your machines aren't arranged back-to-back the advantage isn't as great, but it does reduce the number of wires you can trip on. Dittos for rack mounting switches, KVMs and just about everything else.
 
tallgirl said:
My experience is that some form of rack-mounted power distribution device, even if it's just a rack-mounted power strip, is the most trouble-free solution going. Amongst other things, it greatly reduces the number of cords on the floor.
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Agreed. I just don't like the "daisy chained" cords
 
RayS said:
Agreed. I just don't like the "daisy chained" cords
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Neither do I. I think they are flakey as can be. Unfortunately I have no choice with one model of server I have at work -- the connector on the power supply is non-standard and the only cable which connects to it has a male "PC" connector on the other end.

The other configuration that creates problems is when the cords on a multiple conductor cord aren't long enough and then they have to be daisy chained. That's not a problem with a rack full of 1U servers that are all the same model, but fill a rack with different models, or heights greater than 1 or 2U, and those cords just don't work so good.
 
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