Data/Server Rack Installation Requirements

In no particular order:

1) It doesn't matter a **** how competent you think you are, or how competent you really are, or how much care you take to get it right, you are not DIYing in your own house and it is very likely that there are insurance and liability issues which mean that you cannot do this work yourself, and I guarantee you that there are laws which mean that you cannot do this work yourself.

2) By all means learn - we love you to learn, but right now there is such a gulf between your basic understanding of some vital and fundamental things, and what you need to know, that you cannot do this work yourself.

3) You can't terminate SWA into an IEC 60309 plug.

4) The higher current ratings for SWA assume XLPE insulation and cores running at 90°, which is not much use if you are taking it to accessories only rated to 70°.

5) I may myself be wrong here, but I don't think that 32A and 63A final circuits in data centres are wired as rings.

6) Server specs typically quote the maximum power that they will consume because the manufacturers don't know how many CPUs you'll put in, or at what clock speed, or how much memory, or how many disks ot how many PCI adapters. You might be able to get tailored power consumption data for large servers, where you're up into 10's of kVA, but for typical 1/2/4/8U servers of a few kVA they won't bother, and will just quote you the rating of the PSUs.

7) For the environment this is in you are way out of your depth and nowhere near competent to be doing it. This is real life, not a training exercise - you need to get an electrician in.
 
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I'd go with radial circuits for each and every cabinet, then if something pops the whole room won't fail.

Since some servers are likely to be hot swap or back up items, then (again) having everything on one circuit is dummy stuff.

You have made no mention of UPS or power backup, this tends to be mandatory and could again be done as 19" UPS boxes inside each cabinet or as a centralise mega UPS box.

Then there's UPS design and spec to consider, some UPS boxes feed the cabinet constantly and are thus in line, others simply having trickle charging so that in a power swap requirement (from mains to UPS) they are healthy, conditioned and able to support the load for the design (time) duration.

Resilience then adds to the issues, should the power for each server cabinet come from the same source, has the building design allowed for power supplies from different sub boxes.

I would suggest that you arrange to attend the potential clients project plan meetings and understand the requirements for the power works before any further thought is given to the matter.
 
softus said:
You really don't know? You were going to install a protective device that wouldn't have tripped on overcurrent until at least 40 Amps, supplying some appliances that would normally run at a combined total of about 12 Amps, and you can't see a problem with your approach?

and my 32A ring main feeding nothing at night except my 0.5A alarm clock?

BAS said:
4) The higher current ratings for SWA assume XLPE insulation and cores running at 90°, which is not much use if you are taking it to accessories only rated to 70°.

the figures I quoted were from table 4D4A.. 70C multicore armour..
 
ColJack said:
and my 32A ring main feeding nothing at night except my 0.5A alarm clock?
OK - so why don't you go ahead and use 16mm² cable for that RFC and protect it with a 60A breaker? :idea:
 
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the wonderful and unique UK Fused Plug copes with that dilemma.

Wouldn't work with industrial plugs though

BTW a UPS inside each cabinet is much better. Otherwise the night shift might unplug a cabinet to boil their kettle. Or possibly someone will trip over a cable and pul the plug out.
 
the 1000w PSUs probably state 10A as no doubt they will be universal input active PFC type SMPS which can run from around 70-260V, and at 110v for use in the usa theyll probably draw around 9-10A at full load
 
the 1000w PSUs probably state 10A as no doubt they will be universal input active PFC type SMPS which can run from around 70-260V, and at 110v for use in the usa theyll probably draw around 9-10A at full load
That issue had been dealt with, and I'm inclined to think that you're wrong about it.
 
the 1000w PSUs probably state 10A as no doubt they will be universal input active PFC type SMPS which can run from around 70-260V, and at 110v for use in the usa theyll probably draw around 9-10A at full load

I have actually contacted the manufacturer of the PSU on this matter, and they state that at full load, it does use up to 10Amp @ 250V which is why its written on there...@125V it uses up to 15 Amp
 
RB2004 said:
I have actually contacted the manufacturer of the PSU on this matter, and they state that at full load, it does use up to 10Amp @ 250V which is why its written on there...@125V it uses up to 15 Amp
So, based on that information, what proportion of the time will they be running at "full load", and how do you intend to apply diversity in the circuit design?
 
That's one hell of an inefficient PSU if it draws 2.5kW to supply 1kW on the outputs. A fan and heatsink arrangement won't get rid of 1.5kW worth of heat!
 
depends what the power factor is like, remember you can have current flow without any net transfer of power.

but I agree it does sound rather high. Of course it could just be the manufacturer erring on the side of caution in thier specs.
 
wouldn't the highest load be when it is charging a depleted battery as well as running the server?
 
he said PSU not UPS but yes any decent UPS should be expected to draw far more than it's output rating while recharging after an outage.
 
I believe that John's subtle but super-valid point is that the PSU consumption is only part of the equation, because the maximum draw will be 10A [supposedly] for each PSU plus whatever draw is needed for each UPS during its recharge cycle.

It all goes to show that the OP is not even close to working out the design load, or being aware that he needs to.
 

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