Newbie

[Bossman]

Hello everybody,
I am not a refrigeration engineer but a network systems manager and i am looking for advise on air con for our server room which at the moment is at a warm 32 deg C
constant which is no good for the servers as they need a constant temp of between 18 - 22 deg C to ensure they do not overheat.I have the thermal cututs on the cpu's set to shutdown the servers when the core temp gets to 70 deg C so as not to damage them. The room itself is 3.3M square but has 8 server units plus switching gear.
I have estimated that the output for each server is approx 500watts and i estimate we would need at least a 18000 BTU split unit to give us the required cooling element. We have been given all types of prices but i would like to put it to this forum and get a realistic price for unit plus professional fitting. I would appreciate as I have been working under these conditions for the past 3 years and all SMT comes up with is a move to another part of the school which still leaves the poor servers in the heat. We are a very poor school underfunded but i would welcome anybodies recommendations.
regards
Adrian Staff aka Bossman

[frank]

I have estimated that the output for each server is approx 500watts and i estimate we would need at least a 18000 BTU split unit

Why swop between SI and Imperial?

If you have 8 servers @ 500w then you need 4kw + room loads.

It always amazes me why some people leave it till the last minute or until there is a problem before seeking a solution to the problem.

Reminds me of a recent episode in ambients of 28C where we were called out to a Board Meeting where all the top 'brains' were seated complaining that they were sweating because the AC wasn't working. So we dropped everything to race across town to attend (as it is one of our major customers) only to find that the controller was set to heating with a set point of 32C .

Anyone ever hear of planning?

Apologies if I seem in an unhelpful mood.

[kris]

your servers will perform far better when you get this sorted! get options from your companys differant spec units.

air conditioning is like anything' you get what you pay for'
Ask for high ,middle and low spec systems.

higher spec 10kw inverter+ fitting,guess about 5k

[frank]

higher spec 10kw inverter+ fitting,guess about 5k

within a 50 mile radius of Nottingham I'll fit a 10kW unit for around 4k including reasonable mains electrics

[slingblade]

within a 50 mile radius of Nottingham I'll fit a 10kW unit for around 4k including reasonable mains electrics

Ill do it for £3995, and i might work on a weekend.

CASH ONLY.

[Andy W]

Christ, I must be too cheap, that is why I am always busy.

[wambat]

You may want to look into spot coolers, They are fairly easy to install are reletively mobile and here across the pond they can be leased or bought.
TryThis: http://www.aggreko.com/AggrekoApps/S...heet.asp?id=43

[wambat]

Why swop between SI and Imperial?

If you have 8 servers @ 500w then you need 4kw + room loads.

It always amazes me why some people leave it till the last minute or until there is a problem before seeking a solution to the problem.

Reminds me of a recent episode in ambients of 28C where we were called out to a Board Meeting where all the top 'brains' were seated complaining that they were sweating because the AC wasn't working. So we dropped everything to race across town to attend (as it is one of our major customers) only to find that the controller was set to heating with a set point of 32C .

Anyone ever hear of planning?

Apologies if I seem in an unhelpful mood.

Frank, I,m concerned, your usually so mild mannerd
Tell the boss you and the Misses need a vacation, on him of course!

[Andy]

Ill do it for £3995, and i might work on a weekend.

CASH ONLY.

I'll do it for £4,005

there you go three quotes, one cheap one not so cheap and then the rolls

Kind Regards Andy

[Abe]

Ill do it for £3995, and i might work on a weekend.

CASH ONLY.

Yes, you might, but is yours LG ?

[Abe]

Frank, I,m concerned, your usually so mild mannerd
Tell the boss you and the Misses need a vacation, on him of course!

Frank is the BOSS

[frank]

Apologies all round - difficult day full of idiot customers wanting all sorts of stupid things yesterday.

Just because the SUN came out for a few hours in England .

Their lack of planning and tight fistedness (lack of willing to spend any money when the sun isn't out) suddenly becomes my problems .

On top of all that, when I got home I found that there was no cold cans of BEER in the fridge (Yes, I know, that's also lack of planning )

[Bossman]

Frank I empathise with you on that score. I totally agree with your attitude towards these f--k wits who call themselves senior management and have to call meetings to discuss the meetings they had ten days ago. Then when they decide what they are going to do they have another meeting to justify what they have decided. Sorry but i had planned everything down to the last bit (sorry for the pun) binary talk and the boss's brother instead of listening to me went ahead and cancelled the install of AC in the server room all cos the engineer said it would be a little difficult but not impossible to fit (wanted away from the job to go on holiday) So there we are 3 years later same problem. Boss's brother has since bin promoted from caretaker to site manager and a big fat pay rise to boot and me well i can now live for quite some time without dehydrating in the gobi desert after becoming imune to heat.

[slingblade]

Yes, you might, but is yours LG ?

Why? dont B&Q do a 10 KW ?

[bebad]

B&Q it! Don't do it

[The MG Pony]

You know what you need to do? Start shutting down random servers at very inconvenient times and tell them it is due to "heat" issues, that will get them on the ball right fast, Set the thermal shut downs to 60C, second load goes up they go down and that way you won't be lying when you say it was due to heat issues to boot

(Hehe It has worked a few different occasions that lil trick, good luck)

[DEVIL]

wow in the side of Europe where u ppl are, is veri expensiv to get a'n AC, in Romania a 10 Kw, whould be 1500 USD and that one with a pipe lenght of up to 20 m i should admit not a extreamly good brand

[mick2me]

B&Q it! Don't do it

Actually, and I hate to admit this, but I bought some
B&Q brackets. They are extremely strong, rated at 60kg load bearing. More than enuf for the Dakin @ 30kg

The only problem they hold the Daikin too far from the wall, the inside bolt slots are too far from the wall. as you can see. Perhaps the "Air f'(a)rce" unit needs a lot of clearance?

I tried to re-drill them to move the fixings back but found that they are stainless steel and burned out three drills without much effect on the thing. (I think the bolts are also Stainless)Cutting off the bracket ends with a hacksaw would be nigh on impossible for me. I am awaiting a contact in an engineering firm to drill four fixing holes (or slots) and cutting down the brackets.

Also I assume that moving the unit back on the brackets increases the brackets load bearing capacity threshold.


IMAGE
http://www.nottstalgia.com/images/brackets.jpg

[Slim R410a]

Brackets I use on domestic jobs, costs alot less than b&q ones too!

[mick2me]

Neat Job

What are they, and how many wall fixings?

[Brian_UK]

Mick, don't forget the wall/air clearance required at the back of your units.

You need a certain gap for two reasons:-
1. To ensure good airflow onto the coil.
2. So that you can clean the coil of dust and debris when it needs it.

[mick2me]

Mick, don't forget the wall/air clearance required at the back of your units.

You need a certain gap for two reasons:-
1. To ensure good airflow onto the coil.
2. So that you can clean the coil of dust and debris when it needs it.

Thanks Brian

Daikin Recommend 50mm to back of unit from wall.
I will give it 85mm.

[frank]

Thanks Brian

Daykin Recommend 50mm to back of unit from wall.
I will give it 85mm.

I think Daikin recommend a MINIMUM of 50mm

Leave enough space to get your hand and brush down. A clean condenser will save you money on the electricity bill

[mick2me]

I think Daikin recommend a MINIMUM of 50mm

Leave enough space to get your hand and brush down. A clean condenser will save you money on the electricity bill

Yes good advice Frank.

SWMBO has complained tonight that she caught herself on the bracket, whils pulling the hose round to the front garden

What do you recon to these cleaning tools?

[frank]

SWMBO has complained tonight that she caught herself on the bracket, whils pulling the hose round to the front garden

How did she get out of the KITCHEN???

[mick2me]

How did she get out of the KITCHEN???

I was doing the washing up!

[rbartlett]

Brackets I use on domestic jobs, costs alot less than b&q ones too!

Outdoor isolator??

cheers

Richard

[mick2me]

I would also suggest some mechanical protection for the cables as well. Also sunliight will break down the insulation. See my post about use of 20amp disconnector switch and flexible conduit.

[Slim R410a]

I knew someone would point out theres no isolators.
The customer did not want isolators, and, as in the pic you will see next to each indoor is a 20A dp switch which both run off there own 16A breaker at the board.


Mick, they are just cantelever arms fixed straight in with 4 10mm sleeve anchors, only do this setup on domestic jobs whereas normally bolt the arms onto 40x40 unistrut.
And I do always use an isolator on the outdoor. (and indoor on the likes of cassettes etc)

[Cofreth]

Isn't it better to have the isolator switch mounted on the wall than on the unit itself?

[rbartlett]

I knew someone would point out theres no isolators.
The customer did not want isolators, and, as in the pic you will see next to each indoor is a 20A dp switch which both run off there own 16A breaker at the board.


Mick, they are just cantelever arms fixed straight in with 4 10mm sleeve anchors, only do this setup on domestic jobs whereas normally bolt the arms onto 40x40 unistrut.
And I do always use an isolator on the outdoor. (and indoor on the likes of cassettes etc)

I don't think that the customer would be able to dictate what is/is not good electrical practice as governed by part P and what you have written about the supply(s) can only be done under part P regulation.

the electrician/air conditioning installer is possibly now liable to prosecution as it does not conform..be careful

Cheers

Richard

[mick2me]

I prefer the Disconnector on the wall.
Cable back entry, sealing the hole against weather.
Feeding the cables to the inverter via a flexible conduit.

Those Disconnectors I was quoted £19.50 +vat.
I got mine off ebay, new, for £6 including postage.

I really like those brackets though.
And 10mm sleeve anchors are my favorite fixing.

[Slim R410a]

ALL the electical work was done by an electrician, why does it not confirm and what do you mean it can only be done under part p if it was done by a part p registered installer!??

I wont bother posting up pics of my installs up anymore if I just get treated like someone who has bought a split off ebay and fitted it themselves

[slingblade]

ALL the electical work was done by an electrician, why does it not confirm and what do you mean it can only be done under part p if it was done by a part p registered installer!??

I wont bother posting up pics of my installs up anymore if I just get treated like someone who has bought a split off ebay and fitted it themselves

Like my old man used to say, "if the customer wants the sky painted pink then we shall paint the sky pink". if they did not want isolators then that is thier choice i suppose. an isolator within 1 mtr of rotating machinery would be prudent though i think to save peoples limbs from possible detachment.

[Andy]

ALL the electical work was done by an electrician, why does it not confirm and what do you mean it can only be done under part p if it was done by a part p registered installer!??

I wont bother posting up pics of my installs up anymore if I just get treated like someone who has bought a split off ebay and fitted it themselves

Cheer up bud

nice installs, isolator or not

Kind Regards Andy

[Slim R410a]

Cheer up bud

nice installs, isolator or not

Kind Regards Andy

Cheers Andy, much appreciated, at least someone has something good to say.

[frank]

I've got to agree that it is a nice neat install.

BUT - If you install any electrics that do not conform to the regs you leave yourself open to prosecution. It doesn't matter what the customer wants - he's not qualified to dictate.
Would a Corgi guy install to what the customer wants or to the regs??

If you install electrics that result in someone being electrocuted and death occurs then you WILL spend a long time in jail - no defence in law.

Although BS7671 is not law, if you can prove that you installed to the regs then you at least have a defense.

[mick2me]

I have to agree where electrics are concerned, you really need to know what you are doing.

However I hope people are not reluctant to post images of their installations, due to having them nit picked over.

Constructive Criticism should be a good thing for an installer at any level. Keep the images coming, I for one enjoy to see them.

[Brian_UK]

Yes, a nice install and without getting into the Regs regarding the electrical side I do however have one comment.

The fitting of the external isolator onto the condensing unit casing is one of the most annoying things to me. Any work within the casing now involves having the isolate the electrics at the power source so that the isolator can be removed from the casing.

If the isolator had been fitted to the wall it could have been switched off and locked off then the final unit connection cable could have been disconnected. It can then be moved clear away from the unit to improve the working area.

OK guys, rant over, tin hat on and fireproof suit fitted.

[Andy]

Yes, a nice install and without getting into the Regs regarding the electrical side I do however have one comment.

The fitting of the external isolator onto the condensing unit casing is one of the most annoying things to me. Any work within the casing now involves having the isolate the electrics at the power source so that the isolator can be removed from the casing.

If the isolator had been fitted to the wall it could have been switched off and locked off then the final unit connection cable could have been disconnected. It can then be moved clear away from the unit to improve the working area.

OK guys, rant over, tin hat on and fireproof suit fitted.

Once I had a freezer condensing unit trip out. Spark fitted the isolator on the wall, one of those fancy mock stone walls, didn't bother sealing the back of the isolator where the wire came through the wall. Yes water cooled electrics.

I LIKE TO SEE THE ISOLATOR SCREWED TO THE UNIT

Doctors differ patients die

Best place for the isolator is screwed to the unistrut bracket on some cable tray, all cable entries on the bottom

Kind Regards Andy

[mick2me]

I did post regarding the importance of sealing cable entry(s) to the disconnector switch. The same applies to back entry if fitted on the AC unit.

Based on what I have seen from my Daikin unit, I prefer the wall mounting method, It looks better IMO, and is less likely to be damaged. When I complete wiring on mine I will post images here.

[Slim R410a]

9 out of ten a/c units i see have the isolator pinned to the side. Where do you put it when youve got condensers on a flat roof?

The spark told me that the indoor switches were enough as it is still classed as local. Whether he is right or not I wasnt to know, but I will be providing my own isloators if a spark does this again next time

Thanks for all the comments, I take alot of pride in my work and take pics of every install. I am still not out of my time so I am making a 'portfolio' for future jobs/new customers to see exactly what they will be investing in etc.

Its good in a way that people snag your work, but in this case there is nothing to snag on the a/c side of things, only electrical which was done by others.

Thanks

[mick2me]

Glad you are proud of your work, and can accept constructive criticism.

On a roof with no adjacent wall would be a case where I would mount the Disconnector on the unit.

Actually the person most likely to use it in an emergency is ..... The Engineer

Actually mounting it on the unit is more difficult than a couple of rawlplugs in a wall, and makes internal wiring more dificult, especially if you need to disconnect the unit for removal for any reason.

I was gonna drill a hole in the bottom of the inverter Pipe connection cover and put a gland on the end of the flexible conduit and take the cables in that way. But no I decided just to enter in the gap for the pipes with the conduit, no gland, and tiewrap it all together.

Drill my Daikin! NO FEAR!

[frank]

The spark told me that the indoor switches were enough as it is still classed as local. Whether he is right or not I wasnt to know, but I will be providing my own isloators if a spark does this again next time

To be classed as local and to comply with regs it should be within 2m.

Keep up the good work

[mick2me]

Actually this thread seems to have wandered from Bossmans original topic. Could do with spliitting at my post about brackets? (moderator?) 'Brackets and Electrics'

Sorry Bossman

[Brian_UK]

Actually this thread seems to have wandered from Bossmans original topic. Could do with spliitting at my post about brackets? (moderator?) 'Brackets and Electrics'

Sorry Bossman

Don't worry Mick, a lot of threads go for a wander sometimes and then come back all by themselves

[Brian_UK]

This is addressed to you Mick for a "Things to watch out for" with your upcoming project.

When bringing cables into the condensing unit be aware of the possibility of cables resting or rubbing on pipework, especially 'hot' pipework.

It is not unknown for a cable to suffer heat damage when resting against a compressor discharge pipe at say 85°C and short circuit through the pipework.

The tripped MCB and burnt cable is bad enough but the arc against the copper pipe often creates a hole and your refrigerant charge disappears very quickly.

Also have a look to make sure that any of the manufacturers cables are correctly positioned just to be on the safe side.

[mick2me]

Thanks Brian, What do they say...

Insulation, Insulation, INSULATION.

Or am I thinking of something else?

[The MG Pony]

Conduit is our friend, same with nice component boxes that are sealed

[mick2me]

Conduit is our friend, same with nice component boxes that are sealed

Can't fault you for being tight on electrical side