Coping with server builds and only 32Amps to play with ?.

[RimBlock]

I currently live in a building with a 32Amp load limit at our consumer unit.

Whilst building servers for clients we have had the RCD trip and when we had the power circuits tested the bottom line was that we were close to hitting the 32Amp limit with regular use of items (TVs, Air Con, Home server, 2 PCs, XBox, Projector etc). With a wife and 3 kids all doing their own stuff most of the time it is not unusual to have many power sucking devices all running at the same time.

With more client builds coming in from time to time, I would like to be able to test and run without knocking the power out to our whole apartment .

Short of moving / getting the electric supply company to upgrade our feed (extremely expensive), is there any other way to help manage the load, possibly via a UPS for the servers ?.

RB

 

[Patrick]

That would be a big UPS! If you are doing short 20-30 minute bursts not an issue. I was having the same issue when doing 2P and 4P Opteron G34 testing a few years ago.

 

[cactus]

Getting a UPS is just going to protect you once the power goes out. You could charge it then unplug it from your mains line and use it as a power pack. It wont give you much work time though. Also note, a UPS will also pull current charging and, if you get an enterprise line-interactive unit, all the time.

It would be hard to get away with just 32A 230V. Heck, I have a welder running off a 50A 220V circuit.

 

[RimBlock]

Yeah, I was thinking more of being able to smooth out some spikes that may occur when starting a server and its hard drives which may just tip me over.

32A really is pretty tricky to work under some times. The irritating thing is that the government has been doing upgrading programs to the apartment blocks (most housing is Government owned here) and our old place got upgraded just before we moved out but there are no plans to upgrade this building yet.

Oh well .

RB

 

[ehorn]

Hello RB,

I can think of a few options:

Add power:
Build a genverter (inverter/charger/battery bank w/optional generator for backup loads/charging) to supplement demand. You can charge the batteries when demand is low and use when demand is high. This acts like a UPS but is more purpose built in that it can be sized for you power need. It will be separate circuits from the incoming mains and require you to plug your hardware into it when needed.. This option would likely be weighed against adding power at the mains.

Conserve power:
Virtualize and consolidate some of your existing gear to reduce power consumption.

Schedule power needs:
Tell the family when you will require power and boot them off their gear.. Not a particularly family friendly option.

 

[dba]

This may or may not be helpful:

I had a similar problem on my sailboat, which has a 30A shore power circuit. Usually that is enough power, but if the AC started up while other big loads were running, the breaker would trip. Everything could *run* at the same time; the problem only happened when the AC was just starting.

It turns out that our small AC unit requires something like 8A to run but 18A to start. It is the largest current draw on the whole boat - the same *may be* true in your apartment. Our solution was a wired-in box designed to reduce surge current in air conditioners. It's sold as a marine product, but it looks like it would work with any alternating current based air conditioner, including 230V 50hz.

Its called a Dometic SmartStart. URL is: http://www.dometic.com/cbcde79f-6594-4d01-b60c-2ab7e153c982.fodoc

 

[Patrick]

I had a similar problem on my sailboat, which has a 30A shore power circuit.

Not everyone runs an Oracle data warehouse operation on their sailboat

 

[cactus]

^^^Must be cramped quarters.^^^

Would love to see whats in that Dometic SmartStart. My guess is a uC controlled current limited starter maybe with a start capacitor. Anything with an electric motor is going to have high inrush current demands. It would help smooth current demand on warm days where your AC is cycling often.

 

[dba]

Nice one Patrick!

Actually, my wife has so many decorative pillows on the boat that: A) There is no room for servers - except that I snuck in a Mac Mini B) We'll never sink!
On the other hand, you should see my basement, which is devoid of pillows entirely but has more than its share of servers.

Not everyone runs an Oracle data warehouse operation on their sailboat

 

[Patrick]

Ha! Actually, my father is thinking about a 42" boat. He was thinking a catamaran until last night when someone at the dinner told him that even in redwood city it would likely be years to get an end tie for it.

 

[dba]

Leaving the 42 inch boat typo behind...

Catamarans and the SF Bay don't get along very well - there are very few slips available.

Does your father plan on using the boat as a home or a weekend getaway place or does he plan to sail quite a bit? If he's going to sail then Redwood City is a really bad place to have a boat. The winds down there are pathetic and it takes hours to sail or motor to the fun parts of the bay.

Ha! Actually, my father is thinking about a 42" boat. He was thinking a catamaran until last night when someone at the dinner told him that even in redwood city it would likely be years to get an end tie for it.

 

[Patrick]

Leaving the 42 inch boat typo behind...

Catamarans and the SF Bay don't get along very well - there are very few slips available.

Does your father plan on using the boat as a home or a weekend getaway place or does he plan to sail quite a bit? If he's going to sail then Redwood City is a really bad place to have a boat. The winds down there are pathetic and it takes hours to sail or motor to the fun parts of the bay.

Ha! Crazy morning as I think I mentioned on e-mail.

I think this is more of a 4th "home" for my parents that will go out on the bay 2-6 times/ year at most by year 3. Anywhere other than Redwood city would drop that number by half.

 

[dba]

Ha! Crazy morning as I think I mentioned on e-mail.

I think this is more of a 4th "home" for my parents that will go out on the bay 2-6 times/ year at most by year 3. Anywhere other than Redwood city would drop that number by half.

Well then I admire their insanity in contemplating a boat purchase. Insanity because I'd never take on that much maintenance - and a boat requires a ton of maintenance - for that few sailing days per year. Admire because as a sailor I'm glad whenever anyone chooses to get out on the water.

 

[Patrick]

Well then I admire their insanity in contemplating a boat purchase. Insanity because I'd never take on that much maintenance - and a boat requires a ton of maintenance - for that few sailing days per year. Admire because as a sailor I'm glad whenever anyone chooses to get out on the water.

My grandfather had a boat that we would go out on often. I'm thinking it is a genetic thing that I will catch at some point.

 

[dba]

My grandfather had a boat that we would go out on often. I'm thinking it is a genetic thing that I will catch at some point.

I hope that it does - and I can help by taking you and your significant other sailing!

 

[RimBlock]

Hello RB,

I can think of a few options:

Add power:
Build a genverter (inverter/charger/battery bank w/optional generator for backup loads/charging) to supplement demand. You can charge the batteries when demand is low and use when demand is high. This acts like a UPS but is more purpose built in that it can be sized for you power need. It will be separate circuits from the incoming mains and require you to plug your hardware into it when needed.. This option would likely be weighed against adding power at the mains.

Conserve power:
Virtualize and consolidate some of your existing gear to reduce power consumption.

Schedule power needs:
Tell the family when you will require power and boot them off their gear.. Not a particularly family friendly option.

This may or may not be helpful:

I had a similar problem on my sailboat, which has a 30A shore power circuit. Usually that is enough power, but if the AC started up while other big loads were running, the breaker would trip. Everything could *run* at the same time; the problem only happened when the AC was just starting.

It turns out that our small AC unit requires something like 8A to run but 18A to start. It is the largest current draw on the whole boat - the same *may be* true in your apartment. Our solution was a wired-in box designed to reduce surge current in air conditioners. It's sold as a marine product, but it looks like it would work with any alternating current based air conditioner, including 230V 50hz.

Its called a Dometic SmartStart. URL is: http://www.dometic.com/cbcde79f-6594-4d01-b60c-2ab7e153c982.fodoc

Thanks guys,

I will take a look.

Regards
RB