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Testing Electrical Capacity of New Offices?
An anonymous reader asks: "Running a small graphic design studio, we've hit a snag that I'm sure many tech-reliant small businesses have hit before: our small flock of file servers, multi-processor machines and 22" monitors draws more electricity then the wiring in our current space can take. We're looking for a new space for this and other reasons, and as we look around we're generally forced to take the word of landlords as to what sort of amperage an electrical system can provide. Does anyone in the Slashdot community know a reliable way to test and see if an electrical system can support the needs of a computer-reliant business?"
Bringing a qualified electrician along when looking for new office space. Or at least having an electrician give it a looking over before you sign a lease. They should be able to look at the power coming into the building as well as the current distribution system within the building and give you some idea as to whether or not it could meet your needs.
Total available amperage to your offices doesn't always do you a whole lot of good if you can't get the circuits you need to your server rooms. Be sure to discuss with the landlord any plans you may have to add or move existing circuits around.
Ask to see the breaker box that holds the breakers to your office space. The amperage that will trip each breaker should be printed on it. If it's not clear which breakers go to your office space (perhaps because there's one big box for the building and it's not labeled well, or there are different boxes for each office and they're not labelled well, either), ask the landlord.
Put in the lease that the electrical system in they office space will have a capacity of X. Have a clause that says that if this isn't the case, the landlord will spend his own money to fix it in X weeks/months/etc, and if he doesn't then you get free rent until he does, as well as the option to break your lease without penalty. Be willing to pay an electrician to check that the max amperage of the space is what it's agreed to before you sign the lease, though. Also make sure the lease allows you to have an electrician come in and do said checking.
If you're really worried, put a significant penalty into the lease if the amperage is too low (I'm sure you don't want to move any more than you have to). You will probably have to pay a little extra for this. If your landlord balks at this, tell him to get an electrician who will back his work do the inspection, so that the electrician pays the penalty and the landlord doesn't.
Cover your butt. Bernard is watching.
Have everybody bring in their microwave when touring offices. When they say it'll support situation X have people walk out their car, grab microwave, and plug it in. See if they're still confident in supporting that load. If they are, flip 'em on.
Nothing beats proof you can actually see. Just figure out what how many microwaves you need to simulate your load.
One good dummy load would be a bag full of travel-size hair dryers. They pull roughly 1500-1700 W apiece, and they don't take much room. You could plug a whole bunch of them in and see if you lose breakers; if you have 5 KW of server demand I'd go for about 7 KW of dummy loads for testing.
Note that this is over and above checking the ampere ratings on the breakers for the circuits in question. You don't necessarily know what's upstream, but like any other part of your production system you want to stress-test it before you rely on it.
Scientists restrict study to entire physical universe; creationist
I'd assume you're using CRT screens.
LCD's to the rescue!
A good 21" CRT is going to suck down 110watts+, an LCD will probably do 30...
Plus, If each of them are 4 square feet, thats 88 sq feet less office space, or one more cube.
You may also want to check how easy it will be to keep the rooms cool without adding too many electrical systems. If the airflow in the building isn't sufficient, you'll be drawing much more juice in summer.
Of course, depending on where you are, you may have the same issue in winter with isolation and portable heaters. If you use AMDs, this won't factor as an *extra* load, though.
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>>Ask to see the breaker box that holds the breakers to your office space. The amperage that will trip each breaker should be printed on it.
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Really?
If the last electrician "installed" extra breakers in anticipation of future needs, (i.e. you've got switches without connecting wires,) looking at the box won't do you any good.
This is another reason why you should have a licensed electrician test the required electrical capacity prior to signing a lease.
The last two facilities I was involved with had to be upgraded. The first, because when we installed UPS' the heat from the UPS' overwhelmed the air conditioning.
The second because when an open space was suddenly converted to cube space, employees brought in a boatload of space heaters and pop-goes-the-breakers.
With regard to landlords putting guarantees in the lease, good luck. Many will tell you it's between you and the local utility and the most they will do is provide their "best efforts."
What you can OFTEN do is have your licensed electrician kill two birds by scheduling a representative from your local utility to meet with him when he inspects the site. At that time, any problems with the local power distribution grid THAT THE LANDLORD MAY NOT KNOW ABOUT can be identified.
With regard to estimating your needs, a google searches that include btu, kwh, "load estimation", etc. provides lots of links to help you develop a spreadsheet of what you need.
Live Long and Prosper - Thanks Leonard. You are missed.
Go buy a handful of These. Each one in parallel should draw ~1.0-1.3 Amps across a power jack, and scare the living crap out of whoever's showing you the office.
Or if you're feeling cheap, use These but don't leave them powered for more than 5 seconds. (read the datasheet).
If you are moving into a new space, you should have a construction allowance built into the lease. This will cover reconfiguring the office space and changing the electrical & mechanical systems. Why worry about mechanical systems? Because if you are going to need an electrical upgrade due to increased power consumption, you will need upgraded HVAC.
Before the lease is signed, get a design done and get bids on the work. The bids will give an honest account of the suitability of the space. You can now back out or go forward. If you go forward, negotiate the lease terms and the maximum cost of construction.
The work gets the work done by contractors, bills get paid by the landlord, you pay for it in your lease and it comes under operating expenses instead of capital expenditures - your accountant will love you (after they curse you for the up front hassle)
"As God is my witness, I thought turkeys could fly." A. Carlson
Oh, this is easy to fix. We had the same problem at a small 4-story office rental.
You need to bring in power from an outside source. Due to electrical codes, and the questionable ability of your existing wiring, I recommend the following procedure.
First, you need to rent some space in an adjacent property. Preferably at the same height from the street as your current property.
Then you need to buy 10-20 large microwave ovens, approx. 50 feet of copper tubing (like you can get at the hardware store), a set of wrenches and screwdrives, and 10-20 metal (not plastic) trash can lids.
Unfortunately I can't go into more details due to the gag order but I think you can figure it out.
Our power problems are solved. However we had to give up WiFi. On the plus side, our coffee is always hot!
Hope this helps.
You need a heavy duty multimeter. You can get one with a rating of about 20 amps AC for under $50. like this for example.
Hook the multimeter up with a variable resistor (also rated for 20 Amps) in series with the circuit you want to measure.
(+)-->resistor-->multimeter-->(-)
Open up the resistor (slowly) until the circuit breaker or the fuse goes. Note the amps that this happened at. That's your max.
Use ohms law to figure out power consumption. e=i*r volts = amps * ohms or p=e*i Power(in watts) = volts * amps Oh..... Just go here: http://www.grc.nasa.gov/WWW/K-12/Sample_Projects/O hms_Law/ohmslaw.html
or here:
http://www.knovel.com/knovel2/Toc.jsp?BookID=687
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