[nylug-talk] Cleaning dirty power

[vin]

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On Tuesday 06 June 2006 10:49 pm, Michael Bacarella wrote:
> How do I turn this monster called wall power, complete with
> hardware frying power drops and lightning surges into something
> that will never harm computer equipment again?
>
> I used to have an issue with power drops frying my power
> supplies, so I put in an offline UPS to smoothen those
> out.  Every so often I'd hear them click on for a split
> second, and I'd know my hardware was saved.  I thought I
> was safe.

I've got a couple UPS that so far have survived some rather fierce lightning 
storms (and a water pump that didn't).  My computers run 24/7 so I don't have 
the luxury of shutting them down quickly, there are too many things running 
on them, or they're acting as servers.  Both of my UPS also "line condition" 
thelines, which is probably the "clicking" you're hearing.  When the voltage 
drops, the UPS kicks it back up to its acceptable range.  When there's an 
overvoltage condition, it kicks it down to the proper range again and 
maintains it there.  

Being at the mercy of ConEd, you have to have some protection, as I've learned 
the hard way.  ConEd simply can't deliver consistent voltage, it varies too 
much.  During the summer they intentionally reduce voltage (though they 
completely deny this) in an effort to shed 230 volt and larger equipment. at 
their customers' premises.  Once they shed these loads, it takes 3-5 minutes 
or longer for the equipment to come back on line automatically, but for the 
customers who know and understand what ConEd is doing, they manually 
intervene and shut down the equipment for much longer periods in an effort to 
prevent their equipment from becoming damaged. ConEd relies on these 
compressor shutdowns and manual intervention in order to shed load and 
continue providing electricity, rather than to blackout an area completely.

The damage occurs either during the "brownout" when ConEd is reducing voltage 
and your equipment goes undervoltage (if not protected against this, your 
equipment can burn out or spontaneously burst into flames as I've seen some 
equipment do during an undervoltage situation), or when the voltage is 
brought back to normal, which may result in a surge prior to the current 
stabilizing.

Some UPS also "line condition", some don't even though they are battery 
backups.  Also, although it's been a while since I read up on them, some UPS 
are able to continue powering your devices when the power goes out including 
during the switchover to batteries, and some UPS actually are interrupted for 
some milliseconds as they switch over to batteries.  The former are a better 
design and probably more expensive, and probably found in the higher end UPS.

The surge protectors have ratings.  Pay attention to them.  If you own the 
house you are living in, or are on good terms with landlord and living a long 
time in the apartment you rent, you may be able to have an electrician 
install a surge protector at the electrical panel where the circuit breakers 
are located.  This would be your first line of defense.  Making sure the 
panel and your house/home is properly grounded is your second line of defense 
and will be taken care of when the surge protector is installed.  Then you 
can concentrate on a surge protector prior to your UPS (although one or more 
UPS brands have advised against this for whatever reason).

Also, I've had a situation where the house is provided 115 volt service, so 
there are two "hot" lines coming into the house and one neutral (like any 
house with 115 volt service).  Once so far this year, and two or three times 
last year, one of the "hot" lines has lost current while the other has kept 
current coming in.  This resulted in all the equipment on "bus A" in the 
electrical panel losing power, and all the equipment on "bus B" in the 
electrical panel continuing to be powered.  With the house, on one floor, 
whichever plugs happened to be fed from bus A  didn't work, and appliances 
plugged into plugs fed from bus B worked.  This resulted in a refrigerator 
continuing to run, but losing lights, televisions, vcr, air conditioners, and 
other equipment in other rooms.  Because I had a UPS on a computer, when I 
lost power there, I ran an extension cord into another room and plugged the 
UPS into the outlet in another room that had power.  Another computer on 
another UPS kept running because it apparently was fed by bus B.  So keeping 
an extension cord on hand that is 12 guage and long enough to reach several 
other rooms is a good idea.

The best advice is to find and ask a LUG located in a lightening prone area.  
Central/Southern Florida, especially in the Cape Canaveral area is known as 
the lightening capital of the US, or the world.  Ask a lug down there.  Or, 
find a company that installs computer systems or high end electronics in that 
area, and ask for what equipment they use to protect against lightening 
strikes.  It's going to be a multi-level protection plan, from outside 
lightening arrestors on roofs, antennas, poles, etc., to whole building surge 
suppressors at electrical panels, to individual outlet protection.  Ask for 
name brands, model numbers, and anything else you can get.  Perhaps an 
installation company for high end electronics will have a floor plan with 
brands and model numbers specified.  Ask for a copy of the pdf file.

Companies are going to give away their info for free in most instances, but 
maybe you'll be in the market for some of their surge suppressing equipment, 
like a panel surge suppressor (Home Depot sells one, doubt it would be the 
same as used by high end companies in Florida).  Or maybe you'll find a 
fellow GNU/Linux enthusiast working for one of the companies who doesn't mind 
sharing some tips.

> Just this weekend my brother's apartment (appears) to have
> been hit by lightning.  Every single hard disk his place
> has been destroyed.  Including the ones dedicated
> for backups (luckily he found some data burned to DVD).
>
> I was going to recommend my UPS, but Now that I look over
> the specs, mine, the APC Back-UPS CS 500, doesn't (appear) to
> offer surge protection on battery backed sockets.  Have I been
> vulnerable to power surges all this time?
>
> What kind of ultimate UPS do I want to put under my desk
> (and my brother's) to make these problems go away? 

There won't be an ultimate.  If its done right, it will have to be done in 
stages, large protection, smaller protection, smallest protection.

> It should have 
> the capacity for a fully featured workstation with printers,

You're not going to be putting a laser printer on a UPS.  At best, you'll be 
using multi-level surge protection, and if you're really serious, then use a 
big, commercial line conditioner which can handle the 1000+watt electrical 
demands of the laser printer without frying the line conditioner or UPS.  
Whatever your laser printer is rated at, it uses a much heavier load 
momentarily during each printed page. Keep the printer on a surge protector 
and turn on only as needed at least in the summer months, if possible.

> scanners 
> random network hardware, etc.

If you are planning on using a generator as a back up power supply for 
computers, make sure that you either have a line conditioner or a UPS with 
line conditioning capabilities built in between the generator and the 
computer or other sensitive electrical equipment.  Portable generators have 
terrible control over the voltage they put out.  They vary in output just as 
teh engine varies as it runs.  They surge as load is removed, they surge as 
the fuel is sloshed around, they surge just as they run out of fuel, etc.

If you are at the point of including generators in your backup plan, you may 
want to consider adding a battery backup after your UPS which includes 
battery backup units that use car batteries or similar sized deep cycle 
batteries as the power source.  The unit is a battery backup unit (computer 
UPS) which uses the car battery as its power source, and when the power comes 
back on, it charges the battery up.  Sealed, deep cycle batteries can be used 
(and charged) indoors without giving off gases during charging.  Don't have 
any experience with them, but they sound like a good idea capacity wise, 
especially if you'll need longer than the 15-30 minutes a UPS will buy you 
before you're able to get your generator fueled and running.  You can even 
run them in series (or is that parallel) to extend your run times.

While on the subject, for those of you purchasing air conditioners this summer 
or for the future, here's some advice I learned the hard way.  Find out what 
the electrical voltage requirements are for the units you are considering.  
If they all have the same or similar warranties and aren't suffering from a 
bad rap in consumer reports or elsewhere, then use the voltage ratings to 
decide after features.

Friedrich 115 volt air conditioners are rated +10% and -5% from 115 volt

GE, I couldn't get a straight answer, apparently 115 volt is the only voltage 
they work at, they won't work at 114 or 116 volt (quoting the GE Answer 
Center lady), which isn't right.  

Fedders, (which also makes AirTemp and Maytag) is rated at 108-115 for the 
model numbers I asked about, the high end is obviously wrong as well.

The models with the largest voltage operating range are going to be more 
tolerant of voltage variances, and the lower voltage number is important for 
ConEd voltage reductions.  

For 230 volt models, this information is more critical. Check Friedrich 
carefully.  The older models used 205 as their low number.  From experience, 
at 204 volts, the compressor kicks off and the air conditioner turns into a 
big fan blowing room temperature (and slightly warmer) air.  After replacing 
over 100 feet of 230 volt line with new line, replacing junction box splices 
with new ones, replacing the Friedrich with a Fedders rated at 195 volts at 
the low end and at least 10 or more volts higher at the high end, can't 
remember exactly what the high number was, and installing a much larger 
capacitor in the unit than stock, the Fedders unit which was rated at a 
higher wattage and higher btu (35,000) never kicked off its compressor, even 
during unofficial ConEd voltage reductions (as far as I checked, the voltage 
reductions never went below what the Fedders was rated at the low end).

If you can't get an answer from themanufacturer or the retailer, go to the 
retail outlet and for the 230 volt models at least, pull the filter cover off 
and look at the metal tag with the specifications on it.  It will list the 
low and high voltage ratings, for every 230 volt model.  Some 115 volt models 
may list the information also.  Looking at a Frigidaire(made by someone 
else), 115 volt model, they don't list this vital info on the label.

For anyone installing an air conditioner, if you know what you are doing, 
whether 115 volt or 230 volt, attempt to purchase and install a much larger 
capacitor than stock.  Johnson Controls in LIC, near the BQE carries them, or 
other electrical suppliers (wholesalers, or those selling to the trade) 
should carry them.  Only if you know what you are doing, or if you hired an 
installer and he's willing to do this. Because if you don't know what you are 
doing the capacitor can kill you.  What the capacitor will do is help "buck 
up" the voltage to a usable level when the voltage drops, similar to the line 
conditioner of a UPS. Someone in the oil supplier/commercial air conditioning 
industry showed me how to do this.  They do this in every commercial 
window/wall unit they install (and probably central units also).

vin.



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