APC Advice

MichaelS wrote on 1/21/2006, 7:36 PM
Well...for the first time, our studio took a hit from a power surge. Suddenly, I'm thinking that a professional grade surge protector and backup power supply sounds reasonable. Duh...

Although I had cheap surge protectors on my system, it still managed to burn out some critical circuitry. Fortunately, my computer was still under warranty and a new mobo is on the way.

I'd like some suggestions on affordable APC units. I checked out the shelves at Circuit City today. No real choices. What should I look for? What are the minimum requirements for a standard editing system?

I'd appreciate the help!

Comments

farss wrote on 1/22/2006, 12:05 AM
Do you want just surge protection or a UPS as well?
The best place for surge protection is in the main switchboard where you have access to the best possible earth connection. The idea is to divert the surge to earth as cleanly as possible without having the earth point itself jump up in voltage due to the current flowing down it.
The next thing up from surge protection is a line conditioner, typically a constant voltage transformer. These provide both under and over voltage protection. The undervoltage protection is only for a few cycles but that's as long as many of them last.
A full blown UPS gives long term power backup from batteries. The main criterion here is how long you need to keep the system running for, most of the cheaper units can only manage 5 minutes, just long enough to elegantly shut the computer down. Even with a UPS surge protection in the main switchboard is a good investment, the energy levels involved in major power glitches can be too much for most desktop UPSs to handle.
Remember that many surge protection devices can be destroyed in the process of shunting the surge, the ones that get fitted to local switchboards have an indicator to let you know it's time for a new module.
Bob.
MichaelS wrote on 1/22/2006, 8:03 AM
Bob,

As always, thanks for the good advice!
John_Cline wrote on 1/22/2006, 8:15 AM
I run the one in the following link from APC on my editing system. It will run my PC, two 21" CRT monitors and a 14" broadcast monitor, plus all the other little stuff for around 20 minutes. It also has software that will shut the PC down gracefully if there is a power blackout that goes for more than 20 minutes when I'm not around. It also has a voltage regulator in it that will compensate to over/under voltage. It's relatively cheap insurance.

APC RS1500
johnmeyer wrote on 1/22/2006, 8:22 AM
Beware of surge protection products. The vast majority of them are pretty close to snake oil. If you look inside a "surge suppressor" power strip, it usually only contains a varistor, which is a semiconductor component that can absorb extremely short duration spikes of power (a few milliseconds). Really big surges, which happen during momentary power outages, or if two phases of power suddenly get shorted together or -- worst of all -- a nearby lightening strike, are going to completely overwhelm such devices. Since these are the only things that damage most equipment (the power supply for many devices already protects against the little spikes), you're pretty much wasting your money when you buy surge supressor power strips.

The only way to protect against the big hit is to invest in equipment that completely regenerates the AC voltage. The most affordable of these is the "always on" UPC (or APC). You have to read the labels really carefully to make sure how the device operates. Most cheap (under $100) UPCs simply quickly switch over to battery when the power fails. The rest of the time, the power is sailing straight through from the power company. These will not protect you from most power surges.

However, the expensive ones always have the "inverter" running. These devices take the 120 VAC (or 240 outside the U.S.), convert it to 12 VDC, and then chop it up and create a new 120VAC signal. The input and the output are completely decoupled. If there is a big surge, the front end of the UPC gets fried, but nothing gets through to the output because they are not electrically coupled.

Such units usually advertise that they will supply constant voltage even during a brownout (another big benefit).

The really expensive versions of such devices can be found through places that supply the home theater market. Many of the $100,000 and up big-time home theater installations create their own power system in order to eliminate ground loops. These power supplies recreate the 120VAC power in an extremely "clean" way (i.e., very smooth sine waves, with no distortion). They are quite large and can cost as much as a small car. However, they are extremely effective.

MichaelS wrote on 1/22/2006, 10:04 AM
Thanks John² .

As a forewarning for others, here's what happened.

Although we always "disconnect" during thunderstorms, it never crossed our minds that "wind" would be a problem. Because we had recently had an ice storm, many limbs were hanging loose on trees.

On a particularly windy day, a limb fell across a power line/pole, shorting the circuit momentarily and sending a surge down the line.

Hindsight being 20/20, I plan to install a UPS safety device next week. Fortunately, no harddrives were damaged, but the downtime has been quite costly.

You live and learn...a lot!

Thanks.

Coursedesign wrote on 1/22/2006, 10:16 AM
When you buy a surge protector of any kind, always look for a 330V rating rather than the cheaper 400V rating (these numbers are for 100V mains only!).

This is the voltage at which the varistor fires (i.e. changes from being an isolator to being a conductor to short the input), and the difference is crucial for electronic equipment.

Next, the joule rating which is the amount of energy the varistor can absorb before going up in smoke.

I saw a package of two 330V surge protector strips rated 2550 Joule each at Costco yesterday for $15 for the pair. Didn't have time to check out the overall quality but at first glance this seemed not bad.Practical features like cable management and more, too.

You can also go to any of the Big Box stores and buy Monster Cable "High Definition Surge Protector Power Strips" for well over $100 each. :O)

(And don't forget to pick up your $49.50 "High Definition TV Microfiber Dust Cloth" while you're there...)