OT: Voltage Regulator. What do I need?

farss wrote on 11/9/2007, 11:54 PM

A proper UPS should cope but the problem is there's all manner of such things. Are you certain you're using a UPS or is it just a line conditioner.

The UPS should have a battery in it, typically a sealed lead acid type and the unit should be adequately rated, preferably on the higher side. I'd be looking at 1KVA to run a PC in your circumstance.

Bob.

John_Cline wrote on 11/10/2007, 12:05 AM

The APC "Back-UPS® RS" series of battery backup devices have automatic voltage regulation. From their site: "A distinguishing feature of the Back-UPS RS is automatic voltage regulation (AVR). AVR instantly adjusts both low and high voltages to safe levels, so you can work indefinitely during brownouts and overvoltage situations, saving the battery for power outages when you need it most."

http://www.apc.com/products/family/index.cfm?id=23&isoCountryCode=th

John

NickHope wrote on 11/10/2007, 12:35 AM

Thanks guys.

Bob, it's definitely a UPS. I have 3 of them. If I pull the plug out of the wall they work fine for a while, and in the past they've worked during power outs. But there's something about these recent spikes/failures that upsets them.

On the back they say 800VA / 400W which puzzles me because VA is W isn't it?

I should probably splash out on a APC import like John links to but I heard of people using voltage regulators in line before a UPS. That might be a cheaper and more flexible solution for me but I'm just not sure what I would need.

ChristoC wrote on 11/10/2007, 1:33 AM

Some UPS's are pretty simple and don't feature any power conditioning/regulation, but merely detect power loss; in your case it may well be cheaper to run all 3 from a conditioner/regulator.
BTW in AC supply VA and Watts are not eqivalent.

Google for: Power conditioner regulator
eg
http://www.general-electrical-appliance.com/power-conditioner/automatic-voltage-regulator.htm
http://www.elect-spec.com/pwrcondiz.htm
etc....

farss wrote on 11/10/2007, 4:08 AM

Watts don't equal VA unless the power factor is 1. At a power factor of 0.5 800VA = 400 watts. Most PC power supplies have a pretty bad PF so a 400 Watt PC power supply could be drawing 600VA but you'd still be in spec.

A bigger UPS than you need isn't a bad idea though, if nothing else the bigger battery gives you more time before you have to shut down in the event of mains failure. However maybe in your case the problem is caused by transients from things like tap changing in the local substation. Those kinds of transients can have a lot of energy and go right past the UPS or else the UPS just ins't fast enough switching over or the problem is in the design of the UPS itself, there's a number of different ways they can be built.

You could try a line conditioner before the UPS, a Constant Voltage Transformer is the best with good high frequency filtering and surge suppressors. If you can, ask around to see what your neighbours are using and if it's curing their problems. Things like CVTs are heavy and therefore expensive due to freight so best to be certain before you buy.

One simple thing, check your earth connections, right down to the earth itself. Lots of the protection devices try to shunt the nasties to earth but if the earth connection is no good they can do more harm than good.

Bob.

JJKizak wrote on 11/10/2007, 5:08 AM

UPS's are useless in your situation. You will need "exotic" solutions, one being a line transformer, next some "industrial filtrons" (very expensive and most people don't know what they are or what your talking about) and then possibly a good set of super duper MOV's for component protection. A donation to the power company might be a cheaper fix.
JJK

NickHope wrote on 11/10/2007, 5:12 AM

No earth connections here Bob! They just don't bother connecting earth in the buildings. Most people I know, me included, snap the earth pin of new Thai plugs so they'll fit in more sockets!

Thanks for the replies. I'll see what CVTs available in Bangkok or Phuket Town.

blink3times wrote on 11/10/2007, 9:04 AM

"No earth connections here Bob! They just don't bother connecting earth in the buildings. Most people I know, me included, snap the earth pin of new Thai plugs so they'll fit in more sockets!"
===========================================================

Heck... I'm in Canada and I snap off every ground prong I run into... hate the dam things.

4eyes wrote on 11/10/2007, 9:05 AM

A loud bang down the street & my computer locks up, that's funny (not to you though).
Some voltage regulators can be very loud ( electronic / mechanical )
I have 3 - 2kva Active UPS's.

There are 2 types of UPS's .... Active & Passive.
A passive ups the load is running direct from the source supply & switches to battery on power failure. ( I don't prefer these units )
An active UPS is always running from the batteries, basically keeps the battery charged, the battery feeds the inverter. There are a few different designs with Active UPS's, the theory is the same.

Use a laptop.
Buy a generator that runs on banana gas.

NickHope wrote on 11/13/2007, 2:55 AM

I'm starting to wonder if this is relevant...

In the manual for my Enermax Liberty power supply it says "...please use Sine Wave type UPS. This PSU is not compatible with Simulate Sine Wave type UPS".

My older computer, on a similar Thai-built UPS, does not crash when the power cuts, and I can't find anything about the UPS type in the manual for the power supply (Enermax EG365P-VE).

Anyone know if these typical Thai-built UPSs are "sine wave" or "simulate sine wave"? And does anyone know what type the APC UPSs are?

apit34356 wrote on 11/13/2007, 4:17 AM

Nick, "simulate sine wave" is a very common and simple way to convert a DC voltage to AC. Most all UPSs used simulated sine waves. IF the stepping "rectS", small square waves, used to build the AC sine way are too wide(too long in duration) or off-center,(creating large jumps in voltages), they will play kauso with a simple power supply design. You may have a "knock-off" UPS using a poor design.

farss wrote on 11/13/2007, 5:04 AM

We use a simulated sine wave inverter (500VA) to run lights off 24V batteries. It's a typical made in china unit. Cheap but works. Only problem is due to the high harmonics in the 'almost' sine wave output the ballasts in the lights are much more noisy.

You can check what the UPS has by opening the lid. If it has a large transformer in it then it's most likely a ferro-resonant inverter and they're pure sine wave.

If not look for a unit by APC or Powerware (used to be called Sola). Both those are pretty good, I used to work on the monster Sola UPSs, the nasty ones with a large room full of batteries.

Your lack of earthing reminds me of a trip we did through India. They're 220V as well and no earthing. Great until you have a hot water heater that's a bit old. End result is live water pipes, not pleasant getting a jolt from the tap when having a shower. Made me prefer hotel rooms that didn't have hot water.

Bob.

4eyes wrote on 11/13/2007, 8:46 AM

End result is live water pipes, not pleasant getting a jolt from the tap when having a shower. Made me prefer hotel rooms that didn't have hot water.That shouldn't happen if the electrical system is installed properly because on a grounded or ungrounded power source you still ground the building, electrical system and anything likely to become energized. This makes everything at the same ground potential, should be way less then < 1 ohm between all grounded equipment ( all electrical equipment or mechanical devices likely to become energized should be grounded/bonded). The electrical trade calls this grounding and bonding.
Ungrounded or grounded power sources, if the electrical system is installed properly you should never get a shock when a fault occurs in the system.
Lucky we have electrical inspectors & building codes.

Coursedesign wrote on 11/13/2007, 8:58 AM

I would start with adding a good quality (tens of dollars in the U.S.) transient protector (built into a power strip typically) before the UPS (between the power company and the UPS box).

For 110V, it should have a clamping voltage of 330V, for 220V make it 660V.

Cheaper transient protectors only clamp at 400V (in a 110V system), that is not sufficient for most PCs.

In addition to the clamping voltage rating, you would need to make sure to get one with the highest Joule rating you can find. The Joules measure the amount of energy the MOVs inside can absorb safely.

GaryAshorn wrote on 11/13/2007, 9:22 AM

The usual issue is as explained between the active and passive UPS systems. However, in active UPS systems the batteries are generally used as part of the filter circuit. So if the incoming power is really all that bad it could get past the filtration system. The Inverter output may or may not be synced to the incoming power or transfer purposes. Without knowing how the unit is really design it is a big guess to answer your question.

Gary

NickHope wrote on 2/5/2008, 9:48 PM

Well, I got an APC Back-UPS RS 1000. It's one of those tall thin ones. In the Power Chute software I had to set the sensitivity to "low" because the power supply here is so awful, but since then it's been working like a dream while all around it fails. Great piece of kit!

farss wrote on 2/5/2008, 10:19 PM

Looks good and plenty of power outlets. Now comes the fun part, finding IEC extension leads. They're very popular in Europe but a bit harder to find down here. Why I don't know, they're so much better when you've got lots of things to power up. Radio Spares sell IEC power strips which are also great as they takeup so much less room.

Bob.

akwaaba wrote on 2/5/2008, 11:36 PM

hi there Nick,
Woody's PC Group Therapy at The Sandwiche Shoppe, Patong this Sunday gives good advice for Phuketites.
They suggest everything, including your plasma TV, is run witha Voltage Regulator.
Most people find the recommended APC type best and buy them at "Super Cheap'.
Hope this helps.
Chris

akwaaba wrote on 2/5/2008, 11:44 PM

Sorry been sailing. forgot the date.....PC Group meet at the Laguna Shoppe this Sunday, and Chalong on 17th.
Chris

NickHope wrote on 2/6/2008, 1:59 AM

It came with 2 leads, but then at the moment I'm only using 1 of them as I'm only running my quad core off it. Monitors etc are run off my older UPS's.

Chris, I hadn't heard of that user group. I'll try and check them out and thanks for the voltage regulator tip.

seanfl wrote on 2/8/2008, 12:24 PM

I've run $150 ups's for years that still let big swings through.

my solution was to add a Furman power conditioning AR-1215 which does a great job of keeping it in the proper range.

http://www.fullcompass.com/product/301534.html

Sean

Steve Mann wrote on 2/8/2008, 2:59 PM

"No earth connections here Bob! They just don't bother connecting earth in the buildings. Most people I know, me included, snap the earth pin of new Thai plugs so they'll fit in more sockets!"

Nick, your UPS could be responding to a momentary ground fault caused by whatever caused the "bang" down the street. That third pin is much more important than people think. When things are operating properly, you wouldn't notice the missing earth ground, but when things fail, they can fail catastrophically and become dangerous.

What you need is a constant-duty UPS. They are a little more expensive than the standby UPS's that most of us rely on here in the states. In a constant duty UPS, your PC power is always supplied by the UPS. In a standby UPS your power comes from the AC line until the line drops out, then the UPS kicks in usually within a half cycle.

blink3times wrote on 2/8/2008, 4:31 PM

"When things are operating properly, you wouldn't notice the missing earth ground, but when things fail, they can fail catastrophically and become dangerous."

Naaah. I've always said that grounds are for sissies and inspectors. If you open your fuse panel and have a look, you will find the your ground and you neutral wire hook up to the same place. In other words, the ground wire is just another neutral wire.

The popular excuse for the ground wire is: "In case the Neutral wire breaks, the current has a place to go"... which is really quite silly when you think about it. I suppose if the neutral wire broke at the same time you threw the hairdryer in the shower with you in it.... it may make a good case for being there. But then count how many times in a given year that may happen.

What I find absolutely CRAZY is a bare ground wire (the way they quite naturally come) floating around inside a connection box. I can't even begin to tell you how many times I've heard an electrician curse as he pushes a new receptacle into a connection box only to hear a huge ZAP when that cute little BARE ground wire rubs up against the hot line.

GFI (Ground fault interrupters) are a much better way to go and in fact I believe they're pretty much code now in most of North America. And contrary to popular belief, they will function with or without ground wires.