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  #11 (permalink)  
Old November 26, 2009, 08:33 AM
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Originally Posted by MpG View Post
Do you have a bunch of electric motors running or something? Giant electromagnets in operation? Running a mini iron-smelting operation?
Not quite. I do have a large number of computers, and have had upwards of 40 or so. So yeah, I do have a fair load and have dedicated multiple circuits for the computers and the associated cooling.

I do understand now that the battery life in Consumer UPSes are going to be poor pretty much regardless of actual UPS usage. So lets pull out Batteries and expected lifetime out of this thread and focus on the other question:
So yeah, my original question still sort of technically stands. How much better is a power line conditioner at holding the voltage stable over a consumer-grade UPS. MpG mentioned that spikes and ripples are harder to handle and that still makes me wonder about the 10V jumps (step up) and then the drops back down to "normal" a second or two later every time my AC kicks in. That's gotta be harder than just letting it sag a few volts overall for the couple seconds.
What method is used to maintain the static voltage, and is it the same method as consumer grade UPSes with large step up / down methods.
edit - fixes... tired typing

Last edited by DougTheSlug; November 26, 2009 at 08:39 AM.
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  #12 (permalink)  
Old November 26, 2009, 09:15 AM
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Originally Posted by DougTheSlug View Post
Hey Braineater,
Some of that explanation on Power Factor goes a bit over my head. But I'm also not sure what BC Hydro can do if my devices pull power in at a low power factor.
I'll do my best to explain.

Loads such as inductors and capacitors are capable of storing energy.

As this energy is absorbed/released with every cycle of the AC sinewave , it causes the voltage sinewave and the current sinewave to lose syncronization.

With Inductive loads for example , the voltage 'leads' the current......With Capacitive loads , the current leads the voltage.

-----------

The bottom line is this ;

If you have a lot of inductive loads , you are going to get large voltage fluctuations when these devices start.(like your AC)...

The solution (BC Hydro may or may not help you with this) is to install Capacitors on the main line to compensate for the inductive load.

Now technically , this could fall under the "Line conditioner" category , but it really isnt.

It's also not something you can do yourself , there is testing/inspections/etc involved.
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Old November 26, 2009, 12:01 PM
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Originally Posted by Zero82z View Post
0.6-0.7PF is typical for PSUs with no or passive PFC.
I'm aware of that, but...
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Originally Posted by DougTheSlug
I know all my top end machines have Silverstone PSUs with APFC
Unless something has gone terribly wrong with all the PSU's, I wouldn't expect that to be the source of the low PF. Doug, out of curiosity, do you get the poor PF only when the AC is running? Or all the time?

I was looking around regarding that conditioner, and I haven't been able to find any better details on the voltage regulation method used by them. As has been mentioned, a dedicated power conditioner will usually do a better job of fine tuning things than a regular UPS, but I couldn't find any documentation at this time to verify it for you. But yeah, a line conditioner is a band-aid solution, and without better documentation, it's hard to say whether it's up for compensating against a heavy induction motor starting up. When what you probably need is some caps installed to balance out that AC motor.
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Old November 26, 2009, 12:56 PM
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Unless something has gone terribly wrong with all the PSU's, I wouldn't expect that to be the source of the low PF. Doug, out of curiosity, do you get the poor PF only when the AC is running? Or all the time?
To be honest, I couldn't tell you. It's been so long since I've looked at power consumption using my killawatt for anything meaningful because I know it's so inaccurate. Right now it's been connected to my AC for 6 months now just monitoring the kWh being sucked in. I'll check the pf with and without the compressor running on the AC tonight if I remember.
For reference, I may even be remembering PF values I had before any of my latest machines even existed, before APFC was a common feature in PSUs. (ie: back in the days of 32-bit CPUs like the athlon XPs)

Braineater, thanks for that explanation. Between reading portions of that wiki page a few times and your explanation, I guess I can understand what's happening from a high level point of view, and why caps at a distribution node might help.
Not too sure why there isn't anything I can do about it. Or is the size of the equipment just too big to be able to manage from a consumer perspective?

Lastly, should the PF be consistent across all devices on a circuit? Or should I be getting different PF readings for each device I attach my killawatt meter to based on what that particular device is doing to the circuit?
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Old November 26, 2009, 01:12 PM
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Originally Posted by MpG View Post
But yeah, a line conditioner is a band-aid solution, and without better documentation, it's hard to say whether it's up for compensating against a heavy induction motor starting up. When what you probably need is some caps installed to balance out that AC motor.
That's what I've been assuming I'm going for this whole time: a band-aid solution. I never expected to get anything better from what's coming into the house, so it's up to me to try and do the best I can with what I'm being provided.

Will a line conditioner really help against a high inductive load? Or is there something else at work here that a line conditioner can't really manage on it's own? What if I put a line conditioner between the wall and the AC. Would that at the very least prevent much of the interference from getting back into the rest of the house causing sags elsewhere? Or would I be putting line conditioners on every else to separate them from the main line?
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Old November 26, 2009, 07:15 PM
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Originally Posted by BrainEater View Post
I'll do my best to explain.

Loads such as inductors and capacitors are capable of storing energy.

As this energy is absorbed/released with every cycle of the AC sinewave , it causes the voltage sinewave and the current sinewave to lose syncronization.

With Inductive loads for example , the voltage 'leads' the current......With Capacitive loads , the current leads the voltage.

-----------

The bottom line is this ;

If you have a lot of inductive loads , you are going to get large voltage fluctuations when these devices start.(like your AC)...

The solution (BC Hydro may or may not help you with this) is to install Capacitors on the main line to compensate for the inductive load.

Now technically , this could fall under the "Line conditioner" category , but it really isnt.

It's also not something you can do yourself , there is testing/inspections/etc involved.
This. The only problem with having a highly variable load and largely inductive, is that adding capacitors could have a negative effect on the outcome if they add too much (voltage under low loads could be super high). You cannot add a capacitor of that size that is variable, otherwise it would be very expensive. The point of these devices is to provide power factor correction, albeit PFC can be quite expensive. It's getting better, but it still bumps the price up with electronics quite a bit.

Having a higher PF can increase efficiency as well, since more real power will be available for use from the total apparent power. Adding capacitors will reduce the inductive losses from both the wiring in your home and from the inductive loads that you use (vacuum, dryer, stove, high load computer). Keeping your voltage up is key.

The great thing about today's PSUs and electronics is that many can stabilize the voltage and frequency on their own. Usually on a PSU it will say it can handle frequencies from say 45Hz-70Hz because the capacitor and inductor inside them can store enough energy to make a pure continuous DC signal (or close to it) over one cycle. However, losing the power source can have some serious effects by introducing harmonics and voltage spikes/sags on startup, and can harm the devices. This is why it is almost essential to use an uninterruptible power supply to reduce those harmonics and sags/spikes. As the electrical network expands beyond its limits, brownouts and faults will appear to be more likely.

I can go more into faults and protection if you'd like, but that's a whole topic on its own.


I wouldn't worry about 10V in sag when using a computer. 110V is still highly usable, as a PSU would use a boost converter to raise the voltage slightly. Now if it were 90-100V, then we'd be having issues, which could go all the way back to the main feeder from the transformer outside your house.

As people have said, a line conditioner gets rid of things that aren't wanted, like harmonics. It's not so much a voltage regulator, as it not only provides regulation for that, but also for current.
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Old November 26, 2009, 07:25 PM
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Originally Posted by DougTheSlug View Post
That's what I've been assuming I'm going for this whole time: a band-aid solution. I never expected to get anything better from what's coming into the house, so it's up to me to try and do the best I can with what I'm being provided.

Will a line conditioner really help against a high inductive load? Or is there something else at work here that a line conditioner can't really manage on it's own? What if I put a line conditioner between the wall and the AC. Would that at the very least prevent much of the interference from getting back into the rest of the house causing sags elsewhere? Or would I be putting line conditioners on every else to separate them from the main line?
A line conditioner will not help with a high inductive load. The only thing it does is get rid of the gunk in the power source.

If you want to run such a high load in your home, you should really get a technician over to inspect the power straight from the transformer, since they may need to add something not to your house, but for others using the same transformer as well. Contact your local distribution company for information. It could just be that you need simple capacitor fix.
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Old November 27, 2009, 01:40 PM
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A line conditioner will not help with a high inductive load. The only thing it does is get rid of the gunk in the power source.
Is that right? I thought decent conditioners at least had limited PFC ability.
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Old November 27, 2009, 02:39 PM
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Of course, but that's not to say that it can handle a very large inductive/capacitive load. Besides, he's losing voltage because of the load, regardless of whether it's inductive or capacitive. I-squared R losses will be much larger with higher loads, so a lot of potential will be lost along the electrical wiring.

A capacitor may do fine, but he may need to put a better service in or use a thicker gauge of wire to reduce line losses.
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