Running electronics off a generator

[BillX]

Hello to All. This is my first post.

In rural areas there are more likely significant voltage fluctuations with power from the grid, and more than average power outages, some of them quite long.

I'm trying to find the best approach to running computer equipment off a generator (non inverter type). As you all know, this type of energy is quite dirty and nowhere near a pure sine wave.

a) Can computers run safely off of dirty electricity from a generator if you have a Line-Interactive UPS system that has an AVR that will adjust for small line fluctuations and surge protection? I understand the current will not be a pure sine wave,
b) If not, is the only course of action to buy an OnLine UPS Double-Conversion type, much more expensive unfortunately,
c) Are there any other options, e.g. an inverter along with surge protection.

Thanks

BillX

[Geek-9pm]

Here's a quick response.
Most modern gasoline powered generators have very clean outputs and you have little to worry about. But if you are in doubt, have a technician check it out with an oscilloscope and a dummy load to see what it looks like. I'm sure it'll be very close to 99% pure sine wave.

Now if you are talking about analog audio equipment, that is something else.
Some posts found elsewhere seem to be concerned about line noise, which is a big thing for analog audio recording work..

Now as to modern computers. Unlike some older analog electronic devices, modern computers and wide tolerance for power-line noise and trash. In fact, the computer itself uses a switching power supply which has the capability to produce more noise than you can imagine. Nevertheless, the DC output of the switching power supplies is very clean and state-of-the-art.
Some commercial operators prefer to have a UPS unit to ensure that the power is always extremely clean. However, in some cases the UPS is not as reliable as anything else. The UPS is more of a backup system and not really a guarantee that the power supply to your equipment will always be pure and steady.
If the generators well-maintained and used properly, it should provide steady clean power. One of the concerns is that the gas must be clean. And also the air intake manifold has to be checked regularly and you have to make sure no dust hits and. And of course, the gasoline generator must be well ventilated.
As I said, this is a quick answer based on my personal knowledge and experience.
Hope this is of some help.

[patio]

Gonna have to disagree on this one with Geek...1 of the best features of a UPS is clean steady power...it's the 2nd most important thing they do...after supplying backup power...

[BillX]

Thanks for replying, Geek and patio.

@Geek:

The clean generators you are referring to must be the inverter type, which are costing less nowadays, but I don't have one of those. An oscilloscope would be ideal if nothing else but curiosity. My signal might be better than I think, but most refer to non-inverter types as dirty power.

When you are saying UPS, are you referring to StandBy or Line InterActive. I understand that the standby units don't have a AVR and are pretty much surge protection with battery back-up, which might be enough in normal situations (non generator use). Line InterActive ones seem a good idea controlling even slight fluctuations, and with an inverter generator would have to be enough for sure, making an OnLine UPS overkill.

@patio

The promos refer to the pure sine wave output of StandBy, Line-InterActive and OnLine UPS's as very clean. But the first 2 will have no say in sine wave pattern coming from the grid or a generator. I thought that what comes from a generator is what you get re sine pattern, unless an OnLine is used.

Much appreciated to you both. More to consider here.

[Geek-9pm]

I will stick to my statement until proven otherwise.
The people who make UPS devices say they are good. But my own experiences is the are more often the cause of trouble.
Unless you have real measurements, it is guess work.
Here is a quote:

This nagging "power quality problem" had nothing to do with power quality. Why? With the information provided by a power disturbance analyzer, the engineers determined the following vital information:

He goes on to mention the 'failures' in a power system came for devices other than the generators. It was not 'dirty power', but another thing that made  the power  drop. There are far too many cases of where somebody blames the generator for bad power.

[DaveLembke]

a) Can computers run safely off of dirty electricity from a generator if you have a Line-Interactive UPS system that has an AVR that will adjust for small line fluctuations and surge protection? I understand the current will not be a pure sine wave,
b) If not, is the only course of action to buy an OnLine UPS Double-Conversion type, much more expensive unfortunately,
c) Are there any other options, e.g. an inverter along with surge protection.

Biggest thing with a generator for your home is to make sure you have the proper switchgear to isolate your generator from the utility pole. I have to be really careful here about what i say because I dont want to list any methods people have used to power their home (backfeeding) their breaker box which can at all be suggestive.   

Do you have a professionally installed generator? or just one of those portable gasoline ones like I have.

I live in an area of New England that loses power frequently. I have a Champion 6500 watt portable 120/240VAV with 7.7 gallon gas tank with a run time of about 11 hours on a full tank of gas.

I have learned with my generator that the standard off the shelf battery backups DO NOT LIKE being powered off of a generator. I even borrowed my brothers generator in which he has a better Honda brand generator and the battery backups in my home acted the same. They click about once click every second as it switches back and forth between passive mode sending the power to devices powered through it and then correcting for dirty sine wave in which it uses the battery. The last time we lost power for 7 hours and I had the generator going, the battery backup kept clicking as it was switching back and forth from passive to active power to the devices plugged into it. After about 4 hours the lead acid battery went dead in the 750VA battery backup as for all that compensating drained the sealed lead acid battery. The same battery backup without generator would keep all the same stuff going for about 20 minutes just off the battery only. So the problem with standard battery backups are that the use of the battery to compensate uses more power than is able to be stored back to the battery during the charge cycle when it switches back to passive.

You really should have a OnLine UPS Double-Conversion type as the solution.

Bare minimum protection from a generator is to have a surge protected power strip to protect from any spikes. Laptops are safer with generator power as for the power supply that charges the laptop battery has pretty good filtration as well as any dips the laptop battery if a healthy battery will keep the computer going without any problems. Desktop computers however really should be powered through the more expensive OnLine UPS Double-Conversion type.

I also have 12V Lead Acid Car Batteries and a 1000 watt inverter. I have been able to use a desktop computer drawing 165 watts for 2 hours on a 750 CCA battery that was recently charged. However during an outage its best to just use one of my laptops. The other benefit of laptop is that when the car battery dies I can swap out the car batteries to the next freshly charged battery and just keep going without having to shutdown the computer, while a desktop computer needs to be shutdown between each battery swap. I like using the car batteries if I need electric and need to be quiet. I have 2 truck batteries and a smaller battery from a Honda Civic that I use for silent power with my 1000 watt inverter.

[BillX]

Thanks for the Reply:

My generator is a mobile 6500 watts (running) - as yours, and hooks to a transfer switch at the metre. I don't know your UPS type (sounds like Line-InterActive). I understand that the AVR can handle moderate fluctuations without engaging the battery, but wider voltage variances require battery assistance. Almost certain my generator would cause the same thing as yours. And what you're describing is exactly what I'm trying to avoid, so thanks for sharing your experience.

Some here have recommended an inverter generator and that would be probably the best if money was no object, but I think by the nature of a motor supplying various equipment, you would still need some protection from fluctuations as other power draws in the house come into play. So some kind of regulation would be required, or at the very least, a Surge Arrest bar (IMO better than Surge Protection).

That's why an OnLine system does seem the best solution.

I thought of inverters but I believe that's really for running off batteries and not for my application.

Stove Power Specs:

Rated current during ignition A3.0 (Start up Amps)
Maximum power input during ignition W330 (Start up Watts)
Maximum power input at work W102 (running Watts)

So I'm looking at a small UPS OnLine system of 650W (5.8A). I'll have to verify that this is adequate but the specs indicate it is double the Wattage/Amperage I need.

Cheers

Biggest thing with a generator for your home is to make sure you have the proper switchgear to isolate your generator from the utility pole. I have to be really careful here about what i say because I dont want to list any methods people have used to power their home (backfeeding) their breaker box which can at all be suggestive.   

Do you have a professionally installed generator? or just one of those portable gasoline ones like I have.

I live in an area of New England that loses power frequently. I have a Champion 6500 watt portable 120/240VAV with 7.7 gallon gas tank with a run time of about 11 hours on a full tank of gas.

I have learned with my generator that the standard off the shelf battery backups DO NOT LIKE being powered off of a generator. I even borrowed my brothers generator in which he has a better Honda brand generator and the battery backups in my home acted the same. They click about once click every second as it switches back and forth between passive mode sending the power to devices powered through it and then correcting for dirty sine wave in which it uses the battery. The last time we lost power for 7 hours and I had the generator going, the battery backup kept clicking as it was switching back and forth from passive to active power to the devices plugged into it. After about 4 hours the lead acid battery went dead in the 750VA battery backup as for all that compensating drained the sealed lead acid battery. The same battery backup without generator would keep all the same stuff going for about 20 minutes just off the battery only. So the problem with standard battery backups are that the use of the battery to compensate uses more power than is able to be stored back to the battery during the charge cycle when it switches back to passive.

You really should have a OnLine UPS Double-Conversion type as the solution.

Bare minimum protection from a generator is to have a surge protected power strip to protect from any spikes. Laptops are safer with generator power as for the power supply that charges the laptop battery has pretty good filtration as well as any dips the laptop battery if a healthy battery will keep the computer going without any problems. Desktop computers however really should be powered through the more expensive OnLine UPS Double-Conversion type.

I also have 12V Lead Acid Car Batteries and a 1000 watt inverter. I have been able to use a desktop computer drawing 165 watts for 2 hours on a 750 CCA battery that was recently charged. However during an outage its best to just use one of my laptops. The other benefit of laptop is that when the car battery dies I can swap out the car batteries to the next freshly charged battery and just keep going without having to shutdown the computer, while a desktop computer needs to be shutdown between each battery swap. I like using the car batteries if I need electric and need to be quiet. I have 2 truck batteries and a smaller battery from a Honda Civic that I use for silent power with my 1000 watt inverter.

[Geek-9pm]

While doing a search, found this:

Two Generators Together.
Hard to believe:


I used to tell people that this is impossible. But now they really sell generators made to work together. This has some advantages. Think about it. 

[DaveLembke]

Interesting but pricey. Looks like it has an 80cc motor to power them.


Here is my 1000 Watt Inverter ... cost me $79.99 from Sears online on sale about 2 years ago. https://www.amazon.com/Cobra-CPI1000-1000W-Power-Inverter/dp/B00126AR40

Works great for as long as you have a 12VDC source with lots of Amps to pull from. As for 1 Amp of draw at 120VAC is pulling 10 Amps at 12VDC + the power conversion waste which brings it higher than 10 Amps through heat loss etc.

Before i owned a generator when I had power outages, I had a 750 watt Black & Decker inverter tapped off of a idling car in driveway with long heavy duty extension cord into kitchen window to run computer at about 200 watts, 7 watt cordless telephone, a 13 watt lamp, 12 watt cable modem, 13 watt 8 port switch, and 72 watt flatscreen TV, plus a 90 watt box fan if its summer. Costly power at the gasoline cost of a idlng Toyota Tacoma Pickup Truck. Fortunately I might have only had to burn a couple gallons of gasoline when gas was almost $4 a gallon. An actual generator would have made more electricity for lesser gasoline consumption. * I still have the 750 watt inverter so I could make up to 1000 + 750 watts continuous quietly for as long as the batteries last, but not greater than a 1000 watt draw because they are not teamed so up to 1000 watts on the one and up to 750 watts on the other with important stuff like refrigerator and lighting.